HomeMy WebLinkAboutAPA4093State of Alaska end the
U.S.Flah and Wlldllf.Service
July 1986
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Final Report
SUSITNA RIVER BASIN STUDY.ALASKA
SUMMARY OF USDA INVESTIGATIONS AND ANALYSES
Prepared by
United States Department of Agriculture
In Cooperation with
State of Alaska
and
United States Fish and Wildlife Serv1te
For further information.contact
State Conservationist
Soil Conservation Service
201 E.9th Avenue.Suite 300
Anchorage.Alaska 99501-3687
Telephone (907)261~2424
July 1985
ARLIS
Alaska~
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I.Introduction ~3
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,Execut1ve Summary
TABLE OF CONTENTS
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A,.Background....... . . . . . . . . . . .... . . ...... . . . . . . . . . . .... . .... . . . . . . . .... . .3
B.Study Object1ves 5
c.The Study Area.................................................6
II.Analyses and Results 7
A.Analys1s of benef1ts and costs assoc1ated w1th t1mber
and agr1cultural development ..................••...............7
B.Est1mates of state and local land demands for
agr1cultural and t1mber products ....••............•............9
C.Costs assoc1ated w1th access1ng agr1cultural and
t 1mt>er resources 13
D.Resource Inventor1es and Analyses .........................•....13
1.Water Resources 16
4.Geology 31
3.Land Treatment and Agronomy ...............•...............30
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2.So 11 s 29
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5.La"nd Cover 34
6.Recreat1on ~..37
7.Archeolog1cal,H1stor1cal,and .Cultural Resources 37
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;..:j 8.F1sh,W11d11fe and Wetlands ...........•..............•....39
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9.f100d Plains 41
E.Econom1c value of selected recreat10nal resources ....•.........55
F.Integrated automat1c data process1ng capab111ty ...........•....56
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III.Appendices 62
Appendix A -Supplementary Reports 62
Appendix B -Linear Programming Assumptions and Results 66
Appendix C - A Methodology for Estimating Road Costs 81
Appendix 0 -Computer Models for Land Suitability 93
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LIST OF TABLES
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Table 1.Ex1st1ng supply and demand of selected agr1cultural
conunod1t1es 11
..,Table 2.Total land demand for agr1cultural purposes 12
Table 3.Annual wood products demand ........•.•....•..•.....•...........14
--,Table 4.nmber land demand .•...............•......•.•.•.•.•...;15
Table 5.Data for mean-annual prec1p1tat10n map ...•.....................22
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Table 6.Seasonal d1str1but10n of prec1p1tat10n 1n the
Sus1tna R1ver Bas1n .....................•••....................23
Table 7.Est1mated mean annual evapotransp1rat10n 1n the
Sus1tna River Basin -23
Table 8.Stream gag1ng stat10ns 1n the Sus1tna R1ver Bas1n 24
Table 9.Mean annual water y1eld from L1ttle Sus1tna R1ver
above gag1ng stat10n no.15290009 ........•.......•...........•.25
Table 10.Mean annual water y1eld from Talkeetna R1ver above
gag1ng stat10n no.15292700 .........•...•.••...•.•............•26
Table 11.Mean annual water y1eld from Chu11tna R1ver above
gag1ng stat10n no.15292400 ..............•....•..•.•...........27
Table 12.Irr1gat10n crop y1eld response .....•.....•.....•.•......•....•.32
Table 13.Land cover mapp1ng un1ts ••........••.....•........•.........•.•36
Table 14.B1g game populat10n est1mates for the Sus1tna R1ver
Bas1n/Matanuska-Sus1tna Borough ..........••.•................•.41
Table 15.Preferred hab1tats for selected Sus1tna Bas1n mammals ..•.......42
Table 16.Summary of selected plant commun1ty (w11d11fe hab1tat)43
acreages
Table 17.Summary of 1nstruct10ns for hab1tat synthes1s model •....•.•..•.44
Table 18.Class1f1cat10n of wetlands 1n the Sus1tna R1ver Bas1n ........•.48
Table 19.Wetland types.Sus1tna R1ver Bas1n .......•........•.........•••49
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Table 20.Streams studied in the Susitna River Basin,and areas
of each subject to flooding (lOO-year flood plain)52
Table 21.Existing recreational demand 57
Table 22.Standards for selected recreational activities 58
Table 23.Existing recreational value,Susitna planning area,
excluding Willow Subbasin (1982 dollars)......•.•.............•59
Table 24.Fish and game protein values ............••..•............••....60
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Flood plain management study areas,Susitna River Basin 54
Talkeetna linear programming (lP)unHs .........•...........••8
Mean annual precipHation -SusHna River Basin .......•.....•~19
Mean annual water yield -Susitna River Basin ............•..•.20
Wetland identification matrix .......•.........................46
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Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6•
LIST OF FIGURES
Map of the Susitna River Basin
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Execut1ve Summary
Th1s report d1scusses 1nvest1gat10ns conducted by the U.S.Department of
Agr1cu1ture as part of the Sus1tna R1ver Bas1n Study.-Major f1nd1ngs
resu1t1ng from these 1nvest1gat10ns are as follows:
1.Under only very restr1ct1ve assumpt10ns.e.g.zero road construct10n and
zero stumpage costs.1s large scale agr1cu1tura1 and/or t1mber development
econom1ca11y feas1b1e.
2.,In order to become se1f-suff1c1ent 1n terms of agr1cu1ture.the State of
Alaska would need roughly 1 m11110n acres of land 1n product10n.
3.Under ex1st1ng cond1t10ns.demand from Anchorage and the Matanuska-Sus1tna
Borough for t1mber land totals about 1.8 m11110n acres.
4.Approx1mate amounts of state-owned bas1n land 1dent1f1ed as be1ng
phys1ca11y capable of support1ng var1ed uses are as follows (these acreages
are not mutually exc1us1ve):
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a.Agr1culture
b.nmber
400.000 acres of cu1t1vab1e s011s.
900.000 acres w1th h1gh or moderate potent1al for
commerc1a11/t1mber management.
c.Settlement-..
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700.000 acres.(In add1t10n.360.000 acres of
Nat1ve-owned and 300.000 acres of non-Nat1ve-owned
pr1vate land are phys1ca11y su1ted for settlement;1n
add1t10n to much of the borough's approx1mate1y
350.000 acres.Most pr1vate and borough settlement
lands have better road access than state-owned
settlement lands.)
5.W1th1n the Beluga and Talkeetna port10ns of the bas1n.approx1mate1y 3.8
m11110n wetland acres were 1dent1f1ed.
6.F100dp1a1n management stud1es 1dent1f1ed approx1mate1y 329.000 acres
w1th1n the 100-year flood p1a1n.
7.The present value of selected recreat10na1 act1v1t1es tak1ng place w1th1n
the bas1n 1s 220.7 m11110n dollars.
8.Un1t values of selected f1sh and game spec1es were calculated and are
1nc1uded 1n th1s report.
1/Commerc1a1 forest land:Forest land produc1ng or capable of produc1ng
crops of 1ndustr1a1 wood and not w1thdrawn from t1mber ut111zat10n.Areas
qua11fy1ng as commerc1a1 forest land have the capab111ty of produc1ng 1n
excess of 20 cub1c feet per acre per year of 1ndustr1a1 wood under management.
9.A methodology was developed for identifying a minimum land base necessary
for maintenance of fish and wildlife resources.
10.A methodology was developed for estimating costs associated with accessing
basin land.
11.Three cultural resource inventories and assessments were prepared and are
summarized in this report.
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I.Introduction
A.Background
In recent years.the State of Alaska and the Hatanuska-Sus1tna Borough have
been transferring land to private ownership in the Sus1tna River Basin.These
transfers are often accompanied by title restrictions for each particular
parcel in question.i.e .•the state or borough withholds certain development
rights and allows only land uses it deems are best suited.
In the past."best uses"were at times determined with insufficient data
because adequate inventory information simply did not exist.As a result.in
many instances inappropriate uses evolved on basin lands.For example.homes
were built in flood plains and septic tanks were constructed in or adjacent to
wetlands.In,addit1on to physical compatibility problems.social and
environmental tradeoffs became major issues.The best wildlife land was at
times the best agricultural or urban land.and disposal of land for its "best
use"became even more subjective .
Realizing these problems would grow with both increasing population and demand
for land for all uses.and interested in deve10ptng a data base for evaluating
and selecting appropriate land uses.the Alaska Department of Natural
Resources (ADNR)requested technical assistance from the U.S.Department of
Agriculture.Soil Conservation Service (SCS)in February 1976.In response.
the USDA.in June 1976.authorized the Alaska River Basin Study under Public
law 83-566 (Watershed Protection and Flood Prevention Act of 1954).
Public law 83-566 provides broad authority for cooperation between USDA
agencies and other Federal and state agencies in river basin planning.
surveys.and investigations.The SCS directs these activities.working
closely with the USDA Forest Service (FS)and Economic Research Service
(ERS).Conducted at the request of cooperating agencies.in this case the
ADNR.river basin studies are undertaken to:
-identify water and land resource problems.
analyze the economic base and environmental setting of the study
area.and
-suggest alternative-plans for solving identified problems and
improving the economy and environment.
In February 1979.a plan of work for the Sus1tna River Basin Study was
adopted.For study purposes.the Sus1tna River Basin was divided into four
subbasins:Willow.Talkeetna.Beluga.and Upper Sus1tna (Figure 1).The
Willow Subbasin Study was scheduled first.Completion of that study resulted
in a land use plan for the Willow Subbasin.published in October 1982 as:
Willow Subbasin Area Plan.A land Use Plan for Public lands (ADNR.Hatanuska-
Sus1tna Borough.ADF&G.with the assistance of the USDA SCS).USDA activities
during that study are summarized in:Sus1tna River Basin Study -Alaska.
Willow Subbasin (USDA in cooperation with the State of Alaska and the U.S.
Fish and Wildlife Service.1981).After completion of the W1110w land-use
plan.a combined study of the final three subbasins was initiated.
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Alaska Department of Natural Resources
555 Cordova Street
Anchorage,Alaska 99510
Telephone (907)561-2020
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This report summarizes information gathered and developed by the USDA during
the combined study of the Talkeetna,Beluga,and Upper Susitna Subbasins.
Although this report is not meant to stand alone as the final river basin
report,it informs readers of types of data collected and analyses made by the
USDA.The land-use'plan developed using these data and analyses is d~scribed
in:Susitna Area Plan.Public Review Draft -Summary (ADNR,ADF&G,
Matanuska-Susitna Borough,in cooperation with ADOTPF,Kenai Peninsula
Borough,USDA,and BLM,1984).
Supplementary reports discussed herein are listed in Appendix A.These
reports,maps and computerized data are available at either:
U.S.Department of Agriculture
Soil Conservation Service
201 E.9th Avenue,Suite 300
Anchorage,Alaska 99501-3687
Telephone (907)261-2424
B.Study Objectives
Reasons for state and borough participation in this study are obvious:as
they transfer their lands to the private sector,they must determine both the
locations and amounts of land to transfer for each type of land use,e.g.,for
agriculture,timber,settlement,etc.To assist the state and borough in
making decisions about which lands to transfer,the USDA undertook to provide
resource data and analyses that would facilitate state and borough land use
planning and management in the Susitna River Basi~.
More specifically,the state and borough requested that the USDA provide the
following information and assistance:
1.An economic analysis of the benefits and costs associated with
timber and agricultural development in the Susitna Basin.
2.Estimates of state and local land demands for agricultural and
timber products,i.e.the amount of land required for the state.to become
self-sufficient in agricultural and timber production.
3.Based on the results of number 1 above,a determination of costs
associated with accessing agricultural and timber resources.
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4.Resource inventories and analyses of the following:
a.water resources
b.so11s
c.land treatment and agronomy
d.geology
e.land cover and vegetation
f.recreation
g.archeological,historical,and cultural resources
h.fish and wildlife and wetlands
i.flood plains
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5.Estimates of the economic value of selected recreational
resources within the basin.
6.Assistance 1n developing an integrated automatic data processing
capability to handle collected resource data.
Each of the preceding objectives is addressed in more detail in the "Analys1s
and Results"section of this report.
C.The Study Area
The Sus1tna River Basin encompasses approximately 14 million acres in
Southcentral Alaska (Figure 1).Of this total,about one million acres lie in
the Willow Subbasin,for which a similar study has been completed and
published (Sus1tna River Basin Study -Alaska:Willow Subbasin Final Report,
1982,USDA in cooperation with the State of Alaska and the U.S.Fish and
Wildlife Service).The remainder of the basin,addressed in this report,
extends from Cook Inlet on the south to the Alaska Range on the north,
Clearwater Mountains on the northeast,Lake louise area o"n the east,and
Tordr1110 Mountains on the west.Major stream systems are the Sus1tna,
Talkeetna,Chulitna,Kahiltna,Skwentna,Yentna,and Beluga Rivers,and the
lower reaches of the Chakachatna River.Lakes 1n the area number in the
hundreds,among the largest are Lake Louise and Beluga Lake,as well as
Alexander,Strand11ne,Trapper,Shul1n,Chelatna,and Amber Lakes.
Basin communities (excluding those in the Willow Subbasin)include Talkeetna,
Skwentna,Trapper Creek,and Tyonek.The study area includes most of the
Matanuska-Sus1tna Borough and the northwestern portion of the Kenai Peninsula
Borough.The study area is traversed from north to south by the Parks Highway
and the Alaska Railroad.Access to much of the area is.primarily by airplane,
boat,or all-terrain vehicle.
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II.Analyses and Results
This section is divided into six subsections,one for each of the objectives
listed above.Each subsection contains four parts:1)restatement of the
objective,2)rationale for the objective,3)discussion of research conducted
to meet the objective,and 4)a summary of research and analysis results .
A.Objective:Provide an economic analysis of the benefits and costs
associated with timber and agricultural development in the Sus1tna Basin.
Rationale:To determine whether or not state and borough land
disposals for agricultural and timber development are economically feasible.
Analysis:In this analysis,returns from investments (benefits)were
compared with investment expenditures (costs)for several agricultural and
timber development activities.Costs considered included road construction,
land clearing,and other operations associated with logging and farming;and
these were evaluated for several sets of alternative economic conditions.The
primary benefit measured was dollar value of increased supply of commodities
resulting from investment activities,commodities in this case being barley,
saw10gs,and fue1wood.
In order to examine development costs associated with undertaking agriculture
or timber production in specific locations;that is,in order to facilitate
"d1saggregated"and geographically localized analysis,the study area was
subdivided into 50 smaller areas called land production (lP)units
(Figure 2).The lP units were delineated in areas where the best soil and
timber resources are located,as indicated by soil and vegetation surveys.
The analysis identified benefits and costs of 25 different alternatives,with
each alternative being characterized by 21 parameters or variables,such as
changing market prices,different crop yields,etc.Appendix B identifies the
variables (assumptions)used in the analysis and presents the results of
analyzing each alternative.
Results:Results from analysis of alternatives 1 through 4 indicate
that barley production is not profitable at an export price of $3.12 per
bushel .
Of the remaining 21 alternatives,13 indicated a positive net benefit from
domestic barley production.The number of acres that could feasibly be put
into production ranged from a low of 2.096 in alternative no.6 to a high of
'273,512 in no.23.Six of the economically beneficial alternatives suggested
that it could be feasible to bring 150,000 acres or more into production;
however,the USDA considers one or more of the assumptions used in these six
alternatives to be overly optimistic at this time,i.e.the USDA does not
recommend large-scale barley production in the Susitna River Basin at this
time.Results indicate that economic feasibility is most sensitive to
production costs,yields,and prices received.
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From the standp01nt of t1mber products,"analys1s 1nd1cates that product10n 1s
econom1cally feas1ble under almost all alternat1ves evaluated.Two very
1mportant p01nts to note are:
1.stumpage costs,1.e.the costs of the r1ght to cut t1mber,were
zero 1n all alternat1ves,and
2.In only one of the 25 alternat1ves were prof1ts h1gh enough to
pay for road construct10n.
In short,1f free cutt1ng 1s allowed and ex1st1ng roads are used,.prof1ts can
be made.Otherw1se 10gg1ng operat10ns become marg1nal g1ven current pr1ces
and cutt1ng methods.For further d1scuss10n of these econom1c analyses,refer
to Append1x B.
B.Object1ve:Prov1de est1mates of state and local land demands for
agr1cultural and t1mber products,1.e.the amount of land requ1red for the
state to become self-suff1c1ent 1n agr1cultural and t1mber product10n.
Rat10nale:To prov1de 1nformat10n sought by s1gn1f1cant
spec1al-1nterest groups w1th1n Alaska,as well as by leg1s1ators,who be11eve
pursu1ng the goal of self-suff1c1ency 1n these commod1t1es has many des1rable
effects,among wh1ch 1s greater secur1ty for Alaskans 1n t1mes of
1nternat10nal cr1ses when routes of supply may be severed.
Analys1s:
1.Agr1cultural Analys1s
Th1s analys1s 1dent1f1ed the total number of product1ve acres needed to
ach1eve self-suff1c1ency 1n those crops that can be grown 1n Alaska.Total
acreage f1gures are 'based on both per cap1ta demand and land requ1red 1n
product10n to meet demand.
Number of acres needed 1n product10n depends heav11y on crop y1eld assumpt10ns
and human populat10n project10ns.There are 1mmense d1fferences 1n the
ab111ty of var10us parcels of land to produce a part1cular quant1ty and
qua11ty of a certa1n crop.S1nce y1elds and y1eld project10ns vary greatly at
d1fferent t1mes and 1n d1fferent areas of Alaska,the amount of land needed to
sat1sfy 1n-state demand for d1fferent agr1cultural products has been
calculated under var10us y1eld assumpt10ns.The h1gher the assumed y1eld,the
less land 1s requ1red to produce a part1cular quant1ty of product.
Th1s analys1s does not cons1der whether or not meet1ng the 1n-state demand
from local supp11es 1s econom1cally feas1ble.
2.T1mber Analys1s
The forest products demand analys1s 1dent1f1ed the Matanuska-Sus1tna Borough
and Anchorage demand for selected t1mber products,as well as the land base
necessary to prov1de these products.As 1n the Agr1cultural land Demand
analys1s,no cons1derat10n was g1ven to whether or not meet1ng th1s demand
w1th Alaskan sources would be econom1cally feas1ble.
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Results:
1.Agricultural Results
Tables 1 and 2 summarize the results of the agricultural analysis.
Information developed indicates that land required to meet current in-state
demands for Alaskan agricultural products ranges from 666,200 to 1,216,000
acres,while year 2000 demand requires production from somewhere between
1,065,100 and l,944~000 acres.Midpoint cropland needs for existing and
projectedyear-2000 populations are 941,100 and 1,504,550 acres,
respectively.All acreage figures in Table 2 (e.g.,those cited above)
represent "harvested"as opposed to "planted"acres.On the average
nationwide,for years 1978,1979,and 1980,planted acres exceeded harvested
acres by about 10%;therefore,estimating total agricultural land required to
meet in-state crop demand requires an adjustment to account for this 10%
discrepancy.Adjusted midpoint land requirements for existing and projected
year-2000 populations are 1,035,200 and 1,655,000 acres,respectively.
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Table 1.Existing Supply and Demand of
Selected Agricultural ConunodH1es
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:Per ·Total :1981·~-Agricultural :CapHa II Alaska y :Alaska :Imports to the State:
ConrnodHy :Demand ·Demand .Supply :Ouantity :Percent,·.
(lbs.)(1000 (1000 (1000
1bs.)1bs.)1bs.)
Potatoes 74.8 31,580 9,500 22,080 69.9
.;;66,832 2,320 YVegetables158.3 64,512 96.5,
Beef &Veal 124.3 !I 52,478 749 51,729 98.6
lamb &Mutton 2.0 !I 844 18 826 97.9
J Pork 56.1 !I 23,685 293 23,392 98.8
Poultry 49.3 il 20,814 231 20,583 98.9
-ei Ml1k 546.0 ~I 230,514 13,400 217,114 94.2
';Eggs 35.4 §.I 14,945 874 14,071 94.2
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11 USDA Agric.Statistics and USDA Food Consumption,Prices,and
;;Y Expenditures (Nationwide averages).
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£1 Assuming a 1981 Alaska population of 422,187.Source:Alaska
Population Overview -1981,Alaska Department of labor.
y Represents 1980 supply;1981 figures not available.
il Dressed weight -For poultry,dressed wt.and retail wt.are assumed to
be equal.
~Represents milk equivalent of per capita demand for all dairy products.
!I 1 case =30 doz.eggs =47 1bs.(7.66 eggs =1 lb.).
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1/Source:Alaska Economic Projections for estimating electricity
requirements for the rai1belt,Batelle Pacific Northwest Labs.-
moderate projection.
40 bu.barley and 1.0 tons hay 1.204.500 1.925.700
Barley
50 bu.barley and 1.5 tons hay 939.800 1.502.500
and
60 bu.barley and 2.0 tons hay 773.400 1.236.600
Hay
70 bu.barley and 2.5 tons hay 658.200 1.052.300
70 Cwt.9.700 15.500
80 Cwt.8.400 13.500
Vegetables
90 Cwt.7.600 12.100
100 Cwt.6.800 10.800
9 tons 1.800 2.800
10 tons 1.600 2.600
Potatoes 11 tons 1.400 2.300
12 tons 1.300 2.100
13 tons 1.200 2.000
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Total -assuming highest yields 666.200 1,065,100
Total -assuming lowest yields 1,216,000 1,944,000
Table 2.Total Land Demand for Agricultural Purposes
Crop Assumed yield per acre
Total Demand
1983 :2000
(Pop.=422.187):(Pop.=674.983)1/
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2.Timber Results
Results of the timber analysis are shown in Tables 3 and 4.Information
developed shows that meeting timber product demand requires between 921,600
acres and 2.987,840 acres.
C.Objective:Determine costsl1 associated with accessing
agricultural and timber resources.
Rationale:To enable planners and others to identify the most
desirable road access routes on the basis of their relative costs.
Analysis:During analysis of road costs.a methodology was developed
that can be used to evaluate costs of alternative road routes within the
basin.Since the methodology is a I'short cut ll summary in itself,it is
presented in its entirety in Appendix C.
Results:See Appendix C.
D.Objective:Conduct resource inventories and analyses of the
fo11Q.w1ng:
1.water resources
2.soils
3.land treatment and agronomy
4.geology
5.land cover and vegetation
6.recreation
7.archeological.historical.and cultural resources
8.fish and wildlife and wetlands
9.flood p1a1ns
Rationale:The 1nherent capability of an area to support particular
land uses is a function of physical and biological conditions (e.g .•soils.
flood history,vegetation,geology,etc.)characterizing that area.and how
those conditions promote or constrain implementation of land uses in
question.Inventorying physical and biological resources and conditions is.
therefore,an essential prerequisite to land capability analysis.
II All costs shown are rough estimates only and are not meant.to be used as a
substitute for lion the ground II reconnaissance and subsequent detailed design
and cost work.The purpose of this information is to enable planners and
others to identify the more desirable routes of access by means of
establishing re1at1vecosts among route selection alternatives.Unless
otherwise noted all costs are on a 1983 price base.
-13 -
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2.T1mber Results
Results of the t1mber analys1s are shown 1n Tables 3 and 4.Informat10n
developed shows that meet1ng t1mber product demand requ1res between 921,600
acres and 2.987.840 acres.
C.Object1ve:Determ1ne costsl1 assoc1ated w1th access1ng
agr1cultural and t1mber resources.
Rat10nale:To enable planners and others to 1dent1fy the most
des1rable road access routes on the bas1s of the1r relat1ve costs.
Analys1s:Dur1ng analys1s of road costs.a methodology was developed
that can be used to evaluate costs of alternat1ve road routes w1th1n the
bas1n.S1nce the methodology 1s a "short cut"summary 1n itself,it 1s
presented 1n 1ts ent1rety 1n Append1x C.
Results:See Append1x C.
D.Object1ve:Conduct resource 1nventor1es and analyses of the
follow1ng:
1.water resources
2.so11s
3.land treatment and agronomy
4.geology
5.land cover and vegetat10n
6.recreat10n
7.archeolog1cal,h1stor1cal.and cultural resources
8.f1sh and w11d11fe and wetlands
9.flood pla1ns
Rat10nale:The 1nherent capab111ty of an area to support part1cular
land uses 1s a funct10n of phys1cal and b1010g1cal cond1t10ns (e.g.,s011s,
flood h1story,vegetat10n,geology,~tc.)character1z1ng that area.and how
those condit10ns promote or constra1n 1mplementat10n of land uses1n
quest10n.Inventory1ng phys1cal and b1010g1cal resources and cond1t10ns 1s,
therefore.an essent1al prerequ1s1te to land capab111ty analys1s.
II All costs shown are rough est1mates only and are not meant.to be used as a
subst1tute for lion the ground II reconna1ssance and subsequent deta11ed des1gn
and cost work.The purpose of th1s 1nformat10n 1s to enable planners and
others to 1dent1fy the more des1rable routes of access by means of
estab11sh1ng relat1vecosts among route select10n alternat1ves.Unless
otherw1se noted all costs are on a 1983 pr1ce base.
-13 -
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Demand 1/
Origin -
Annual Mat-Su (1983)
Annual Anchorage (1983)
Annual Total (1983)
Annual Mat-Su (2000)
Annual Anchorage (2000)
Annual Total (2000)
Table 4.Timber Land Demand
Assumed Volume Per Acre
(Net Cubic Feet)
1246 .1500 :1800 :2100 :2400.
Existing
acres
3,534 2,935 2,446 2,096 1,836
18,654 15,496 12,913 11,068 9,685
22,188 18,431 15,359 13,164 11,520
11,239 9,336 7,780 6,669 5,835
26,109 21,688 18,073 15,491 13,555
37,348 31,024 25,853 22,160 19,390
-.80-year £I Total (1983)1,775,040 1,474,480 1,228,720 1,053,120 921,600
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80-year lotal (2000)2,987,840 2,481,920 2,068,240 1,772,800 1,551,200
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1/PopUlations used were as follows:
Mat-Su (Includes Tyonek)-1983 =23,717
Mat-Su (Includes Tyonek)-2000 =75,431
Anchorage -1983 =179,410
Anchorage -2000 =251,102
£I Assumed rotation period.
-15 -
Results:Rtver Bastn tnventortes werecarrted out etther dtrectly by
the USDA (forest Servtce,Sotl Conservatton Service,and/or Economtc Research
Servtce)or under contract to the USDA.In most cases,tnventory methods used
and results obtatned aredescrtbed tn a separate report for each tnventory.
These indivtdual reports are refere~ced below and,where practtcable,also
summarized.In addHton,all supplementary reports dtscussed below are listed
tn Appendtx A.No separate report was publtshed etther for the geologtcal
tnventory (whtch represented a synthests of extsttng USGS*and DGGS*data
rather than a collectton of new data)or for the determtnatton of annual bastn
p'rectpHatton and water ytelds.Results of these tnventortes and analyses are
presented tn thetr enttrety tn thts report.
Data c,ollect"ed durtngresource tnventortes were ut"tzed tn developtng land
capabtltty m6dels,dtscussed tn Sectton'f.As descrtbed tn Sectton f,model
results were mapped,and those maps were used by the Alaska Department of
Natural Resources and the Matanuska-SusHna Borough tn maktng land-use
dectstons.See Sectton f for a dtscusston of the uses of these tnventortes
~urtng land-use planntng.
Inventortes:
1.,Water Resources
Durtng the water resources tnventory,Susttna Bastn prectpttatton,water
ytelds,water su~pltes,and water qualtty were examtned.Three reports were
prepared detatltngthese examtnattons.The ftrst:Susttna Bastn Water
Qualtty Report (B.Rummel,no date)tdenttftes and examtnes water qualtty data
tn terms of the tssues and dectstons factng land use planners and resource
developers tn the Wtllow and Talkeetna Subbastns.Recommendattons for
matntatning water qualtty are provtded.
The second report:Susttna Bastn Planntng Background Report -Water Supply
and Demand (B.Loeffler,1980)dtscusses water resource data avatlable for the
bastn,analyzes current water suppltes and potenttal problems for etght bastn
communtttes,and addresses tn general terms water resource concerns related to
agrtculture.placer mtntng,and tnstream flows.
The thtrd report:Susttna Rtver Bastn Study -Prectpttatton and Water Yteld
(J.E.Merrell,1979)conststs of two maps,one deptcttng mean annual water
ytelds,the other,mean annual prectpttatton;and an accompanytng narrattve.
Because of the ltmtted dtstrtbutton and brevtty of thts unpubltshed report,tt
ts presented tn tts enttrety below.
*USGS:U.S.Geologtcal Survey;DGGS:Divtston of Geologtcal and
Geophystcal Survey,Alaska Department of Natural Resources.
-16 -
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Mean Annual Precipitation and Water Yield in the Sus1tna River Basin
Summary
Maps representing mean annual precipitation (Figure 3)and mean annual water
yield (Figure 4)were developed for the Sus1tna River Basin-for the purpose of
estimating these two important segments of the hydrologic cycle at any
location.Data were collected from 30 climatological and 9 stream-gaging
stations in the basin.and from 6 stream-gaging stations near the basin.Only
four of the climatological stations have records longer than 15 years.
Mean annual precipitation in the lowlands was estimated directly from
available precipitation data;mean annual water yield was then computed as
precipitation minus evapotransp1rat1on*.In gaged watersheds lacking
precipitation data.mean annual water yield was estimated by distributing
measured runoff according to elevation;runoff-elevation relationships were
then extrapolated to ungaged watersheds to estimate their annual water
yields.Once annual water yields were determined.mean annual precipitation
was computed by adding mean annual water yield and evapotranspiration.
Evapotranspiration values were developed in a separate study.
Some inconsistencies exist between lowland and upland values of both
precipitation and water yield.These arise because estimates for mountainous
areas were based on volume measurements from large areas while estimates for
lowland areas were based on point measurements by rain gages.which are
generally understood to represent a little less than true precipitation.
Errors in mapped values are felt to be less than 25%above or below true
values.
Physical Setting
The study area included the entire Sus1tnaR1ver drainage.as well as
drainages of the Beluga and Theodore Rivers to the west.Tree line in these
watersheds ranges from 1000 to 200n feet above sea level.Below that line.
mixed white spruce and birch forests are common on well-drained sites and
black spruce forests or muskegs in wet areas.Soils are generally shallow
over gravel or glacial till;a deep layer of organic material in various
stages of decomposition is common.Vegetation above timber line includes
sedges.grasses.herbs.and dwarf shrubs;with stands of alder between tree
line and alpine areas.Willows and alders are common along stream channels.
both at lower and higher elevations.
*Precipitation minus evapotranspiration equals water yield;alternatively.
evapotranspiration plus water yield equals precipitation.Water yield
consists of stream and groundwater outflow .
-17 -
Basin climate is "Trans1t1ona1~"between "Maritime"and "Continental"Climate
Zones (see C.W.Hartman and P.R.Johnson.Environmental Atlas of Alaska.
1978.Inst.of Water Resources.University of Alaska.Fairbanks).Mean annual
temperature ranges between 25°and 35°F.with pronounced temperature
variations throughout the day and year.local storms are generally caused
when moist air flowing up Cook Inlet from the southwest is cooled.either by
orographic uplift or by overriding cold air from Mt.McK1n1ey's glaciers.
Cold air draining off mountains and underr1d1ng moist incoming air causes
heavy precipitation 10 or 20 miles from the foot of basin mountains.
Purpose of the Maps
The maps presented in Figures 3 and 4 were developed to facilitate accurate
estimates of mean annual precipitation and mean annual water yield anywhere in
the basin.Very little of the area is developed.and precipitation has been
measured at only a few points.Much development seems possible and the
feasibility and nature of most development depends upon hydrology at proposed
sites.For example.developers need to know:how much snow must proposed
buildings support?how much water will be available in certain areas for use
or disposal?The maps presented here can be used to answer such questions.
In addition.seasonal patterns of precipitation are indicated in Table 6.
The water yield map must be used wHh caution in areas wHh permeable
substrata.The map indicates how much water an area w111 yield.but H'cannot
specify whether that water will run off the surface or will percolate into the
groundwater system and reappear elsewhere.
Previous Work
The most recent mean annual precipitation map was prepared in 1977 by
James Wise.Alaska State Climatologist.He recorded on a 1:1.000.000 scale
map of Alaska all precipitation data available.and drew 1sohyets based on
them.Orographic effects were accounted for qualitatively becaus~then (as
now)few data were available to quantify precipitation in the mountains.His
map is considered useful for reconnaissance purposes.
Mean annual water yield had not previously been expressed as mapped 1s011nes.
J.W.Freethey and D.R.Scully of the U.S.Geological Survey had.however.
derived a formula for its computation.In their pUblication Water Resources
of the Cook Inlet Basin.Alaska (1980.USGS.HA 620).they computed mean
annual runoff volume from watershed area.elevation.and precipitation.They
used precipitation data from Wise's map.and their results are usable for
reconnaissance purposes.
Evapotranspiration data necessary to relate mean annual precipitation to mean
annual water yield were developed in 1979 by E.Merrell of the Soil
Conservation Service.He calculated evapotranspiration rates from pan
evaporation data collected at the Matanuska Agricultural Experiment Station.
Palmer.Pan data were extended to higher elevations on the basis of
relationships discussed by Patr1c and Black in Potential Evapotranspiration
and Climate in Alaska by ThornthwaHe 's Classification (1968.,USDA Forest
Service Research Paper PNW-71.Juneau.Alaska).'
-18 -
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M7-N-24165-1
Mean Annual Precipitation in Inches
Source:
Bo ..map p<epored by.SCS,WTSC Carlo Un;!from USGS 1:1,000,000 Not.Alios.
U.S.DEPARTMENT OF AGRICULTURE SOIL CONSERVATION SERVICE USOASCS·PORTlANO.OR '98'
----30
MEAN ANNUAL PRECIPITATION
SUSITNA RIVER BASIN
ALASKA
AUGUST 1981
10 0 10 20 MILESHI!!!!IiiiiiiiI~~~~!!'!!!!'!!!!!!~'
SCALE 1,I ,000,000
+
M7-N-24165-2
Mean Annual Water Yield'In Inches
+
30
10t=1C::~iiI!!!!iiiiiiiI!~S~C:Al~Eo;;l ,~1,~000~~'000~10~~!!!!!",,"";20 MILES'
MEAN ANNUAL
SUSITNA RIVEWRATER YIELDBASIN
ALASKA
AUGUST 1981
KNIK J
Sowce,:6~~-
map p<epo",d by SCS,WTSUS CCortoU'..DEPARr'MENT OF AG n,t hom USGS 1,1,000RICULTURE,000 Not.Atla.
SOIL CONSERVATION SERVICE •USDA SCS PORTLAND.OR 1981
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Data Available
Long-term precipitation records (15 or more years of ~ata)were available from
only one station in the basin (Talkeetna).short-term records were available
from 12 stations.In addition.long-term records were available from
Matanuska Agricultural Experiment Stat10n.Palmer;Anchorage Airport.and
Elmendorf Air Force Base.Anchorage;and short-term records were available
from 17 other stations in the v1c1n1ty of the basin.These data were used to
determine bas1n precipitation.Very short records (as short as 2 years)were
used by correlating them with prec1p1tat10n at appropriate long-term stations.
and thence to mean annual precipitation.All precipitation data were used as
recorded;that is.they were treated as accurate point samples of total
prec1p1tat1on even though it is probable that each ra1n gage actually measured
less than total precipitation at its location.
Mean annual precipitation at sites throughout the basin is presented 1n
Table 5 (along with mean annual temperature and potential evapotransp1rat1on
values computed by Patrie and Black).Seasonal distribution of basin
precipitation was computed from three stat10ns with long-term records.and is
presented in Table 6..
-21 -
Table 5.Data for Mean Annual Precipitation Map
From Climatological Data :From Patrie
and Black
Mean :Potential
Eleva-:Annual:Evapotran-
Station :MAP *:Latitude:Longitude:t10n :Temp.:sp1rat1on
(inches):(North):(West):(feet):(OF):(inches)
Anchorage 14.74 61°13'149°52 1 118 35.3 19.25
Beluga 25.61°11'151°02 1 75
Big Lake 20.7 61°34'149°58 1 180 32.8 18.06
Caswell 25.06 61°58 1 150°01 1 290 31.0 18.66
Chickaloon 14.00 61°48 1 148°27'929 32.7 18.11
Chulitna H~y.Camp 42.1 62°24'150°15'500
Chulitna R.Lodge 37.62°53 1 149°50 1 1250
Curry 43.67 62°37'150°02 1 516 34.9 18.94
Eagle R.South Fork 21.61°14 1 149°26 1 2140
Edgem1re Lakes 40.6r 32 1 150°17'760
Elmendorf 16.24 61°14 1 149°52'192 34.8 19.65
Eklutna Lake 12.68 61°24 1 149°09 1 882 30.7 16.93
Eklutna Project 18.46 61°28'149°10 1 38 33.7 19.25
Glen Alps 27.61°06'149°41 1 2260
Healy 17.25 63°51'148°58'1350
Goose Bay N1ke Site 13.63 61°24 1 149°51 1 100
High Lake Lodge 24.5 62°54 1 149°05'2760 27.1 14.18
Indian River 36.7 62°45 1 149°50'735 31.1 16.97
Matanuska 15.49 61°34 1 149°16 1 150 35.5 19.76
McK1nley Park 15.12 63°40'149°00 1 2092 27.5 14.6.1
Moose Run 19.2 61°15'149°40 1 395 33.0 17.43
Mt.Magnificent 11.61°18 1 149°26'1000
Rock Ridge Dr.20.61°07 1 149°45'840
Summit N1ke Site 30.7 61°15 1 149°33 1 3980 29.3 12.69
Skwentna 25.96 61°57 1 151°10 1 153 32.6 18.46
Summ1 t 20.06 63 0 20'149 0 09 I 2401 25.8 15.51
Susitna 28.05 61°30'150°40 1 40 36.0 19.76
Talkeetna 28.64 62°18 1 150°06 1 345 33.2 18.70
Tyonek 21.61°04 1 151°08'50 35.3 19.57
Wasilla 2NE 19.61°37 1 149°24 1 500
Was1l1a 3S 18.61°32 1 149°26 1 50
Whites Crossing 22.61°42'150°00 1 251
Willow Trading Post 23.61°45'150°03 1 600 32.4 17.28
*MAP =mean annual precipitation.
-22 -
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Table 6.Seasonal Distribution of Precipitation in the Sus1tna River Basin
(monthly percentage of mean annual precipitation)
Matanuska Ag.:Palmer IN .Talkeetna :Used for Study.
Exp.Station
January 5 6 6 6
February 4 4 6 5
March 3 3 5 4
April 3 4 4 4
May 5 5 5 5
June 10 10 8 9
July 16 15 12 13
August 18 18 17 18
September 15 16 16 16
October 9 8 9 8
November 6 6 6 6
December 6 5 6 6
Annual 100 100 100 100
Mean annual evapotranspiration was calculated from evaporation and temperature
data.and was estimated to be 15 inches for areas below 1000 feet elevation.
Estimated mean annual evapotranspiration for higher elevations are presented
in Table 7.
Estimated Mean Annual Evapotranspiration
in the Sus1tna River Basin
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Elevation
(feet)
below 1.000
2.000
3.000
4.000
5.000
6.000
7.000
8.000 and above
-23 -
Estimated Evapotranspiration
(inches per year)
15
12
9
7
6
5
4
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Table 8.Stream Gaging Stations in the Sus1tna River Basin
Streamflow data are available from nine gaging stations in the basin.Data
from these stations are presented in Table 8.
Gaging Station
(location)
Drainage Area
(square mlles)
Mean Annual Runoff
(in .Iyr.)
Mean £lev.
(feet)
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Sus1tna River near Denali 950 38.53 4510
Maclaren River near Paxton 280 47.34 4520
Sus1tna River near Cantwell 4140 20.65 3560
Sus1tna River near Gold Creek 6160 21.40 3420
Talkeetna River near Talkeetna 2006 27.66 3630
Chulitna River near Talkeetna 2570 46.22 3760
little Sus1tna River near Palmer 61.9 44.54 3700
Skwenta River near Skwenta 2250 37.28 2810
Chu1tna River near Tyonek 131 33.85
Streamflow data from two stations on the Nenana River (7l0-square-m1le and
19l0-square-m1le drainage areas),and from stations on the Teklan1ka and
Chakachatna Rivers,and Seattle and Caribou Creeks,were used to estimate
runoff near the borders of the basin.
Gaging station records were long enough that measured average annual runoff
was felt -to represent long-term means.Frequency computations of individual
station records indicated that mean'runoffwas very ~lose to median,or 50%
chance,values.
Mean annual water yield increases with increasing elevation,and 1s affected
by topographic conditions and geographic locations.Water yield -elevation
relationships were calculated for little Sus1tna,Talkeetna,and Chulitna
Rivers,and are presented in Tables 9,10,and 11.Only very yeneral
estimates of water yield -elevation relationships were developed for other
rivers in the basin,and these are not included here.The percentage of total
water yield contributed by groundwater flow (and hence not measured by
streamflow gages)was not evaluated;however,it was estimated from site
conditions to be very small.
Construction of Maps
Mean annual·precipitation and mean annual water yield maps were developed
concurrently.Each map was necessary for developing the other,both because
insufficient data were available to develop each individually,and because the
-24 -
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2,823 sq.mi.in.divided by 61.9 sq.mi.=45.61 inches
Table 9.Mean Annual Water Yield from Little Sus1tna River
above gaging station no.15290000
:
Area ·Estimated Water Yield·Elevation Zone .sq.mi .·inches :square mile inches.··.·.
1000 to 2000 4.6 20 92
2000 to 3000 12.5 35 437
3000 to 4000 20.8 45 936
4000 to 5000 20.6 55 1,133
5000 to 6000 2.8 65 182
above 6000 0.6 70 42
----
Sunmat10ns 61.9 sq.mi.2,823 sq.mi.in.
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Comparison with Average Annual Water Yield:
Average annual water yield
Difference =1.07 inches =+2.4%error
-25 -
=44.54 inches
Table 10.Mean Annual Water Yield from Talkeetna River
above9a~1ng station no.15292700
:
Area ·Estimated Water Yield·Elevation Zone :sq.mi.:inches :square mile inches.·..·.
400 to 1000 92 13 1 t 196
1000 to 2000 284 15 4 t 260
2000 to 3000 428 20 8 t 560
3000 to 4000 483 24 11 t 592
4000 to 5000 265 34 9 t 010
5000 to 6000 282 42 11 t 844
6000 to 7000 139 50 6 t 950
7000 to 8000 32 60 1 t 920
above 8000 1 60 60
Summations 2 t006 sq.mL 55 t 392 sq.mi.in.
Comparison wHh Average 'Annual Water Yield:
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Average annual water yield
Difference =0.05 inches =-0.2%error
-26 -
=27.66 inches
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Tab.1e 11.Mean Annual Water Yield from Chulitna River
above gaging station no.15292400
:
Area :Estimated Water Yield
Elevation Zone .sq.mi.:inches :square mile inches.
:::
500 to 1000 216 25 5,400
1000 to 2000 454 32 14,528
2000 to 3000 462 39 18,018
3000 to 4000 616 47 28,952
4000 to 5000 315 53 16,695
5000 to 6000 223 61 13,603
6000 to 7000 117 68 7,956
7000 to 8000 70 75 5,250
8000 to 9000 48 82 3,936
9000 to 10000 31 85 2,635
above 10000 18 87 1,566
-
Summations 2,570 sq.m1.118,539 sq.mi.in.
Comparison with Average Annual Water Yield:
118,539 sq.mi.in.divided by 2,570 sq.mi.=46.12 inches
Average annual water yield =46.22 inches
Difference =0.1 inches =-0.2%error
-27 -
two phenomena are closely related.(As noted earlier.precipitation equals
water yield plus evapotranspiration;and water yield equals precipitation
minus evapotranspiration.)
Mean annual precipitation 1sohyets in lowland areas were drawn on the basis of
rain gage data.elevation.storm direction.and orographic effects.Data
seemed sufficient to make realistic precipitation estimates up to the edges of
adjoining foothills.Annual lowland water yield in inches was then computed
by subtracting annual evapotranspiration from annual precipitation.
From the foothills upward.and using computed lowland values as a starting
point.water yield 1s011nes were developed from streamflow data.Water yield
was assumed to be linearly related to elevation.In an iterative process.
1s011nes based on this assumed relationship were drawn on a map and compared
to measured water yields.The assumed relationship between yield and
elevation was then revised.and new 1s011nes drawn.until water yields
determined from the map equaled water yields measured at appropriate stream
gages.The completed water-yield map was then checked by plan1meter1ng
watershed areas between adjacent 1s011nes.computing runoff volume represented
by these 1s011nes.and comparing this value to measured runoff.Mean annual
precipitation 1sohyets were then drawn representing water yield plus estimated
evapotranspiration.
Both water yield and precipitation 1s011nes are generally related to contour
lines.but this relationship is not consistent because of localized
topographic.climatic.and orographic effects.Although these effects could
not be quantified.they were considered subjectively during delineation of
1s011nes.
Probable Accuracy of Estimates
Accuracy of mean annual precipitation and water yield estimates are limited by
the quantity and quality of available data.and by technical difficulties
involved in translating these data onto a map.For example.standard rain
gages are known to catch appreciably less than the average precipitation ~t
their locations.The discrepancy is greater during snowfall and on windy
sites.and varies from one situation to another;because of these variations.
no reliable correction factor is available.Mapped precipitation values for
the Susitna valley south of Petersv111e Road were based entirely on rain gage
data and are probably lower than actual values by as 'much as 15%.
Precipitation in mountainous areas was estimated only from watershed runoff
data.Precipitation estimates at any point are subject to substantial error
because distribution of runoff throughout the watershed was inferred.Values
shown for elevations above 8.000 feet are especially questionable.Only a
small portion of the basin exceeds 8.000 feet in elevation.and this area had
little influence in computations of runoff distribution.There is no apparent
basis for determining either magnitude or direction of errors in estimates.
but reported values are felt to be no greater than 25%above or below actual
precipitation values.
-28 -
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2.Soil s
Soils and water constitute soc1ety·s most important resources;both are
essential for life on earth.While the importance of water resources is
generally recognized,the importance of soils is often underrated.
Nonetheless,virtually all human act1v1t1es are to some degree involved with
plots of different s011s.Local soil conditions determine whether or not
farming,ranching,forestry,recreation,waste disposal,building and road
construction,wildlife management,and a host of other human activities are
physically feasible.
D1fferent kinds of soils develop in different locations.In any area,the
k1nds of s011s formed depend ~n local topography,climate,geology,hydrology,
organisms present,and length of soil formation.
The SCS regularly conducts soil surveys to map and analyze local soil
conditions.Soil surveys identify kinds of soils present,indicate their
locations 1n the landscape,and describe properties of each soil type (series
or phase)mapped.Properties described include:soil texture,structure,
porosity,plasticity,consistence,pH,organic matter content,depth,
permeability,and shrink-swell potential,among others.
In addition to s011 maps and data on soil properties,SCS surveys provide
land~use interpretations for different kinds of soils.These interpretations
are made using data on soil properties,supplemented with information on
slopes,local climate,susceptibility to flooding,etc.Interpretat10ns
1nd1cate how suitable each kind of mapped soil is for particular land uses.
Land uses considered include:production of locally adapted crops and
woodland products,recreation,grazing,res1dent1al settlement (e.g.,can
soils support bu11d1ng foundations or septic systems),and enhancement of
wildlife.In addition,soils are evaluated in terms of selected engineering
properties,e.g.,which soils provide sources for sand and gravel,which
provide material for construction of dikes,road beds,pond reservoirs,etc.
Because of the importance of soils to land-use planning,s011 surveys provided
1mportant information for land-use analyses conducted during the Sus1tna River
Basin study.Before the study began,three published soil surveys*described
soils on about 1,242,390 acres of the study area.As part of the Sus1tna
Basin inventories,additional s011 surveys are underway.Publication of the
Yentna Soil Survey,encompassing about 3,252,000 acres,is expected in the
near future.Procedures for conducting s011 surveys are described in detail
in the National Soils Handbook (USDA SCS,1983).
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Soil Survey -Sus1tna Valley Area,Alaska (USDA SCS,1973).
Soils of the Capital Relocat10n Site,Alaska (USDA SCS,1978).
-29 -
3.land Treatment and Agronomy
Because of the relatively low evapotranspiration rates in northern temperate
climates,crops in Alaska use less water than similar crops growing farther
south.Most of the water needs of northern crops are met by available
rainfall.Some crops on some so11s,however,do experience moisture stress,
and suffer consequent losses in quality and yields.F~r these crops,
appropriately applied irrigation is beneficial.
Several factors enter into determining when,how much,how,and if to
1rr1gate.Amount and timing of both precipitation and crop water needs,along
w1th soil capacity to store moisture,determine when and how much irrigation
1s needed.Topography.water availability,evaporation rate,and soil
infiltration (water-intake)rate determine how irrigation water should be
applied to a particular crop.Dollar values of increased crop production,
compared to costs of irrigation,determine whether or not irrigation makes
economic sense.
Considering these factors is important.Improperly timed or applied
irrigation may be of little value to crops and a waste of money,time,and
water.At worst,irrigating too much or at the wrong time may do considerable
damage,as when excessive irrigation degrades water quality,leaches soil
nutrients,reduces soil oxygen,or causes soil erosion.
The Susitna Basin study of land treatment and agronomy involved assessing the
effectiveness of irrigating specific crops in Alaska.During the assessment,
factors involved in answering the following questions were studied:
(1)Under what conditions will irrigation be beneficial?
(2)How much will crop yields be increased by irrigation?
(3)How much irrigation water should be applied?
(4)What 1rr1gat1on method w111 work best in a part1cu1ar s1tuat1on?
(5)What schedule should be used in applying irrigation?
(6)What problems may irrigation cause,and how can they be avoided?
Guidelines for answering these questions were compiled in:An Irrigation
Guide for Alaska (USDA SCS,in press).Users of the Guide can learn how to:
recognize symptoms of moisture stress in crop plants,determine both soil
moisture and net irrigation needs,and apply irrigation effectively.The
Guide also indicates the variety of irrigation needs in the basin (as well as
throughout other agricultural areas of Alaska).
-30 -
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Irrigation needs vary as a result of crop grown.sol1 cultivated.and local
climate.For example.a farmer growing potatoes in Talkeetna on a silt loam
soil with a 0.2 inch Awcll would basically never need to irrigate;since
natural moisture is adequate.irrigation does not improve his potato yields.
On the other hand.a farmer growing grass hay near Pt.McKenzie.also on silt
loam soil.would benefH by irrigating almost every year.In a wet£1 year
he would increase his hay yield by 11%if he added approximately 4.1 inches of
water during the growing season.In a dry year.he could improve his hay
yield by 43%if he added about 11.4 inches of irrigation water.(In both
cases.the efficiency of his irrigation system is assumed to be 65%.)
By comparing the,economic benefits of increased yields with the costs of
installing.maintaining.and operating an irrigation system.a farmer can
determine if irrigating would be cost effective.Table 12 indicates how
irrigation will improve yields of three crops in two locations in the basin.
The information used in preparing this table.such as AWC of agricultural
soils.net irrigation needs in the basin (and state).yield response of
different crops to irrigation.etc.were obtained from the Irrigation Guide.
4.Geology of the Sus1tna River Basin
Basin geological conditions were inventoried by the SCS using information
supplied by the u.s.Geological Survey (USGS)and the Division of Geological
and Geophysical Survey (DGGS)in the Department of Natural Resources.Because
no new data were collected.no separate geology report was published.The
synthesis.developed by Scott Sums10n for the SCS using existing data.is
presented below.
The geology of the Basin is relatively complex due to regional faulting and
folding of rocks in the Cook Inlet region.The region includes the Beluga.
Sus1tna.Yentna.and Cook Inlet Basins.bordered on the east by the Talkeetna
Mountains.on the west by the Aleutian Range.and on the north by the Alaska
Range.
1/AWC is the "Aval1ab1e water capacHy"of a sol1.It represents the
capacity of the soil to store water available for use by plants.The AWe is
usually expressed in linear depths of water per unit depth of soil.e.g .•
inches of water per inches of soil.
'f/For calculations in the Irrigation Guide.a "wet"season is defined as
wetter than 80%of the growing seasons in a particular area.based on
long-term climatological records.The wet season is also sometimes called the
20%chance season;that is.only 20%of the growing seasons will be as wet or
wetter.A "d ry "season is.therefore.the 80%chance season;that is 80%of
the growing seasons will be as wet or wetter.The "average."or 50%chance.
growing season is wetter than 50%and drier than 50%of the seasons on record.
-31 -
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The major drainage systems are the Sus1tna.Chulitna.Deshka.Yentna.
Skwentna.Beluga.Talkeetna.and Kahiltna Rivers.The lowlands contain oil.
gas.and coal bearing beds of Tertiary age.The region is generally mantled
by surficial deposits of glacial and fluvial origin.Exposed bedrock ranging
in age from Paleozoic through Tertiary has been identified.
The Paleozoic rocks are metamorphosed volcanic lavas and associated volcanic
rocks that occur primarily in the Talkeetna Mountains in the northeastern part
of the basin.Mineralized areas of copper.gold.silver.lead.and zinc occur
in these rocks.Triassic and Early Jurassic sandstones and shales interbedded
with volcanic flows also occur in the Talkeetna Mountains.
Mid Jurassic to late Cretaceous continental deposits of sandstone.shale.
limestone.and claystone occur in the Cook Inlet Basin.and have been
metamorphosed and mineralized in some areas of the Talkeetna Mountains.,
Associated mineralization occurs in the Alaska Range in the headwate~s of the
Skwentna River.
Tertiary rocks of the Kenai formation probably underlie a large portion of the
basin.but have been mapped only in the western area where coal beds outcrop.
and on the subsurface from oil wells south of the Castle Mountain Fault.
Abundant rock outcrops of igneous intrusives.ranging in age from Jurassic
through Tertiary.occur in some parts of the basin.mostly as large granitic
masses.They are found in mountainous areas to the west.north.and east.and
account for some of the metamorphism that has occurred.
At least 3.500 square miles of coal-bearing rocks occur in Tertiary deposits
located in the northern Cook Inlet lowlands.Beds of subb1tum1nous coal up to
30 feet thick lie in the Beluga Basin and adjacent areas.Other coal-bearing
areas include the Yentna.Sus1tna.and Cook Inlet Basins.
A wide variety of metallic minerals occur in lode.placer.and disseminated
deposits in the mountains and foothills.Elongated belts and localized areas
of these minerals are prevalent and can be related to basement faulting and
related intrusions.
Oil production within the Cook Inlet region began in 1957.Seven oil fields
and six gas fields are currently producing from the Kenai formation.
Potential oil and gas deposits occur in the Beluga and Yentna Basins.
Much of the basin is covered with glacial moraine material (It1ll").which in
many places covers bedrock with deposits at least 70 feet thick.I~is
difficult to map the underlying geology in ~uch areas except by seismic or
gravity surveys or by well logs.The greatest interest in Tertiary deposits
at this time focuses on the mineable coal deposits.The Tertiary beds have
not been satisfactory as aquifers for producing large quantities of water.
The basin contains several major fault systems associated with the Shel1kof
Trough.which occupies the gerteral area of Cook Inlet including the project
area.Faults associated with this Trough are:the Kn1k-Border Ranges fault
-33 -
on .the south side of Cook Inlet;'Bru1n Bay fault.Lake Clark fault.and Castle
Mountain fault on the north side of Cook Tnlet (but in the south of the study
area);and the SusHna and Denali faults on the north.AnumbeJof other"-
faults in thebasln have been mapped.but remain unnamed.GravHy data imply
that about 12.000 feet of high angle reverse displacement occurs on the north
side of the Castle Mountain fault.In addition.an estimated 10.000 feet of
displacement occurs toward the southeast 1n the Cook Inlet Basin.and 2.500
feet in the Beluga Bas1n.
The fault network is believed to run parallelur obliquely to the Shelikof
Trough.which developed in early Cenozoic time in southcentral Alaska.
Formational contacts are often offset by large northwestward-dipping.reverse
fault systems.asin the Castle Mountain -Lake Clark fault and Bruin Bay
systems.There are also indications of hor1zontal displacement and rotat10nal
and translational deformation caused by oblique stress.These tectonic
movements have resulted in a complex basement rock complex and subsequent
variability in thickness of Tertiary deposits.
The active Aleutian volcanic arc ends west of the basin at Mt.Spurr volcano.
Seismic discontinuity implies there is a hinge zone along the Yentna -Beluga
Mountain front between the northern McKinley block.which dips northward more
steeply than the Kenai block south of Cook Inlet.A subduction zone of the
Pacific p,late is indicated along the Aleutian trench and the Kenai block.
Mt.Spurr has potential for geothermal development.but difficulties are
inherent in developing geothermal resources of an active volcano located near
deep fault zones.'
5.Land Cover (Vegetation)
The objective of the land cover (vegetation)inventory was to map and
quantitatively describe plant communities (and other land cover types)
throughout the basin.Land cover maps.once developed and automated.were
used to a~sess vegetation-related resources in the basin.such as timber.
range.wildlife habitats.and recreational areas.These assessments were.in
turn.,used by the state and borough in making land-use decisions.
Methods used to develop land cover maps and to conduct field sampling are
briefly described below.Detailed field procedures used to inventory basin
vegetation types are described in:Preliminary Field Procedures for the
Cooperative Vegetation Inventory of the Susitna River Basin.Alaska (USFS-PNW.
1979).
Detailed descriptions of each mapped plant community (vegetation cover type).
based on field data.are presented in Resource Statistics for the Susitna
River Basin (USDA in preparation).
Land cover (vegetation)mapping was conducted using aerial photographs in
conjunction with ground sampling.Initial cover-type mapping was performed on
false-colur infrared photography that had been enlarged from a scale of
1:120.000 to 1:60.000.On each air photo.visibly separable land areas
-34 -
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(polygons)were outlined.each consisting of a relatively homogeneous parcel
of land at least 10 acres in size and 165 feet in width.As distinguishable
polygons were outlined.each was labeled with a primary code denoting the
specific land or vegetation cover typel/contained in that polygon.In
certain instances.secondary and tertiary'codes were used for polygons in
which cover types occurred as comp1exesf!or assoc1at1ons~/that were
impossible to map separately.Once completed.all land cover maps were
rectified ("edge-matched"and scaled)to standard USGS maps at a scale of
1:63.360 and then digitized for use in computer modeling.Land cover
categories used for mapping are shown on Table 13.
Statistical analysis of land cover types was accomplished using a double
sampling method involving photo interpretation and ground sampling.Primary
photo interpretation points were selected systematically using a grid system.
The number of field plots to be sampled for each cover type was determined in
part by:the number of photo points (grid intersections)occurring in that
cover type;acceptable sampling error;estimates of cover-type variance based
on previously completed plots;and cost.Ground sampling was done on 485
plots selected from 11.246 primary photo points.
Ground plots were sampled by multi-disciplinary crews.Use of a helicopter
permitted field crews to precisely 10cate~nd then access selected grid
intersection points.Plots were permanently monumented for future inventory.
and resources were measured using a 10-po1nt sample pattern.This pattern
provides an inventory of a 5-acre plot on the basis of measurements made at 10
equidistant subsamp1e points.All 10 points are located within the same
vegetation type as the initial grid intersection point.
Data were collected on tree.shrub.understory.and ground cover vegetative
1ayer~.as wells as on soils and wildlife use and habitat parameters.On
forested points.measurements were made of tr~e diameter.height.age.radial
growth~and tree class.These data were compiled and analyzed to obtain tree
volumes.growth.and mortality.At each of the 10 points.ground cover.total
canopy cover.and vegetation under 4.5 feet in height were measured using a
2x2 foot sampling plot.Shrubs over 4.5 feet in height were sampled at 2 of
the 10 points using a 10x10 foot plot.Cover.height.and annual production
were estimated for each plant species in each plot.
1/Type -(Land Cover Type)-one of 36 categories of vegetation defined by
plant species composition.canopy cover.height.and/or age.In non-vegetated
types.one of 10 categories.including cultural influence.mud.rock.snow.
glaciers.lakes and streams.-
£/Complex - a mosaic of distinctive vegetation types.Each type is
d1st1ngu1shab1e but too small to map separately.
~/Association - a mixture of vegetative growth forms.such as grasses.
shrubs.trees.etc .•that occur together naturally.but not as distinct types;
typically as small visible pockets of undergrowth in open forests .
-35 -
Table 13.Land Cover Mapplng Unlts
VEGETATED
FOREST AND WOODLAND -
more than 10%Crown Cover
NON-FOREST -less
than 10%Crown Cover
NON-VEGETATED
40 ac.
10 ac.-40 ac.
and rlvers
-660 ft.wlde
1/8 ml1e wlde
(660 ft.)
OTHER
70-Cultural Influence
71-Tyonek T1mber Sale
BARREN
80-mud flats
81-rock
WATER
91-lakes
92-lakes
96-streams
165 ft.
97-rlver
PERMANENT SNOW
AND ICE
82-snowfleld
.83-g1acler
SALT WATER WETLANDS
50-grassland
51-low shrub
52-tlda1 marsh
LOW SHRUB
62-wl11ow-resin birch
TALL SHRUB
60-a1der
61-alder-w111ow
(streamside veg.)
63-GRASSLAND
TUNDRA
64-sedge-grass
65-herbaceous
66-shrub
67-mat and cush10n
CONIFEROUS FOREST
WHITE SPRUCE
31-short stands 30 ft:
33-ta11 stands 30 ft.
OPEN FOREST-WOODLAND
10-50%crown cover
BLACK SPRUCE
43-short stands 10 ft.
DECIDUOUS FOREST
Open Dec1duous-
Open Mlxed
32-med1um-aged stands
40-80 yrs.
34-o1d stands 80 yrs.
CLOSED FOREST
50%crown cover
CONIFEROUS FOREST
WHITE SPRUCE
21-short stands 30 ft.
25-tall stands 30 ft.
DECIDUOUS FOREST
Closed Declduous-
Closed Mixed
22-young stands 40 yrs.
24-medlum-aged stands
20-80 yrs.
26-o1d stands 80 yrs.
BLACK SPRUCE
41-short stands 10 ft.
42-tall stands 10 ft.
MOUNTAIN HEMLOCK
45-short stands 30 ft.
46-tall stands 30 ft.
COTTONWOOD
27-young stands
40 yrs.
28-med1um-aged stands
40-100 yrs.
29-o1d stands 100 yrs.
COTTONWOOD
35-med1um-aged stands
40-100 yrs.
36-o1d stands 100 yrs.
FRESH WATER WETLANDS
68-sphagnum bog
69-sphagnum-shrub bog
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The primary s~11 type was identified and a description of that soil was made
at each initial sample point;additional soil descriptions were prepared if a
significant change in soils,topography,or vegetation occurred within the
5-acre plot.
6.Recreation
Existing recreational resources in the basin were inventoried and mapped by
DNR-D1v1s1on of Parks under an agreement with the USDA.The results of that
inventory are presented in Recreation Atlas -Willow-Talkeetna Basin (DNR,
1980).In addition,the SCS analyzed selected economic impacts of a wide
range of basin recreational acttvit1es,and assisted the Alaska Department of
Fish and Game (ADF&G)in analyzing economic impacts of basin sport fishing and
hunting.The SCS analysis is discussed later in this report (Section E).The
ADF&G analyses*are published in:Fish and Wildlife Resources Element for the
Susitna Area Planning Study (ADF&G Habitat Division,1984).
7.Archeological,Historical,and Cultural Resources
Three Sus1tna Basin cultural resource inventories and assessments**were
prepared by ALASKARCTIC under contract to the USDA:
1)Cultural Resource Assessment:Talkeetna-Lower Sus1tna River Basin,
Southcentral Alaska (G.Bacon et al.,1982)
2)Cultural Resource Assessment:Talkeetna-Lower ~us1tna River Basin,
Southcentral Alaska (supplemental report)(G.Bacon and T.Cole,1982)and
3)Cultural Resource Assessment:Beluga Study Area.Southcentral Alaska
(G.Bacon et al.,1982).
These three assessments,plus a previous assessment conducted by D.R.Reger in
the Willow Subbasin,have been published in a single document by the SCS:
Sus1tna River Basin Study Cultural Resource Assessment of
W1110w-Talkeetna-Beluga Areas (USDA,1983).Highlights of the Lower Sus1tna
and Beluga Assessments are summarized below.
*Appendix A.Sus1tna Area Plan.Human Use and Economic Effects--Sport
Fishing (S.H.Burgess,1983).
Appendix B.An Economic Analysis of Moose.Caribou.Sheep.Bear and
Waterfowl Hunting in the Sus1tna Basin (S.H.Burgess,1983).
**Because the Alaska Power Authority is conducting a detailed environmental
assessment of the Upper Sus1tna area for the potential Sus1tna River
hydroelectric project,no data were collected in the Upper Sus1tna Basin
during this study.
-37 -
Data for the Lower Sus1tna and Beluga cultural assessments were compiled from
literature review and personal interviews.supported by limited field work.
These data were generally grouped into three periods:prehistoric.
ethnoh1stor1c.and historic.
The prehistoric period predates the period covered by written record~or
cultural memory.Before the Sus1tna study.the prehistory of the study area
was completely undocumented.The study synthesized available data;but no new
data were uncovered.Knowledge of study area prehistory continues to be
extrapolated from information gathered in adjacent areas.particularly in
Interior Alaska.There.four prehistoric periods are distinguished:1)the
Tundra Period (ending circa 8.000 yrs Before Present).2)the Early Taiga
Period (circa 8.000 yrs to 4.500 yrs BP).3)the Late Taiga Period (circa
4.500 yrs BP to AD 500).and 4)an Athapaskan Per,od (from approximately AD
500 to AD 1900).The prehistoric Athapaskan Period grades into the
ethnoh1stor1c period described below.The ethnoh1stor1c period is.in turn.
followed by the historic Recent Period,extending from about AD 1900 to the
present.
Although no prehistoric archeological sites are known in the study area,the
potential for such sites to be located appears to be quite high.The
Talkeetna area,in particular,appears to be rich enough in resources to have
attracted relatively dense settlement during prehistoric times,while much of
the Beluga study area would appear to have been a seasonal resource zone for
permanent Tana1na (Dena '1na)Athapaskan settlements located nearer to the
Susitna River.Systematic field surveys are very likely to uncover
prehistoric sites.particularly 'near rivers used by anadromous fishes,shores
of lakes and ponds,margins of lowland wetlands where furbearers and migratory
waterfowl are abundant,and areas through which large mammals would be
naturally funneled as they moved from wintering to summer grounds.In
addition,several of the "Dena '1na place names"(see below)are associated
with sites that should possess some indication of past activity.Once
investigated.specific sites (identified and mapped in the Talkeetna report)
may add a great deal to current understanding of the Tana1na in the late
prehistoric and early ethnoh1stor1c periods.
Ethnoh1stor1c period bridges the gap between poorly documented Alaska Native
prehistory and the recent history of western civilization,and is considered
to extend in time from the limit of cultural memory to the present day.
During modern times.Alaskan ethnoh1story becomes interwoven with the history
of white settlers because,in Alaska.many native populations lived
essentially aboriginal life styles well into the 20th century.Ethnoh1stor1c
data indicate the existence of a rich aboriginal history in the study area,
only a fraction of which has so far been recorded.Most of the ethnoh1stor1c
data compiled for the Sus1tna study are contained in the annotated list of
Dena '1na Place Names.The list of place names summarizes ethnogeograph1c data
on habitation of the Sus1tna River drainage by the Upper Inlet Dena '1na
(Tana1na)Athapaskans before contact by "white men,"e.g.,where the Dena '1na
hunted,fished,camped,settled,etc.The data presented in the list are
derived from interviews and tape recordings of Dena'1na speakers knowledgeable
about Dena '1na history and folklore.Considerable additional data ~n the form
-38 -
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of recordings of folklore.music.and history.as well as additional field
notes.are available.but lack of time precluded all but the most minimal
references to these sources in the Sus1tna study reports.Annotations about
geographical locations included in the published list are indexed mainly to
tape recordings from the archive of Dena l 1na language tapes housed at the
Alaska Native language Center.University of Alaska.Fairbanks.The bulk of
recordings in this archive have not yet been transcribed or published.When
they are.a much fuller picture of the aboriginal occupation of Cook Inlet
will emerge.The list of Dena l 1na Place Names suggested some areas to cover
during the brief field survey conducted in the Talkeetna Subbasin.but field
search for ethnoh1stor1c sites indicated they will be found only through
careful and systematic archeological survey.
Information on historic use of the -study area by white men is relatively
abundant.Material summarized in the Sus1tna study reports concentrated on
the major activities taking place in the study area from the turn of the
century to the present.including mining.trapping.hunting.trading.and the
use and expansion of roads and trails.locations of historic interest in the
Talkeetna and Beluga Subbasins were compiled in a list of study area
historical sites.The list identifies which sites are already listed in the
Alaska Heritage Resource Survey (AHRS)file.maintained by the Office of
History and Archaeology.Alaska Division of Parks.and which sites will be
nominated to the AHRS file as a result of the Sus1tnastudY.In addition.
many places in the study area appear to meet minimal eligibility requirements
for nomination to the National Register of Historic Places.either as sites or
as districts.In general.historic per~od sites appear relatively easy to
find.but many have decayed with disuse and are no longer visible.
8.Fish.Wildlife and Wetlands
a.Fish and Wildlife
The fish and wildlife inventory work in the basin consisted of two main
activities:1)"modeling"the relative fish and wildlife values of basin
lands.and 2)assisting the ADF&G in developing a methodology for creating
fish and wild1 He "element maps.lIThe USDA SCS prepared a fish and w11d1 He
report describing these two activities and summarizing selected data on:
1)species present in the basin.2)acreages in the basin of particular kinds
of habitats.and 3)human uses of basin fish and wildlife resources.
Highlights of this report.Identifying Wildlife lands:Fish and Wildlife
Analyses for the Sus1tna River Basin Study (USDA SCS.1984),are summarized
below.
In the modeling analyses,basin habitats were evaluated in terms of:1)their
relative ability to provide food and/or cover seasonally to selected wildlife
species (five species in the Willow Subbas1n--moose.snowshoe hare.red
squirrel,willow ptarmigan,and spruce grouse;and one species,moose.in the
Talkeetna.Beluga,and Upper Sus1tna Subbasins);2)their relative ability to
support a variety of wildlife species ("species diversity");and 3)their
relative abundance within the basin ("habitat scarcity").Computer maps were
-39 -
produced d1splay1ng the results of each evaluat10n.Tables 14 and 15 prov1de,
respectively,est1mates of big game populat10ns1n the bas1n,and examples of
"preferred"habitats for selected bas1n mammals.Table 16 summarizes
ava11ab111ty of some of these hab1tats 1n terms of acres and
percent-of-subbas1n.
Results of each mode11ng analys1s were 1ntegrated 1nto one "hab1tat synthes1s
model"us1ng steps summar1zed 1n Table 17.Results of the synthes1s model
were then comb1ned w1th ava11able ADF&G data to create f1sh and w11d11fe
element maps for use by state planners.Element maps out11ne a system of
bas1n lands that 1f managed for f1sh and w11d11fe would be h1ghly su1table to
ma1nta1n these resources and the1r human uses.The system 1s des1gned to
encompass:1)lands prov1d1ng hab1tats for 1mportant spec1es,such as moose,
black bear,brown bear,and salmon,2)lands support1ng hab1tats used by a
large var1ety of w11d11fe spec1es,3)lands that are relat1vely scarce 1n the
bas1n or sens1t1ve to d1sturbance,4)lands serv1ng as 1mportant access routes
or harvest areas for human users of f1sh and w1ld11fe,5)lands support1ng
valuable wetlands,and 6)"phys10graph1c 11nkages"(such as networks of water
bod1es,systems of wetlands,an1mal m1grat10n routes)that 1nterconnect f1sh
and w1ld11fe hab1tats and ma1nta1n the1r ecolog1cal processes.In add1t10n,
f1sh and w1ld11fe element maps subd1v1de 1dent1f1ed f1sh and w11d11fe lands
1nto four categor1es on the bas1s of general management and enhancement
act1v1t1es feas1b1e 1n d1fferent areas.Data used and steps 1nvolved 1n
creat1ng f1sh and w11d11fe element maps are descr1bed 1n the SCS f1sh and
w11d11fe report.Add1t10na1 data on bas1n f1sh and w11d11fe and hab1tat
resources are prov1ded 1n:F1sh and W11d11fe Resources Element for the
Sus1tna Area P1ann1ng StUdy (ADF&G Hab1tat D1v1s10n,1984)
b.Wetlands Mapp1ng 1n the Sus1tna R1ver Bas1n
The Sus1tna Bas1n wetlands 1nventory resulted 1n preparat10n and automat10n of
wetlands maps that could be used 1n mak1ng land-use dec1s10ns.These wetlands
maps were used 1n 1dent1fy1ng key f1sh and w1ld11fe lands (see d1scuss10n
above),and 1n mak1ng other land-use dec1s10ns,e.g.,1n determ1n1ng whether
or not lands would be su1tab1e for agr1cu1ture or settlement (see Sus1tna Area
Plan.Pub11c Rev1ew Draft--Summary [DNR,1984]).Because no separate wr1te-up
accompan1es the wetland maps,def1n1t10ns and methods used 1n mapp1ng bas1n
wetlands are descr1bed below.
-40 -
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Table 14.Big game population estimates for the
Sus1tna River Bas1n/Matanuska-Sus1tna Borough
Estimated :Estimated
Borough :%of State
Species :Population l!:Population f!:Preferred Habitats
:
moose 49,000 25-50%Young forests,especially deciduous
and mixed forests;low and tall
shrublands with willow,birch,
aspen,poplar,cottonwood,alder,
lowbush cranberry,and other woody
browse;freshwater wetlands,
including muskegs,bogs,marshes;
forested and shrubby stream and
river valleys
brown bear 1,000 10-20%open tundra and grasslands;but
also uses a wide variety of shrub
and forest habitats,especially if
they are relatively open
black bear 2,000 10%forests and woodlands;preferred
areas seem to be semi-open forested
areas with understory vegetation of
fruit-bearing shrubs,herbs,lush
grasses.and succulent forbs
Dall sheep 6,000-12-16%steep grasslands and tundra in
8;000 alpine zone characterized by
cliffs,deep canyons,rock
outcrops,and other types of
"escape terra1n"
"mountain goat 300 --alpine and subalpine areas in the
Talkeetna and Chugach Mountains
with grasses,sedges,and forbs;in
winter,prefers rocky wind-blown
ridges where forage remains
accessible
wolf 800-1,000 8-13%all habitats in which preferred
prey species (e.g.,moose,caribou,
small game.etc.)are available
l!Source:ADF&G.1982.Fish andwlldlHe resource and public use
information for Matanuska-Sus1tna-Beluga study area.ADF&G,Anchorage.43 pp.
2/Source:derived from Rearden (ed).,1981.Alaska mammals.Alaska
Geographic 8(2).
-41 -
0
Table 15.Preferred habitats for selected Sus1tna Basin mammals
0-'"'"tU C:-...n0en0....-....;.c
'i .c '"u en :)...'1:l U
'1:l -...-CIICII'1:l 0 .Q '"'1:l
'"CII .....-c jJ0'"'1:l C tU....0 -c -'"u ....'1:l tU '"'1:l ..
U CII -C tU...'"......tU e
0 ...0 CII ....
0 ....'1:l ...;c u .......:-CII
CII C CII tU 0 :-:)nQ.CII ...'1:l I ....0
.0 ..---Q.......0 ---~---U't __....--'---CII-0 tU .Q ----.--------Ut CII ---u-C I :):-.Q ..tU
'"CII '"...I :)tU .Qen..'"Q.'".Q .c '"...:-...
I-'"..0 ..:)'".Q .c .c CII
C CII '"-'"...:)'"'".c
I-...CII CII .c .......CII -[J-0 ...'"...'".....c :-...-ClCl ....0 ..0 tU '"0 ....tU tU'"
C ....'"....................'"::z::'"CII ....:-'"'"'1:l '1:ltU
:)'".....tU ..0 ..:)'1:l C C ...
Cl 0 :)0 c ..c ....c 0 c :):)en.......0 ....tU tU tU CII tU ....I
I-CII :)-'1:l -'1:l -U ....CII
U ....'1:l '1:l ...C ...C ...tU '".Q ...en [J....- -
CII tU tU tU tU tU .Q '":)CII'1:l
-l C U >C Q.....Q.....Q....tU ....cCII....0 CII --Q.-Q.-CII ....c ..'"SELECTED SPECIES en u Cl z:=======::z::~en Cl
l.masked shrew X X X X X X X X X X X X 02.pika alpine X
3.snowshoe hare X X X X X X X X w/cover X
4.hoary marmot alpine X 05.arctic ground squirrel alpine X
6.red squirrel -X X X
7.northern flying squirrel X X X 08.beaver X X X
9.northern red-backed vole X X X X X X X X X X X
10.muskrat X X X X 8-ll.northern bog lemming ----mo1st----X X X X moist X
12.meadow jumping mouse ----open-----X X X.X moist
13.porcupine X X X X 014.coyote X X X X X X X X X X X X
15.grey wolf X X X X X X X X X X X X
16.red fox ----open-----X X X X X X X X X 017~'black bear X X X X
X X X X
X
18.brown bear ----open-----X X X X X X X X
19.marten X X X B20.short-tailed weasel ----open-----X X X w/cover X X
2l.mink ----edges----X X X X
22.wolverine X X X X X X X X
X X U23.river otter X X X X
24.lynx X X X X X X X X X X
25.moose X X X X X X X X X
w/cover X []26.caribou X X X X alpine X X
27.mountain goat --in winter--X spring alpine X X
28.Dall sheep near spring alpine X X Ctreel1ne
*-Riparian-habitats are defined as those plant commun1t1es near enough to r1vers,streams,ponds,or Clakesforthesewaterbodiestobereadilyaccess1bletomammalspec1es1nques"t10n.This distance
varies w1th s1ze and mob1l1ty of part1cular spec1es.
E
~Il::T-::::J Ir':"":'"'J c:TJ C"':"'J ["".,,,J ~t:r:!!1 tl:ll!l,!~,:J t:C'"'l r-::l t",j"J rJ r---1 r=::l r;:r""'j r--1 r::J r""'J
Table 16.Sunmary of ,selected plant cOllJllunHy (wl1dlHe habHat)acreages
VEGETATION TYPES •
(SCS map codes)
II
WILLOW
:"ofacres:SUbbastn
SUB BAS INS
TALKEETNA UPPER SUSITNA
: "of::"ofacres:SUbbastn:acres :Subbastn
BElUGA
"ofacres:SubbasIn
1..Open mhed fores t
(32,34)
2.Closed mIxed forest
(24.26)
3.Open conIfer forest
(31,33)
4.Closed conIfer forest
(21,25.41,42)
5.Open decIduous forest
(35,36)
6.Closed decIduous forest
(22,21,28.29 )
1.Tall rtpartan shrub-
alder,wIllow (61)
216,010 28.48
112,010 11.15
(Includes 43)
3,390 .35
51,160 2.49 11,600 .61 155,610 10.14
628,170 21.11 31,120 2.00 203,040 14.00
61,010 2.89 20,400 1.08 5,210 .36
153,850 6.63 11 ,240 .91 49,410 3.41
1,140 .08 ,£1 Y 5,110 .40
12.880 .56 2,120 .14 6,150 .42
136,280 5.88 20,680 1.09 59,420 4.10
49,610 5.12
8.Tall shrubs-alder 481,100 21.03 342,440 18.12 435,000 29.99
(60)
g:--T()w sllrubs-wlffow,------l2-,"130---1.31 13.250--.51 105,920 5.61 16-;280 1.12
resIn bIrch (62)(1ncludes (6)
10.SaHwaterwetlands-23,310 2.41 11,380 .49 ~~lr--O 18,940 1.30
grass,sedge,shrub
(50,51,52)n.81ack spruce-forests.(43 tncluded 528,010 22.11 ---s,400--.29 218,150 15.04
muskegs,sphagnum bogs above:68,69
_(43,68,69)not totaled)
12.Grass land (63)194,580 20,01 29,130 1.26 1,120 .06 25,650 1.11
13.Tundra 3F 145,150 14.98 -68,160 2.94 1,106,960 58.58 160,250 '-11.05
(64.65,66,61)(excludes 66)
lotal vegetated acres 876,910 90.41 2,196,040 94.69 1,612,200 88.49 1,359,080 93.11
II 11
14.water-lakes,streams 99,830 4.30 8,280 .44 33,990 2.34
(91,92,96,91)
92,360 II 9.53 11
15.Non-vegetated 23,380 1.01 209,240 11.01 51,350 3.95
(10,80,81,82,83)
Total acres 969,210 100.00 2,319,250 100.00 1,889,120 100.00 1,450,420 100.00
*Vegetatton types are descrIbed tn detaIl In:Resource Stattstlcs for the Susltna RIver BasIn (USDA tn progress).
11 W1110w SubbasIn plant cOllJllunHy classes are not dIrectly comparable to classes tn other SUbbasIns,acreages presented here are therefore
rough totals.
,£1 MInImum mappIng unH In this subbastn was 40 acres rather than 10 acres,therefore,plant cOllJllunttlesoccurrlngln small scattered parcels
(polygons)do not appear on the map.
~/In WIllow Subbasin,shrub tundra (SCS (6)Is combtned with low shrub acreage (SCS 62).
InstructIons for each step
Table 17.Sunvnary of InstructIons for habitat synthesis model
SCS vegetatIon codes :Total acres (%of vegetated acres)*
Included by each step :In SubbasIn Included by each s~
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:
map all "very scarce"and "scarce"
habItats havIng "hIgh spec1es d1vers1ty"
plus all "very scarce"habItats hav\ng
"moderate specIes dIversIty"
map all "open mIxed forests"and "tall
alder-wIllow r1par1an shrublands"1f not
prevIously mapped and 1f not "abundant"
map stream and r1ver corrIdors
map all "shrub tundra"and "low shrub
wIllow-resIn bIrch"If not prevIously
mapped and If not "abundant"
map selected freshwater wetlands not
yet mapped
Totals
.
Talkeelna-8e1uga
SUbbasIn
31,33,35,36,
50, 51,52,62;
22,21,28,29,
43,51,63
32,34,61
stream corrIdor
portions of 21,
24, 25,26,41,
42,60,64, 65,
66,67,68,69
66
SCS wetland codes
2,3,6
Upper Susltna
Subbas1n
24,26,31,32,
33,34,61;
21, 22,25, 27, 28,
29,41,42,43,63,
68,69
1nc1uded by
step 1
stream corrIdor
port10ns of 60,
64,65,66,67
62,66
SCS wetland codes
2,3,6
Talkeetna-Beluga
SubbasIn
225,784 (6.35%)
409,194 (11.51%)
not computer
mapped,
(not computed)
17,470 (0.49%)
not computer
mapped,
(not computed)
652,448 (18.35%)
Upper Susltna
SubbasIn
103,342(6.18%)
Included by
step 1
not computer
mapped,
(not computed)
93,810 (5.61%)
not computer
mapped,
(not computed)
197,152 (11.79%)
*94.3%of the Talkeetna-Beluga SubbasIn Is vegetated,
88.5%of the Upper Susltna SubbasIn Is vegetated.
rn c:1 c:J ern L...._J tLL]LH"..,Jill CJ rtrJ c=J [...1 c:=:J C"l l ___J L_J l___J c=J L--J C=:J
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The wetlands inventory conducted for the Sus1tna Basin study represented a
cooperative federal-state effort to identify.classify.and map wetlands in
the basin.The following definition of wetlands was used:
"Wetlands are lands where saturation with water is the dominant factor
determining the nature of soil development and the types of plant and
animal communities living in the soil and on its surface.The single
feature that most wetlands share is soil or substrate that is at least
periodically saturated with or covered by water."11
Following this general definition.land areas fitting into one of the
following two categories were identified and mapped as wetlands:
land areas which.at least periodically.support predominantly
hydrophytesll and in which the substrate is predominantly very poorly
drained or undrained hydric so11~/;or
land areas which are located within an active flood p1a1n!/;regardless
of vegetation or soil conditions.
As indicated above.non-floodplain wetlands were identified and mapped by
combining data on soil drainage and vegetation types.Both data sets were
combined because.in Alaska.lists of hydric soils and lists of hydrophyt1c
plants are too preliminary to be used separate1y.~1 Figure 5 presents the
plant community-soil matrix used to identify vegetated basin wetlands.
11 Coward1n.l.M.et a1 .•1979.Classification of wetlands and deepwater
habitats of the United States.USFWS-OBS.Washington.D.C.103 pp.This
definition corresponds closely to the legal definition of wetlands used by the
U.S.Army Corps of Engineers during its "404 11 wetland permit review
activities:"'Wet1ands l means those areas that are inundated or saturated by
surface or ground water at a frequency and duration sufficient to support.and
that under normal circumstances do support.a prevalence of vegetation
typically adapted for life in saturated soil conditions.Wetlands generally
include swamps.marshes.bogs.and similar areas.11 (33 U.S.C.323.2(c))
II hydrophyte:any plant growing in water or on a substrate that is at least
periodically deficient in oxygen as a result of excessive water content.
~I hydric soil:soil that is wet long enough to periodically produce
anaerobic conditions.thereby influencing the growth of plants.
!I active flood plain:the flood-prone lowlands and relatively flat areas
adjoining inland and coastal waters including contiguous wetlands and flood
plain areas of offshore islands;this will include.at a minimum.that area
subject to a 1%or greater chance of flooding in any given year (100-year
flood plain).
~I In Coward1 n et a 1.(op.c H.).the presence of eHher hydr 1c soil s or
hydrophyt1c vegetation is sufficient to identify an area as a wetland.
-45 -
i SOILS DRAI/'f~I
~
SHORTClR l'ALL WHITE SPllCle!--f VERY POORLY DllAII'fI!D l'OR£STl!i)/'f1!!DLE·LUt.VI!O EVI!RQREEI'f ISHORTCLOSI!D IIl.AC:J(SPRlICE
-4 i'oRl!ST DECIOCIOClS""XI!D f'ORUT H VI!RY POORLY DRAlnl!DYOClftGCLOSl!DCOTTOt'lWClOO FOREST!DI'fI!EDLE LUt.VI!D I!VERCREEn,
Al'fDBROADLEAVI!D.DI!CIOClOClS
"'~UIl!lIU'lDOLDC01TOIlWClOO --t VERT.POORLY DRAlI'lI!D
SHOIn'OPEI'IIILACK SPRClC!~VERY POOIILYDRAII'lI!D SCRCl8ISHIItIBI'fEI!DLE LEAVED evl!RGRI!En
I POORLY DRA'I'lI!D POT!I'lTIAL PALClSTRII'lI!WI!TLAI'fD I-
/
LOWSHllCIa I-WILLOW RI!SII'lBlIlOt H POORLYDRAIftl!O
-4 SHIlCI8LAI'lD
TALLSHRCla I--ALDER H VI!RY POORLY DRA'I'fED SCRClBlSHRClIlIIROAD L!AVI!DDECJOClOClSALDI!R·W'LLOW:
rl POORLYDRAII'fI!D
H VI!RY POORLY DRAlI'fI!D
r-I SHRUB I-
1-1 HAT AI'lOCClSHIOI'f
I VI!CETAnort I-~.TUl'fDRA POOllLY ORAIftI!D I-1-1 HERIIACI!IOClS :!l!:iVERY POORLY DRAlnl!O t-"'\..
y S1!DGI!-G1lASS
POOllLY ORAII'fI!D r 1-~CAAS5l.AI'lD ClRASSLAI'fD
VERY POORLY ORAlI'lED t-H I!"'I!RClI!l'lT PERSISTAI'fT I
POOllLYDRAlI'lI!D t-
VERT POORLY DRA'I'fED t-.SPHACl"U'"IlOCl
rl I'RI!SHWATER POORLY DRAlI'lI!D
SPHAClriu ...·SHIlCIIlIlOCl
VERY POORLY ORAII'l!O
.
AQUATIC I-POORLYDRA'"I!D II'fTERnO/lL SCRUII/SHRUII
BROAD LEAVED DI!CJOUOUS
VI!RY POORLY DRAII'lI!D
r-I LOWSHIlUII
Y SALTWATER I-I-rl POORLY ORAI"EO t-
H ClRASSLAI'fD -;'mEllnDAL £llilERGEI'fT PERS'STAI'fT
i-i nOAL ...ARSH I-y VERY POORLY OIlAlI'lI!D t-
lJ
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LOWER PEREI'lPl'AL
A"'O"'ClDf'LAT
WETLAl'fD TYPE
U"'I'lETIC AI'lDUTTORAL
UPPER PEREI'fI'lIAL
Ul'fCOI'lSOLJI)/ITED IlOTTO ...
UI'lCO"SOLIDATED BOTTO""
II'lTERTIDAL CONSOLIDATED S'IORE
L!SS THAI'1&5 FT.
J65toHOFT.
"'UDf'LATS
ACTIVE FLOOD PLAlI'lS
LAKES 'Oto4OACRES
CREATERTHAl'fHOFT.
LAKES CREATl!RTHAI'l 40 ACRI!S
II'fTERPRETED MAPSBASEDATA
[j
Figure 5.Wetland Identification Matrix E
""""1
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.,
.=1
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Ident1f1ed wetlands were c1ass1f1ed accord1ng to the system developed by the
USF&WS for the1r on-g01ng Nat10na1Wet1ands Inventory Program.Table 18
presents USF&WS vegetated wetland classes correspond1ng to thevar10us
vegetat10n-s011 and vegetat10n-f100d p1a1n classes d1sp1ayed 1n F1gure 5.
Acres and percent-of-subbas1n covered by each of these classes 1n the
Talkeetna and Beluga Subbas1ns are presented 1n Table 19 .
Two 11m1tat10ns of th1s wetland 1dent1f1cat10n and mapp1ng process should be
noted.F1rst,the m1n1mum map un1t,or smallest area resolvable on wetland
maps,1s 10 acres.As a result,wetland areas less than 10 acres 1n s1zeare
not accurately de11neated:wetlands 5 acres or larger may appear as 10-acre
wetlands,wh11e wetlands smaller than 5 acres may not show on the map.
Second,as F1gure 5 1nd1cates,wetlands occas10na11y occur on "poorly"dra1ned
s011s;and wetlands on these s011s may not all be mapped.For example,
topograph1c depress10ns can conta1n wetlands w1th "poorly"rather than "very
poorly"dra1ned s011s.F1e1d check1ng of poorly dra1ned topograph1c
depress10ns would be necessary to determ1ne whether or not they produce
wetland cond1t10ns .
9.Flood P1a1ns
F1ve flood p1a1nmanagement stud1es were prepared dur1ng the Sus1tna R1ver
Bas1n study:
1)Flood Hazard Study,Kroto.Rab1deux.Trapper.and Peters Creeks
(USDA,1982)
2)Flood Hazard Study.196 M11e.Caswell.Sheep.Goose.Montana.Answer.
and B1rch Creeks and Tr1butar1es (USDA,1981)
3)Flood Hazard Study.Troublesome.Byers.and Honolulu Creeks;East and
M1dd1e Forks of the Chu11tna R1ver (USDA.1981)
4)Flood P1a1n Management Study.Beluga Subbas1n Streams (USDA,1982)
5)Flood P1a1n Management Study.Kashw1tna R1ver;Was111a.Cottonwood.
and luc11e Creeks (USDA,1982).
General methods used and results obta1ned dur1ng these stud1es are summar1zed
below.
Flood p1a1n stud1es were completed at levels of 1ntens1ty commensurate w1th
ant1c1pated pressures for development.F100d-hazard-re1ated topograph1c and
f1e1d surveys were conducted at three levels of deta11:(1)by us1ng only
eX1st1ng USGS topograph1c maps,w1th no supplemental surveys (for streams 1n
the Beluga area).(2)by us1ng ex1st1ng USGS topograph1c maps supplemented by
valley cross sect10ns (for the Talkeetna area along the Parks H1ghway),and
(3)by prepar1ng deta11ed topograph1c maps supplemented by valley cross
sect10ns and road and br1dge surveys (for deve1op1ng areas around Palmer and
Was111a).
-47 -
Table 18.Classification of·Wetlands in the Susitna Basin
(classification after Coward in et al.1979)
[
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System Subsyst_
PaIu.»:rJne:indudes all no
nCll'iUcfal wetlands dominated subsystem
by trees.shrubs.persJstant
emergent mosses or lichens,
and all such wetlands that
occur In tidal areas where
:1l:llnity due to CICUIWIerived
sa:ts is below 0""0100
(parts per ttJousand);also
inclUdes wetJaftds lacJdng
such vegetation.but with all
the following charae:terisdcs:
I)size less than 8 ha.
2)absen..-e 01 an active wave-
formed or bedrocll shoreline
future.3)wate!'""th in the
deepest pen of basin less than
2 m Jlt low watet.and salinity
due to oceanoderived saits less
than 0.5 01ll0;includes vege-
tated wetlancls traditionally
G1Jed by $Uch names as marsh,
Damp.bog.fen.and prairie;
also i&lcJudes the small.
shallow.~anent or Inter-
n-ittent water bodies often
:alle:d ponds.'
Oan-
Forested:i"dudes areas
In one of three SCS vege-
tation categories:
a)dosed forest.In which
tree canopy cover equals
or exceeds 60,..;b)open ,
forest.In which tree
canopy cover equals
25-59":lind c)woodland.
In which tree canopy cover
equals 10024"(trees ant
ddined by SCS as ''woody
plants having one well-
dfteloped stl!m and us..
aUy more than 12 It.In
height-'j
ScruJHhrub:Includes
areas dominated by woody
vegetation less than
J2 ft.tall;species
indude true shNbs,
young trees.and trees
or shrubs that are small
fir stunted because of
environmental conditions;
tree canopy cover Is less
than 10,....shNb cover
equals or exceeds 25.,..
Subc.lass
l'teedle-ieaweO
evergreen:predominant
woody life form Is
needle-leaved
evergreen
Broad.leaved
deciduous:predominant
woody life form Is
broad.Jeaved
cfeclduous
I'teedle-leatled eYer-
green and Broad-
leatreddedduous:
these two woody lire
forms are cHominant-
l'teedle-leatred
evergreen:predominant
woody life form under
12 It.tall Is needle-
leaved eYergreen
Broad·leaved
dedduous:predominant
woody life fonn under
J2 It.tall Is broad-
leaved dedduous
DominllRC&
Type
Pica IIIiIrlana:bllick
spruce constitutes
the dominant sub-
c:IaSs species
Populus balsamifera:
cottonwood (balsam
popular)constitutes
die dominant subclass
spedes
Plea martana:black
SllfUCe constUutu
die dominant subclass
species
scs
Code
'1
2
3
4
5
asFWS
Code
PF04
PFOI
PF040
PFOI
PSS4
PSSl
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•Sc.:::;C:efinitions nf vegetation classes coincide with Viereck a.,d Oyrneu (1950).dcflDitions of non·..~et,"ion dassn coincide wi:h,C:owc1fdin ~L aI,(19791-
Flat:includes all
wetlands haYing
three d1araeteris·
tia:(1)unconsoll·
dated substrates
with tess than 75%
areal cover 01 stones.
boulders.,or bedrock;
(2)less than 30".
areal cover ot veueta-
tlon other them
pioneering plants;3nd
(3)any appropriate
water regime (e.g.
regularly flooded)
Emergent:Includes areas
dominated by erect.rooted,
herbaceous hydrophytes;
this Yegetation Is present
for most of the growing
season In most years;tree
canopy cover Is less than
J0.,...shrub cover less than25.,..
EstilurlJ'le:indudes deep-
water tidal habitats and
adjacent tidal wetlands that
are \Isually semi-endosed by
Iar-d but have open.part'y
obstructed.or Sl)Oradic
ac:r:us to the open ocean,
and in ..,hich ocean water Is
.1t least occasionally diluted
by freshwater runof'from the
1an4;the salinity may be
periodlt'ally Increased above
that of t.'1e open ocean by
cvaroration.
IntertIdal:sub-
strate Is exposed
and nooded by
tides;includes the
usodated splash
'Zones
Scrub-shrub:(see
Palustrine.SCnIb-
shrub)
Emergent:(see
Palustrine.
Emergent)
Persistent:dominated
by species that normally
remain standing at least
until the beainning of
the next growing season
Broad-leaved decid-
uous:(see Palustrine.
Scrub-shrub.Broad-
leaved dedduous)
Persistent:(see
Palustrine.Emergent.
Persistent)
Mud:the uneonsolid...
ted particll:S smaller
than stones are
predominantly silt
and clay;anuerobic
conditions often exist
below the surf.1ce
Myrica:swe!:tgale 'or
other broad·lellived deci-
duous shrubs constitute
the dominant subclass
species
Elymus.CalamagroSo
tis:grasses constitute
the dominant subrlass
specieS
Selrpus,Carex,etc.:
emergent persistent
wetlands dominated by
rushes,sedges,or other
lorbs
6
11
12
13
14
PEM,I
E2SS1
E2EMl
E2EMJ
E2F1.3
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1/Data are presented for Talkeetna and Beluga Subbasins only.Data
collected for the Upper Sus1tna Subbasin are not in sufficient detail to
permit assignment to these categories.
-49 -
~/Totals do not add to 100.00 due to rounding.
Table 19.Wetland Types,Sus1tna River Bas1 nl/
%
1.41
4.53
0.12
0.65
0.64
0.54
13.08
7.42
0.73
0.00
2.34
68.52
99.98Y
9,250
7,900
9,530
Beluga
Acres
20,480
10,790
65,670
189,770
107,670
10,540
o
33,990
993,830
%
1.76
0.18
0.21
6.05
0.68
0.11
19.56
3.06
0.35
10.00
3.92
54.16
2,319,250 100.04~/1,459,420
Talkeetna
Acres
Emergent Pers1stant 70,890
Upper Perennial Riverine 232,000
Littoral and L1mnet1c 91,010
Non Wetland 1,256,050
Totals
Potential Palustrine Wetland
Inclusions 140,400
forested Needle Leaved Evergreen 40,920
Scrub/shrub Needle Leaved Evergreen
and Broad Leaved Deciduous 453,700
Intertidal Scrub/shrub Broad Leaved
Deciduous 2,510
Intertidal Emergent Pers1stant
(Calamagrost1s)4,110
Intertidal Emergent Pers1stant 4,760
Intertidal Unconsolidated Shore
Mud flat 8,110
forested Needle Leaved Evergreen and
Broad Leaved Deciduous 14,790
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Hydraulics
Elevation-discharge relationships were developed using the topographic and
field survey data referred to above.For Beluga area streams.elevat1on-
discharge relationships were developed for valley sections assuming normal
flow and using Manning's flow equat1on*.Hydraulic parameters existing prior
to 1981.i.e.pre-1981 phy~1cal characteristics of the channel and flood
plain.were used in the computations.High water marks.stream gage records.
and other historical flood data were used to test the accuracy of computed
water surfaces.
Three stream gages are located in the study area.Records from only one.on
the Skwentna River near Skwentna.are adequate for peak-frequency (pe~cent
chance of high water)analysis.TheChakachatna River gage near Tyonek is at
the mouth of Chakachamna Lake and.therefore.is not representative of peak
discharge from the area;and data from the Chu1tna River gage near Beluga are
too limited (covering only 1975-1981)for development of reliable
peak-frequency curves.For these reasons.the latter two gages were used only
to help in identifying historical high water marks.For Parks Highway streams
and Palmer-Wasilla area studies.elevation-discharge relationships were
developed for all bridges.culverts.and valley sections utilizing the Water
Surface Profile computer program (WSP2)outlined in SCS Technical Release
No.61 (USDA.1976).Hydraulic parameters of the channel and flood plain for
conditions prior to 1979 were used as input data for the WSP2 program.High
water marks.stream gage records.and other historical flood data were used in
checking the accuracy of the computed water surface profiles.Two stream
gages were located in these study areas.one on Cottonwood Creek and one on
Montana Creek.each with short periods of records (less than 10 years).These
records were utilized to help determine the accuracy of the computed
hydraulics.
Hydrology
Annual-peak-d1scharge studies have been made by the USGS for all of Alaska.
The USGS has published a regional analysis."Flood Characteristics of Alaskan
Streams"(Water Resources Investigations 78-129.1979).that presents regional
equations for determining peak discharges in two areas in Alaska.Area I and
Area II.This river basin study is located in Area II.Curves showing the
frequency or percent chance of high water (peak-frequency curves)were.
therefore.developed by using both the equation proposed by USGS and the
Log-Pearson Type III method.High water (peaks)calculated by these two
methods for given frequency storms were compared to determine the adequacy of
the regional equation for this study.These comparisons indicated that the
regional equation was adequate for the relatively flat lowland areas of
Wasilla.Cottonwood.and Lucile Creeks;however.for Kashw1tna River and
Parks Highway streams.Peters Creek.and Beluga streams.the regional equation
*Manning's equation is used to calculate stream flows given existing
channel characteristics.
-50 -
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was determined to be inadequate.As a result,stream gage records within the
Southcentral Region were used to develop peak-frequency curves in an effort to
obtain more reliable peaks for the study area.
A range (upper and lower curves)for high,medium,and low peak discharges for
the 2-year,10-year,50-year,100-year and 500-year events was developed.
(See Appendix E,Exhibits 5,6,7,8,and 9 of the "Flood Hazard Study for
196 Mile,Caswell,Sheep,Goose,Montana,Answer,and Birch Creeks"by SCS,
1981.)These curves,and watershed characteristics such as watershed slope,
channel length and slope,mean elevation,land cover,and average annual
precipitation,were used to develop a curve showing the frequency of
peak-discharges produced by the events mentioned above for each watershed at
each cross section.
Cottonwood and lucille Creeks both run through lakes for long distances.
Discharges at the outlets of the lakes were found to control water surface
elevations downstream from the outlets.Peak discharges were determined at
the lake outlets;from that point downstream,watershed areas above the lake
outlets were considered noncontributing to the stream stage.
The peak discharges of the 10-,50-,100-,and 500-year storm events for each
watershed area above each cross section were determined from the curves
described above and then used to determine water surface elevations and area
inundated on each stream.The area inundated by the 100-year frequency event
was outlined on flood plain maps as a part of each study.Table 20 provides a
list of streams studied in the basin,and for each,indicates area subject to
flooding from the 100-year frequency event.
The major areas studied are shown on Figure 6.In addition to the information
provided above,all reports contain maps showing the potential areas of
inundation,as well as information on historical floods and flood damage
potential.
-51 -
Table 20.Streams Studied in the Susitna River Basin.
and Areas of Each Subject to Flooding (100-year flood p1a1n)
196 Mile Group
Stream
196 Ml1e Creek
Caswell
Sheep Creek
Goose Creek
Montana Creek
Answer Creek
Birch Creek
Chulitna G~oup
Stream
Troublesome Creek
Byers Creek
Honolulu Creek
East Fork of Chulitna River
Middle Fork of Chulitna R1ver
Kroto Group
Stream
Kroto Creek
Moose Creek
Nineml1e Creek
Gate Creek
Twentymi1e Creek
Seventeenmi1e Creek
Peters Creek
Kenny Creek
RaM deux Creek
Trapper Creek
-52 -
Area Subject
to Flooding
(acres)
400
850
3.450
570
1.480
140
80
Total 6.970
Area Subject
to Flooding
(acres)
20
40
60
840
1700
Total 2.660
Area Subject
to Flooding
(acres)
2.880
4.780
620
280
100
80
600
120
570
2,.770
Tota 1 12.800
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Table 20.Streams Studied in the Susitna River Basin.and Areas of Each
Subject to flooding (lOO-year flood plain)(continued)
Total 306.600
Area Subject
to Flooding
(acres)
Area Subject
to Flooding
(acres)
1.770
1.050
310
170
240
51.800
87.700
1.000
900
2.200
23.000
140.1 000
Total
-53 -
KashwHna River
Wasilla Creek
Cottonwood Creek
lucile Creek
Kustatan River
McArthur.Chakachatna.and
Chuitkinachna Rivers
Old Tyonek Creek
Tyonek Creek
ChuHna River
Beluga.Theodore.and
lewis Rivers
Yentna and Tributaries
KashwHna Group
Stream
Beluga Group
Stream
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FIGURE e'",Nt-Utli
SUSITNA RIVER BASIN
AlASKA
AUGUST ttll
..•..•...q
.!!!5
HAZARD GROUPS
MANAGEMENT GROUPS
It""
/CHIli
\
I
Ladd
.~~/'/'TJio.t.f -{'oquaw,te --__..WI'S"'................~J/~~MI ::::"_..tCI.-._:IioolMIIWICI _~._.V..O«__OIAG __•__
:
rt:';rt r::J c-:J c--J ~r1J L.J rro r::-J c::-J r::J r--J r--J rj r-J r-J .c-j ~
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e
E.Objective:Ident1fy the econom1c value of selected recreat10nal
resources w1th1n the bas1n.
Rat10nale:To 1ncrease pub11c awareness of the econom1c values
assoc1ated w1th recreat10nal resources and thus prov1de an 1nd1cat10n of
econom1c trade-offs that would result from selected changes 1n land-use,e.g.,
convert1ng ex1st1ng recreat10nal lands to,for example,settlement lands.
Analys1s:N1 ne l/recreat10nal act1v1t1es were exam1ned
bas1n-w1de.Those act1v1t1es were:
Small game hunt1ng
Waterfowl hunt1ng
Kayak1ng/Canoe1ng
Cross-country sk11ng
Snowmob11 1ng
H1k1ng w1th pack
P1cn1ck1ng
Tent camp1ng
Recreat10nal veh1cle camp1ng
For each act1v1ty,est1mates were made of demand from and econom1c value~/
to recreat10nal part1c1pants from four p01nts of or1g1n:1)Anchorage,
2)Fa1rbanks,3)the Mat-Su Borough,and 4)outs1de Alaska (nonres1dents).
Levels of demand from w1th1n Alaska were est1mated based on part1c1pat10n
rates presented 1n DNRls 1981 Alaska Outdoor Recreat10n Plan,wh11e
nonres1dent demand levels were der1ved from the 1977 V1s1tor Expend1ture
Survey comm1ss10ned by the Alaska Department of Commerce and Econom1c
Development.
Recreat10nal values were est1mated us1ng the travel cost method (TCM}.The
TCM assumes that the value of a recreat10nal act1v1ty 1s equal tpthesum of
the round tr1p costs 1ncurred by part1c1pants 1n ga1n1ng access to
recreat10nal s1tes.Res1dent travel costs used 1n th1s study 1nclude only
var1able costs for auto/truck travel,and both var1able and f1xed costs for
Recreat10nal Veh1cle travel.For nonres1dents.costs for round tr1p
transportat10n to Alaska,as well as 10dg1ng and spec1al 11cense fees (where
app11cable).have also been 1ncluded.
1/The Alaska Department of F1sh and Game conducted s1m11ar analyses for
freshwater f1sh1ng and b1g game hunt1ng (see references c1ted under recreat10n
1nventory).The USDA ass1sted ADF&G w1th port10ns of th1s work.
y In th1s case econom1c value 1s 11mited to transportat10n costs d1scussed
on the follow1ng page.
-55 -
All human use figures in the analysis are expressed as user days.A user day
is any portion of a 24-hour period in which an 1nd1~1dual(user)participates
in a particular recreational activity.(A person wha camps overnight.
picnics.and then hikes a scenic trail during one 24-hour period has completed
3 user days.one for each act1v1ty~)In the travel cost method.monetary
user-day values for any recreational activity increase as users travel farther
to engage in that activity.In order to take this distance factor into
account.monetary values of each recreational activity were computed based on
both distances traveled to reach that activity and number of users traveling
those distances.Concentric travel-time zones (each representing 1 hour of.
travel.or 45 m11es).-were drawn radiating out from cities within and outside
the basin.User-day values could then be computed for all activities within
each zone by estimating how many users recreated within that zone and how far
that zone was from users'po1nts-of-or1g1n.
Table 21 presents total user days in all zones (hourly driving intervals)that
fall within basin boundaries.This table also converts use into facility
demand based on composite factors set forth in Table 22.
Results:Table 23 summarizes the economic value of each selected recreational
activity within the planning area.Values estimated represent only a portion
of the total value of fish and wildlife and recreational resources.Even
though the analyses conducted by ADF&G on freshwater fishing and big game
hunting will yield values additional to those of the nine activities examined
here.the total estimated value for all analyzed recreational activities will
still·fall short of the actual total value of recreat1on~l resources for two
major reasons:
1)Many activities have not been considered.and
2)Many other expenses.e.g.gear.more costly alternative travel modes.
etc .•have not been included.-
In addition to the demand and value analysis described above.an attempt was
made to determine unit values of meat and fish harvested.These values are
presented in Table 24 and have been utilized in part by ADF&G for estimating
basinwide total harvest values.It should be noted that for a significant
portion of the population.unit value~in tables 23 and 24 would be additive.
F.Objective:Develop an integrated automatic data processing
capability to handle collected resource data~Use data process1n~capability
to evaluate and select land uses for the Sus1tna Basin.
Rationale:Early in the Sus1tna Basin study.it became apparent that
analyzing the large volume of land-based geographic information being
collected would require the use of computers.As a result.a data processing
system was developed to handle analysis of river bastn data.and to facilitate
the use of basin data for making land-use decisions.
-56 -
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Table 21.Existing Recreational Demandll
Annual User Day Demand :Facility Demand (Peak Day)21
::
Total :facl1 Hy UnHs :Total.:.
Kayak1ng/Canoe1ng 70.524 stream miles 88.2
Cross-country skiing 99.585 tral1 miles 92.6
Snowmobiling 95.341 tral1 ml1es 59.5
Hiking 74.713 tral1 ml1es 62.3
Picnicking 376.987 sHes 502
Rec.vehicle camping 120.064 sites 832
Tent camping 107.371 sHes 447
Waterfowl hunting 19.065 Not A v ail a b 1 e
Small game hunting 44.068 Not A v ail a b 1 e
II Includes Residents and Non-Residents.
£1 A peak day is defined as that day in which maximum daily use occurs.
-57 -
66.67 1 =.0126 ml1es.
Table 22.Standards for selected re~reatlona1 actlvltles
.·:..·1 :2 :3 :4 .5..::Composite
:"of1/;"of1l ·:factor·:tota1 annual :tota1 annua1:Facl11tles1/:(facilitles
:demand :demand :requlred :requlred per
:occurrlng :requlrlng :per demand :user day)
Activity :on peak day :fac11itles :day :(2 x 3 x 4 )~
:::
Stream Flshlng 1.56 100 Y .0126 ml if .000197
Lake Flshlng 1.56 50 i/.053 units ~/.000413
Kayaklng/Canoelng 2.5 75 .0667 ml .001251
Cross-country Skllng 1.55 90 .0667 ml .000930
Snowmob111 ng 1.04 90 .0667 ml .000624
Hlklng 2.5 50 .0667 ml .000834
Plcnlcklng 1.88 52 .136 units .001330
RV Camplng 2.5 100 .277 units .006925
Tent Camplng 2.5 Y 50 Y .333 unl ts II .004163
1/Derlved from Alaska Outdoor Recreatlon Plan (1976-1980),Alaska Dlvlslon
of Parks.
£/Assumed to be same as hlklng.
3/Slnce facl11tles ln thls case are ln terms of stream ml1es,all users
requlre facl11tles.
i/No data aval1ab1e -thls ls an SCS estlmate -assumed same as hlklng.
if Estlmated by SCS as follows:
100 1 /person 1.5 turnover =66.67 1 person/day
~Estlmated by SCS as follows:1 ramp accommodates 5 veh.plus tral1ers;
day capaclty =5 veh.x 2.5 persons/veh.x 1.5 turnover =18.75 persons;
1 person needs 1/18.75 ramps =.053 ramps (unlts).
1/Estlmated by SCS as follows:
3 persons/slte 1 T 3 =.333 sltes/person.
~/The product of these factors and demand equals total facl11tles requlred.
-58 -
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Table 23.EXisting Recreational Value
Susitna Planning Area Excluding Willow Subbasin
(1982 Dollars)
Total Annual :Total Annual .Total .Total..
Recreation Value :Recreation Value :Annual :Present
Activity :to Residents :to Non-Residents :Value :Value II..::..
Kayakingl 1.682.620 143.539 1.826.159 18.106.000
Canoeing
Cross-country 897.300 195.472 1.092.772 10.834.600
Skiing
Snowmobiling 2.958.362 235.047 3.193.409 31.662.000
Hiking 588.780 124.825 713.605 7.075.300
Picnicking 3.696.140 3.055.223 6.751.363 66.938.500
Rec.Vehicle 676.940 4.649.081 5.326.021 52.806.500
Camping
Tent Camping 837.540 627.078 1.464.618 14.521.400
Waterfowl 507.180 45.537 552.717 5.480.100
Hunting
Small Game 1.240.391 97.660 1.338.051 13.266.500
11 Based on 50 year evaluation period.10%discount rate.
-59 -
1/Values were based on average costs of obtaining comparable amounts of
protein from 23 specified meats and meat alternatives.These 23 items are
as follows:
Table 24.
Food Item
Black Bear
Beaver
Caribou
Duck (Eider)
Moose
Reindeer
Salmon (wet weight)
Chinook
Chum
Coho
Pink
Sockeye
Fish and Game Protein Values 1/
Value/lb.
(2nd quarter 1982
projected price base)
3.16
4.21
4.21
3.16
4.21
3.16
4.12
4.52
4.37
4.31
4.27
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Peanut butter
Bread,white enriched
Dry beans
Eggs,large
Chicken,ready-to-cook
Bean soup,canned
Milk,whole,fluid
Ground beef
Chicken breasts halves
Beef liver
Tuna,canned
Turkey,ready-to-cook
-60 -
Processed American cheese
Cured ham
Round beefsteak,bone in
Ocean perch fillet,frozen
Frankfurters
Chuck roast of beef,bone in
Rump roast of beef,boned
Pork chops,center
Bologna
Bacon,sliced
Porterhouse beefsteak
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Analysis:Once the need for computer processing of basin data was
r~cogn1zed.a computer contractor (Environmental Systems Research Institute.
Redlands.California)was selected to work with study participants in
automating and analyzing basin data.Working with stat~and federal resource
specialists and planners.ESRI rectified.digitized.and automated all
available land-based data for the Talkeetna.Beluga.and Upper Sus1tna
Subbasins.In addition.agency and ESRI personnel together developed computer
"models"for analyzing automated data.Models were designed to assess natural
opportunities for and constraints on implementing different land uses
throughout the basin.based on inventoried environmental conditions.Results
of model analyses were presented on computer-generated maps that showed basin
lands rated in terms of their sUitability to support different land uses.
Computer models were based on land suitability "criteria"selected by resource
specialists and land planners.Criteria reflected the assumed effects of
particular mapped environmental conditions upon particular land uses.For
example."slope"represented one mapped environmental condition ,that affected
the use of land for settlement.It was assumed that slopes exceeding 30%
would be "unsuitable"for settlement because of the potential difficulties of
clearing and building on such slopes.and because of the potential damages
(erosion.mass wasting)that development on such slopes could cause."Slope
percent."therefore.became one land sUitability criterion in the settlement
"model.11 Likewise.certain vegetation types were assumed to be conducive to
"remote lJrge lot"settlement because they could provide timber for house logs
and/or firewood;so the presence of such vegetation types became a sUitability
criterion in the "remote settlement"model.
All computer suitability models were based on automated environmental data;
however.some analyses were based directly on the field data.while others
were based on additional interpretations of those data.Development of
suitability models.and criteria used in each.are described in detail in:
Final Report Computerized Geographic Information System.Talkeetna and Beluga
Subbasins,Sus1tna River Basin,Alaska (ESRI.1982).In addition.examples of
suitability models are presented in Appendix D.
Results:Data processing was essential in developing land-use plans
for state and borough lands in the Sus1tna Basin.Alternative land use plans
developed using data processing methods outlined above are described in
"elements"prepared by DNR and ADF&G with USDA input.These elements have
been published by DNR.one element for each land use:agriculture.fish and
wildlife.forestry.recreation.settlement.subsurface resources.and
transportation.The final proposed land use plan for the basin.developed by
the state and borough through a process of negotiating and balancing
trade-offs among potentially suitable land uses.and involving considerable
public input and review.is presented in:Sus1tna Area Plan Public Review
Draft -Summary (DNR.1984).
-61 -
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III.Appendlces
APPENDIX A
Supplementary Reports
Prepared by or for the USDA:
(Those markedwHh an *arecontalned ln full in:SusHna River Basin Study
Summary of USDA Investigations and Analyses [USDA SCS,1985])
Economics:
1.The Sus1tna Cooperatlve River Basin Study Economic Development
Analysis (P.Fuglestad and J.0'Ne111.1983.USDA ERS.SCS)
2.*A Methodology for Estimating Road Costs in the SusHna River Basin
(P.Fuglestad and J.O'Neill.1983.USDA ERS.SCS)
Water Resources:
1.*Mean Annual Precipitation and Water Yield in the Sus1tna River
Basin (E.Merrell.1979.USDA SCS)--
2.SusHna Basin Plannlng Background Report -Water Supply and Demand
(B.Loeffler.1980.ADNR in cooperation with USDA)
3.SusHna Basin Water QualHy Report (B.Rummell.no date.for USDA
SCS,FS.ERS)
So11s:
1.Soil Survey -Sus1tnafast Area.Alaska (USDA SCS,in progress)
2.Sol1 Survey -Yenta Area.Alaska (USDA SCS,in progress)
Land Treatment and Agronomy:
1.Alaska Irrigation Gulde (E.Merrell.in progress,USDA SCS)
Geology:
1.Geology Report for the Talkeetna Subbasin.Sus1tna River Basin Alaska
Cooperative Study (S.Sumslon.1979.unpublished report prepared for
the USDA SCS)
land Cover (Vegetation):
1.Preliminary Field Procedures for the Cooperative Vegetation Inventory
of the Sus1tna River Basin.Alaska (USDA FS.PNW,1979)"'
-62 -
2.Resource Statistics for the Sus1tna River Basin (C.Steele,SCS FSl,
W.Watts,USDA SCS,in progress)
3.Timber Resource Statistics for the Talkeetna Block,Sus1tna River
Basin Mu1t1resourcelnventory Unit,~aska (T.Setzer,G.l.Carroll,
B.R.Mead,1979,USDA FS,PNW Forest and Range Experiment Station)
Recreation:
·1.Recreation Atlas -Willow-Talkeetna Basin (ADNR in cooperation 'with
USDA,1979)
Archeological,Historical,and Cultural Resources:
1.Cultural Resource Assessment:Talkeetna-lower Sus1tna River Basin,
Southcentra1 Alaska (G.Bacon,J.Kar1 ,and T.Co1e,1982,for USDA
SCS,FS,ERS).
2.Cultural Resource Assessment:·Talkeetna-lower Sus1tnaRtver Basin,
Southcentra1 Alaska (supplemental report)(G.Bacon andT.Co1e,
1982,for USDA SCS,FS,ERS)
3.Cultural Resource Assessment:Beluga Study Area,Southcentral Alaska
(G.Bacon,J.Kar1,T.Cole,C.Mobley,and R.Carlson,for USDA SCS,
FS,ERS).
Fish and Wildlife and Wet1and1:
1.Identifying Wildlife lands:Fish and Wildlife Ana1yse1 for the
Sus1tna River Basin Study (D.lehner,1984,USDA SCS)
2.*Wetlands Mapping in the Sus1tna River Basin (USDA SCS,1984)
Flood Plain Management:
1.Flood Hazard Study,196 Mile,Caswell,Sheep,Goose,Montana,Answer,
and Birch Creeks and Tributaries (E.Grey,1981,USDASCS)
2.Flood Plain Management Study,Beluga Streams (E.Grey,1982,USDA SCS)
3.Flood Plain Management Study,KashwHna River;Was1l1a,Cottonwood,
and Luelle Creeks (E.Grey,1982,USDA SCS)
4.Flood Hazard Study,Kroto,Rab1deux,Trapper,and Peters Creek
(E.Grey,1982,USDA SCS)
5.Flood Hazard StUdy,Troublesome,Byers,and Honolulu Creeks;East and
Middle Forks of the Chulitna (E.Grey,1981,USDA SCS)
-63 -
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Data Processing (Geographic Information Systems):
1.Final Report:Computerized Geographic Information System -Talkeetna
and Beluga Subbasins,Susitna River Basin,Alaska (ESRI,1982,for
USDA SCS,FS)
2.Final Report:Computerized Geographic Information System -Upper
Sus1tna Subbasin (ESRI,1983,for USDA SCS,FS)
Bibliographies:
1.Sus1tna River Basin Resource Bibliography (ADNR in cooperation with
USDA,1977)
2.Sus1tna River Basin Resource Bibliography,supplement 1979
(D.Lockhart,1979,ADNR in cooperation with USDA SCS,FS,ERS)
Prepared by other agencies with USDA assistance:
1.Land Status Atlas -Sus1tna River Basin (Alaska Department of Natural
Resources,1978)
2.Land Use Issues and Preliminary Resource Inventory (volume 1 of 2)
Growth Potential,Development Issues,Settlement Patterns (volume 2
of 2)(Alaska Department of Natural Resources,in cooperation with
the Hatanuska-Sus1tna Borough,Alaska Department of Fish and Game,
Alaska Department of Transportation and Public Facilities,Kenai
Peninsula Borough,and USDA,1982)
3.Hatanuska-Sus1tna Borough Comprehensive Plan (Hatanuska-Sus1tna
Borough)
4.Resource Elements (Department of Natural Resources,1984)
a.AgricUlture Element for the Sus1tna Area Plan
b.Fish and Wildlife Resources Element for the Sus1tna Area Plan
(Alaska Department of Fish and Game)
c.Forestry Element for the Sus1tna Area Plan
d.Settlement Element for the Sus1tna Area Plan
e.Recreation Element for the Sus1tna Area Plan
f.Subsurface Resources Element for the Sus1tna Area Plan
-64 -
5.Response to Public Comments on the Draft SusHnaArea'Plan (Alaska
Department of Natural Resourc~sf 1985),
6.SusTtnir'AreaPlan (Public Review Draft)fAlaskaDepartmentof Natural
Resources.in coop~ranon wHh the Matanuska-"Susltna Borough.Alaska
Department of Fish and Game,Alaska Department of Transportation and
PubliC Fac:HUies.Kenai P~ninsula Borough.USDA.and BLM.1984)
...
7.SusHna Area Plan (Final Draft)(Alaska Departrilentof'Natural
Resources.in cooperation with the Matanuska-SusHna Borough.Alaska
Department of Fish and Game.Alaska Department of Transportation and
Pub lic,fac11 it ies.Ke.nai Peninsula Borough •USDA.and BLM.1985)
8.Susitna Area Plan Land Use Alternatives (Alaska Department of Natural
Resources~1983)
9.SusHna Area Plan.Public Workshops Spring 1983.Summary of Results
and Staff Analysis (Alaska Department of Natural Resources.Resource
Allocation Section.Division of land and Water Management.1983)
10.A Synthesis and Evaluation of ADF&GFish andWHdlHe Resources
Information for the Willow and Talkeetna Subbasins (Alaska Department
of Fish and Game.1983)
-65 -
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APPENDIX 8
Linear Programming Assumptions and Results
Table 8-1 identifies those assumptions (parameters)used in developing each of
the agriculture/timber development alternatives.Table 8-2 presents the
results of each of those alternatives.Assumptions used were provided by the
Alaska Department of Natural Resources.
The Talkeetna mathematical programming model is a modification of the Willow
Subbasin model (Fug1estad).While several differences exist between the
models because of a change in study direction and emphasis,the two models
share a common philosophy in terms of their objective and structure.The
objective of both is to maximize the present value of net benefits of timber
and agricultural development in the study area.The model was used to run the
25 alternative analyses.
U The model maximizes net benefits subject to'limitations of land,timber,and
accessibility.
~Unless otherwise noted all benefits and costs are on a 1983 price base.u
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-66 -
-67 -
Table B-1.Alternative Parameters
11 portion of total road cost allocated to timber and agriculture development.
(MBF/yr)6,600
(cords/yr)11,000
(mmbu/yr)57.5
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20
20
3.12
160.00
125.00
75.00
146.69
146.69
97.24
35
1
100
300.00
20-70
10·
52.5
47.5
1,246
283.9
23,400
37,500
57.5
20
20
3
3.12
160.00
125.00
75.00
146.69
146.69
97.24
35
1
100
300.00
52.5
47.5
1,246
283.9
20-70
7 5/8
23,400
37,500
57.5
2
20
20
Alternatives
3.12
160.00
125.00
75.00
146.69
146.69
97.24
35
1
100
300.00 .
0-50
10
52.5
47.5
1,246
283.9
6,600
11,000
57.5
20
20
1
3.12
160.00
125.00
75.00
146.69
146.69
97.24
35
1
100
300.00
50
50
1,246
283.9
0-50
7 5/8
(%)
(%)
(%)
($lac)
($/ac r
($/ac)
($/hr)
Unit
(bu/ac)
(bu/ac)
3(ft lac)
(ft 3/hr )
(beginning
and ending)
(%)
($/bu)
($/MBF)
($/MBF)
($/cord)
50-year
analysis period
Discount rate
Road costs:
Overhead (%of construction cost)
O&M (%of construction cost)
11Timber/ag cost share-
Clearing cost
Production cost:
Barley -Class II land
Barley -Class III land
Logging
Overhea"d:
Barley
Logging
Barley yield:
Class II land
Class III land
Timber volume
Logging productivity
Prices:
aarley
Spruce logs
Cottonwood
FueTwood
Demand"ceilings:
Sawlogs
Fuelwood
Barley
Parameters
-68 -
Table B-1.Alternative Parameters (continued)
II portion of total road cost allocated to timber and agriculture development.
8
20
20
3.96
160.00
125.00
75.00
146.69
146.69
97.24
.35
1
10
300.00
52.5
47.5
1.246
283.9
0-50
7 5/8
6.600
11,000
57.5
7
20
20
146.69
146.69
97.24
3.96
160.00
125.00
75.00
35
1
100
300.00
52.5
47.5
1.246
283.9
0-50
7 5/8
6,600
11.000
57.5
20
20
6
Alternatives
3.96
160.00
125.00
75.00
35
1
100
300.00
146.69
146.69
97.24
52.5
47.5
1.246
283.9
20-70
10
23.400
37,500
57.5
20
20
5
146.69
146.69
97.24
3.96
160.00
125.00
75.00
35
1
100
300.00
52.5
47.5
1.246
283.9
20-70
7 5/8
23.400
37.500
57.5
(%)
(%)
($/ac)
($/ac)
($/hr)
UnH
(MBF/yr)
(cords/yr)
(mmbu/yr)
($/bu)
($/MBF)
($/MBF)
($/cord)
(beginning
and ending)
(%)
(bu/ac)
(bu/ac)
3(ft lac)
(ft 3/hr)Logging productivity
Prices:
Barley
Spruce logs
Cottonwood
Fue1wood
Demand ceilings:
Saw10gs
Fue1wood
Barley
50-year
analysis period
Discount rate
Road costs:
Overhead (%of construction cost)
O&M (%of construction cost)
11Timberlagcostshare-(%)
Clearing cost ($/ac)
Production cost:
Barley -Class II land
Barley -Class III land
Logging
Overhead:
Barley
L09.ging
j~Barley yield:
Class II land
Class III land
Timber volume
Parameters
c
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-69 -
II port1on of total road cost allocated to t1mber and agr1culture development.
Table B-1.Alternat1ve Parameters (cont1nued)
[,
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12
175.30
175.30
144 ..52
35
1
10
300.00
3.99
178.00
125.00
75.00
17
~O
0-50
10
52.5
47.5
1,246
517 .0
86,858
98,764
82.75
17
20
35
1
o
250.00
3.99
178.00
V5.OO
75.00
175.30
175.30
144.52
11
0-50
10
52.5
47.5
1,246
517·.0
86,858
98,764
82.75
20
20
146.69
146.69
97.24
10
Alternat1ves
3.96
160.00
125.00
75.00
52.5
.47.5
1,246
283.9
0-50
7 5/8
35
1
33 1/3
300.00
6,600
11,000
57.5
9
20
20
35
1
20
300.00
146.69
146.69
97.24
3.96
160.00
125.00
75.00
52.5
47.5
1,246
283.9
0-50
7 5/8
6,600
11,000
57.5
(%)
(%)
Unit
(bu/ac)
(bu/ac)
3(ft lac)
(ft3/hr)
(MBF/yr)
(cords/yr)
(mmbu/yr)
(beg1nn1ng
and end1ng)
(%)
($/bu)
($/MBF)
($/MBF)
($/cord)
II land ($lac)
III land'($/ac)
($Ihr)
T1mber volume
Logg1ng product1v1ty
Pr1ces:
Barley
Spruce logs
Cottonwood
Fuelwood
Demand ce111ngs:
Sawlogs
Fuelwood
Barley
50-year
analys1s per10d
D1scount rate
Road costs:
Overhead (%of construct10n cost)
O&M (%of construct10n cost)
11T1mber/ag cost share-(%)
Clear1ng cost ($/ac)
Product10n cost:
Barley -Class
Barley -Class
Logg1ng
Overhead:
Barley
Logg1ng
Barley y1eld:
Class II land
Class II I land
Parameters
...."
---1
~1
.•..i Table B-1.Alternative ,Parameters (continued)
Alternatives-,
I
_~1
Parameters Unit
13 14 15 16
-,
(MBF/yr)86.858
(cords/yr)98.764
(mmbu/yr)82.75
17
20
35
1
50
325.00
177.52
175.30
144.52
3.99
178.00
125.00
75.00
0-50
10
57.5
52.5
1.246
517 .0
86.858
98.764
82.75
17
20
35
1
10
300.00
177.52
175.30
144.52
3.99
178.00
125.00
75.00
0~50
10
57.5
52.5
1.246
517 .0
86.858
98.764
82.75
17
20
o
o
o
250.00
3~99
178.00
125.00
75.00
177.52
173.04
144.52
0-50
10
52.5
47.5
1.246
517 .0
86.858
98.764
82.75
17
20
3.99
178.00
125.00
75.00
35
1
50
325.00
175.30
173.04
144.52
0-50
10
52.5
47.5
1.246
517 .0
($/ac)
($/ac)
($/hr)
(%)
(%)
(bu/ac)
(bu/ac)
(ft 3/ac)
(ft 3/hr)
(beginning
and ending)
(%)
($/bu)
($/MBF)
($/MBF)
($/cord)
Barley
Logging
Barley yield:
Class II land
Class III land
Timber volume
Logging productivity
Prices:
Barley
Spruce logs
Cottonwood
Fuelwood
Demand cen ings:
Sawlogs
Fuelwood
Barley
50-year
analysis period
Discount rate
Road costs:
Overhead (%of construction cost)
O&M (%of construction cost)
Timber/ag cost sharel!(%)
Clearing cost ($/ac)
Production cost:
Barley -Class II land
Barley -Class III land
Logging
Overhe~d:
--J
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c
c
II portion of total road cost allocated to timber and agriculture development.
-70 -
-71 -
Table B-1.Alternative Parameters (continued)
II portion of total road cost allocated to timber and agriculture development.
y zero prices were used in order to enable the model to allocate all costs to
either timber development or agricultural development.
[,
p
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[
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[
[
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17
20
o
o
10
225.00
20
169.83
169.83
144.00
4.20
178.00
125.00
75.00
0-50
7 7/8
55.0
52.5
1.246
465.0
17
20
o
o
10
225.00
172.24
172.24
144.00
3.99
178.00
125.00
75.00
19
0-50
7 7/8
55.0
52.5
1.246
413.6
86.858 86.858
98.764 .98~764
82.75 82.75
Alternatives
3.99
oy
o 'l.1
o 'l.1
17
20
o
o
o
300.00
177.52
175.30
144.52
18
0-50
10
57.5
52.5
1.246
517 .0
86.858
98.764
82.75
17
20
o
o
o
300.00
o 'l.1
178.00
125.00
75.00
175.30
173.04
144.52
17
0-50
10
52.5
47.5
1.246
517 .0
86.858
98.764
82.75
(%)
(%)
($/ac)
($/ac)
($/hr)
Unit
(beginning
and ending)
(%)
(MBF/yr)
(cords/yr)
(mmbu/yr)
(bu/ac)
(bu/ac)
(ft 3/ac)
(ft 3/hr )
($/bu)
($/MBF)
.($/MBF)
($/cord)
II land
III land
Barley
Spruce logs
Cottonwood
Fue1wood
Demand ceni ngs:
Saw10gs
Fue1wood
Barley
Barley -Class
Barley -Class
Logging
Overhead:
Barley
Logging
Barley yield:
Class II land
Class III land
Timber volume
Logging productivity
Prices:
50-year
analysis period
Discount rate
Road costs:
Overhead (%of construction cost)
O&M (%of construction cost)
11T1mber/ag cost share-(%)
Clearing cost ($/ac)
Production cost:
Parameters
I'
[Table B-1.Alternative Parameters (continued)
-72 -
11 P9rtion of total road cost allocated to timber and agriculture development.
17
20
4.20
178.00
125.00
75.00
o
o
10
250.00
169.83
169.83
172.00
24
0-50
7 7/8
55.0
52.5
1,246
517 .0
86,858
98,764
82.75
17
20
3.99
178.00
125.00
75.00
o
o
10
250.00
157.25
157.25
144.00
23
0-50
7 7/8
55.0
52.5
1,246
517 .0
86,858
98,764
82.75
17
20
Alternat1ves
3.99
178.00
125.00
75.00
o
o
10
250.00
169.83
169.83
144.00
22
0-50
7 7/8
55.0
52.5
1,246
517 .0
86,858
98,764
82.75
17
20
4.20
178.00
125.00
75.00
o
o
10
250.00
172.24
172.24
144.00
21
0-50
7 7/8
55.0
52.5
1,246
568.7
86,858
98,764
82.75
(%)
(%)
(%)
($/ac)
Unit
(MBF/yr)
(cords/yr)
(mmbu/yr)
($/bu)
($/MBF)
($/MBF)
($Icord)
(bu/ac)
(bu/ac)
(ft3lac)
(ft 3/hr)
(beginning
and ending)
(%)
II land ($/ac)
III land ($/ac)
($/hr)
Logging productivity
Prices:
Barley
Spruce logs
Cottonwood
Fuelwood
Demand ceilings:
Sawlogs
Fuelwood
Barley
50-year
analysis period
Discount rate
Road costs:
Overhead (%of construction cost)
O&M (%of construction cost)
11Timberlagcostshare-
Clearing cost
Production cost:
Barley -Class
Barley -Class
Logging
Overhead:
Barley
Logging
Barley yield:
Class II land
Class III land
Timber volume
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Table B-1.Alternative Parameters (continued)
II portion of total road cost allocated to timber and agriculture development.
-73 -
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Alternatives
17
20
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225.00
3.99
178.00
125.00
75.00
169.83
169.83
200.00
25
0-50
7 7/8
55.0
52.5
1.246
517 .0
86.858
98.764
82.75
(%)
(%)
($/ac)
($/ac)
($/hr)
Unit
(MBF/yr)
(cords/yr)
(mmbu/yr)
(beginning
and ending)
(%)
(bu/ac)
(bu/ac)
(ft 3/ac)
(ft 3/hr )
($/bu)
($/MBF)
($/MBF)
($/cord)
logging productivity
Prices:
Barley
Spruce logs
Cottonwood
Fuelwood
Demand cellings:
SawlQgs
Fuelwood
Barley
50-year
analysis period
Discount rate
Road costs:
Overhead (%of construction cost)
O&M (%of construction cost)
11Timber/ag cost share-(%)
Clearing cost ($/ac)
Production cost:
Barley -Class II land
Barley -Class III land
.logging
Overhead:
Barley
logging
Barley yield:
Class II land
Class III.land
Timber volume
Parameters
"
.-1
"'--'
--l Table B-2.Alternative Results
-,
Results Unit
Alternatives
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1 2 3 4
Total benefits (thousand 6.424 4.983 1.478 741
dollars)11
Net benefits (thousand 2.218 1.605 510 239
dollars)
B/C (ratio)1.53 1.48 1.53 1.48
Roads built:
length (miles)2.81 2.81 2.81 2.81
Cost (thousand 564 553 130 82
dollars)y
lP units accessed (map no.)8.17.18 8.17.18 8.17.18 8.17.18
Acres~in production:
Agriculture (ac/yr)-0--0--0- -0-
Timber (ac/yr)556 556 556 556
Commodities produced:
Barley (thous.bu.)-0--0--0- -0-
Spruce sawlogs (MBF)782 782 782 782
Cottonwood sawlogs (MBF)714 714 714 714
Fuelwood (cords)3.842 3.842 3.842 3.842
Annual employment:
Agr 1culture (person years)-0--0--0--0-
Timber (person years)6.1 6.1 6.1 6.1
l!All dollar figures are 1983 values.
,£1 Includes overhead and present value of O&M costs.
11 These figures are on an annual basis.Since agricultural enterprises
utilize the same acres year after year.th~acreage figures for
agriculture are total acres feasible for the evaluation period.Timber
acreage.however.must be adjusted because different acres are utilized
annually.To determine total feasible timber acres.multiply annual acres
in production times length of the evaluation period in years.For
example.the total feasible timber acres for alternative no.1 is 556
acres times 50 years or 27.800 acres.
-74 -
1/All dollar figures are 1983 values.
'f/Includes overhead and present value of O&M costs.
-75 -
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11 All dollar figures are 1983 values.
£!Includes overhead and present value of O&M costs.
-76 -
!!All dollar figures are 1983 values.
f/Includes overhead and present value of O&M costs ..
-77 -
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--J Table B-2.Alternative Results (continued)
-,Alternatives,Results Unit
___l 17 18 19 20
-,
~j Total benefits (thousand 86,847 525,616 98,998 849,079
dollars)11
Net benefits (thousand 47,753 24,150 31,796 52,660
dollars)
BIC (ratio)2.22 1.05 1.47 1.07
Roads built:
n Length (mlles)423.45 413.66 226.83 319.50lCost(thousand -0- -0-
11,697 16,905
dollars)21
rr LP units accessed (map no.)All All 1,2,3,4,All
'-'except except 5,6,8,13,except
LP Unit LP Unit 14,15,16,LP Unit #
4 #40 #11,17,18,19,11,12,22,
U 28,39 20,21,27,23,25,33,
31,32,36,39,40,42,
n 37,43,44,45
LJ 46,47,49
D Acres in production:
Agriculture (ac/yr)-0-219,528 -0-271,576
L1 Timber (ac/yr)9,434 -0-8,591 6,812
0 Commodities produced:
Barley (thous.bu.)-0-12,623 -0-14,782
Spruce sawlogs (MBF)13,259 -0-12,074 9,575
n Cottonwood sawlogs (MBF)12,107 -0-11,025 8,743
Ii Fuelwood (cords)65,144 -0-59,320 47,041
l.J
Annual employment:
0 Agriculture (person years)-0-190.6 -0-235.7
Timber (person years)79.6 -0-90.6 63.9
"U 11 All dollar figures are 1983 values.
r,y Includes overhead and present value of O&M costs.t
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Table -B~2.Alternative Results (cont1nued)
II All dollar figures are 1983 values.
y Includes overhead and present value of O&M costs.
-Alternatives
(ratio)1.09 1.32 1.09
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1.07
235.7
57.5
52,466
All
except
LP Unit #
11,12,22,
23,25,33,
39,40,42,
45
319.50
16',905
14,782
9,575
··8,743
47,041
271,576
6,812
849,079,
23
237.4
57.6
14,884
9,603
8,769
47,182
273,512
6,833
All
except
LP Unit #
11,12,22,
23,25,33,
39,40,45
22
24.9
74.6
28,744
8,841
1,581
12,427
11,347
61,054
All
except
LP Unit #
9,11,12,
22,23,24,
25,28,29,
30,33,34,
39,40,42,
45
21
Unit
(thous.bu.)11,529
(MBf)9,575
(MBf)8,743
(cords)47,041
(person years)181.9
(person years)52.2
(ac/yr)209,616
(ac/yr)6,812
(map no.)All
except
LP Unit #
11,12,22,
23,25,33,
39,40,42,
45
(miles)319.50 249.20 323.21
(thousand 16,905 -12,519 17,130
dollars)y
(thousand 679,506 180,178 815,783
dollars)II
(thousand 53,898 43,333 70,394
dollars)
Annual employment:
Agriculture
Timber
Acres in production:
Agriculture
Timber
Net benefits
B/C
Roads built:
Length
Cost
Commodities produced:
Barley
Spruce sawlogs
Cottonwood sawlogs
fuelwood
LP units accessed
Resul ts
Total benefits
f"
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~79 -[
[
Table B-2.Alternative Results (continued)
!!All dollar figures are 1983 values.
y Includes overhead and present value of O&M costs.
-80 -
Total benefits (thousand 158,113
do11~q)II
Net benefits (thousand 26,350
dollars)
BIC (ratio)1.20
Roads built:
Length (miles)224.39
Cost (thousand 11,586
dollars)y
LP units acc~ssed (map no.)All
except
LP Unit #
1,2,3,4,
5,6,8,13,
14,15,17,
18,19,20,
21,27,31,
32,36,37,
43,44,46,
47,49
Acres in production:
Agriculture (ac/yr)21,800
Timber (ac/yr)8,568
Alternatives
18.9
72.3
25
1,199
12,042
10,996
59,166
Unit
(thous.bu.)
(MBF)
(MBF)
(cords)
(person years)
(person years)
Annual employment:
Agriculture
Timber
Results
Commodities produced:
Barley
Spruce saw10gs
Cottonwood saw10gs
Fue1wood
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APPENDIX C
A Methodology for Estimating Road Costs in the Sus1tna River Basin
The information presented here was developed at the request of the Alaska
Department of Natural Resources.
All costs shown are rough estimates only and are not meant to be used as a
substitute for "on the ground"reconnaissance and subsequent detailed design
and cost work.The purpose of this information is to enable planners and
others to identify the more desirable routes of access by means of
establishing relative costs among route selection alternatives.
This paper is divided into four sections as follows:
1.Initial Construction
2.Associated Costs
3.Operation.Maintenance.and Replacement
4.Total Cost Summary (Example of route selection process)
Initial Construction
Initial construction costs include those costs incurred "up front"for actual
on-the-ground construction of the road.These costs are addressed here in the
following eight categories:
1.cut and f1l1
2.cut and waste
3.backfill
4.surface material
5.clearing
6.seeding
7.culv,erts
8.bridges
The first six are largely a function of slope and soil drainage.while the
latter two.culverts and bridges.are a function of drainage patterns and
slope.Engineering quantity and cost estimates have been made for
construction of gravel roads of varying widths on four types of soil and five
slope categories;"this information is provided in Table 1.1/To actually
estimate the total initial construction cost of various routes.it is
necessary to evaluate each route on a case-by-case basis to determine culvert
and/or bridge requirements.Once this determination has been made.bridge and
culvert costs can be estimated and added to costs provided in Table 1 to
arrive at total initial construction costs.Criteria for estimating bridge
and culvert requirements are presented in Table 2.
1/Basic data used to develop this table are found in Notes to Appendix B of
The Sus1tna Cooperative River Basin Study Economic Development Analysis;
Talkeetna Subbasin.1983.
-81 -
Table 1
-
Road Cost!/as FunctIon of Top W1dth
So11 :18'24'I 32'36'40'
Dra1nage Percent :Cost Per:Cost Per::Cost Per:Cost Per:Cost Per:
Category Slope .'l.F.:H11e'l.F.:HHe :l.F.:HHe l.F.:H11e l.F.:HHe
0-3 21.43 113,100 28.57 150,800 38.09 201,100 42.86 226,300 47.62 251,416
4-7 35,00 184,800 46.66 246,400 62.21 328,500 69.99 369,500 77.77 410,600
Well Dra1ned 8-12 55.,3~292,300 73.81 389,700 98.41 519,600 110.72 '584,600 123.02 649,500
13-20 155.33 820,100 207.10 1,093,500 276.13 1,458,000 310.65 1,640,200 345.H 1,822,500
21-30 233.27 1,231,600 311.02 1,642,200 414.69 2,189,600 466.53 2,463~300 518.37 2,737,000
-
0-3 52.27 276,000 69.69 368,000 92.92 490,600 104.54 551,900 116.15 613,300
4-7 63.18 333,600 84.24 444,800 112.32 593,000 126.36 667,200 140.40 741,300
Poorly Dra1ned 8-12 70.37 371,600 93.83 495,400 125.11 660,600 140.75 743,100 156.38 825,700
~
,13-20 198.28 1,046,900 264.37 1,395,900 352;49 1,861,200;396.56 2,093,800 440.62 2,326,500
21-30 294.52 1;555,100 392.69 2,073,400 523.59 2,764,500 589.04 3,110,100 654.48 3,455,700
0":3 57.79 305.100 77.05 406,800 102.73 542,400 115.58 610,200 128.42 618,000
Shallow Peat
4-7 79.37 ,419,000 105.82 558,700 141.09 745,000 158.73 838,100 176.37 931,200
Deep Peat 0-3 110.35 '582.600 147.13 776.800 196.l7 1.035.800 220.70 1,165,300 245.22 1,294,700
11 Dollars -projected 2nd half.1983.
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Table 2.Br1dge and Culvert S1ze Requ1rements 11
11 It 1s emphas1zed that th1s 1s a "short-cut"method of determ1n1ng
requ1rements.Other factors.1nclud1ng d1scharge and f1sher1es 1mpact.
should always be cons1dered pr10r to any actual construct1on.
Eng1neers have assumed that road cross1ngs at streams w1th a dra1nage area 1n
excess of 25 square m11esw111 requ1re br1dge construct1on.Br1dge costs are
est1mated to be $lOl.50/sq.ft.S1nce f1xed costs are such a large port1on of
total br1dge costs.and s1nce any planned route may be upgraded 1n the future.
1t 1s un11kely that any br1dge less than 32 feet 1n w1dth would be
constructed.As a result.br1dge costs per 11near foot for roads of vary1ng
w1dth are est1mated to be as follows:
Dra1nage Area of :Culvert ·Cost·Stream at Proposed :or :Per Lf
Road Cross1ng ·Br1dge :of Culvert·(Square M11es):Requ1rements ·(dollars)·····
Less than 0.3 one 2 1 d1ameter culvert 36.25/Lf
0.3 -1.0 one 4 1 d1ameter culvert 108.75/Lf
1.0 -2.0 one 6 1 d1ameter culvert 217.50/Lf
2.0 -5.0 one 8 1 d1ameter culvert 290.00/Lf
5.0 -10.0 two 8 1 d1ameter culverts 580.00/Lf
10.0 -20.0 three 8 1 d1ameter culverts 870.00/Lf
20.0 -25.0 four 8 1 d1ameter culverts 1.150.00/Lf
Greater than 25.0 br1dge 101.50/ft.2
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Road W1dth
18 1
24'
32 1
36 1
40 1
-83 -
Br1dge Cost
per L.f.of road
$3.248
$3.248
$3.248
$3,654
$4.060
Culverts would be necessary a~many road crossings ~here stream drainage areas
are less than 25 square miles.Table 2 provides information concerning
culvert she (dtameter)requirements and unit costs"as a function of slream
drainage area~Table 3 indicates the~lengthof culverts requ1red.for varying
road widths given alternative slope conditions.Table 4 is a product of
Tables 2 and 3 and shows total culvert costs'as a function of road width,.
slope,and stream drainage area.
Table 3.Culvert length Requirements
Culvert length as Function of Road Width
Percent :18':24 1 :32':36':40 1
Slope ·Width .Width :Width :Width .Width·..·::.:·.
0-3 46'52 1 60 1 64 1 68 1
4 - 7 66 1 72'80 1 84'88 1
8 -12 81 1 87 1 95 1 99 1 103'
13 -20 223'229 1 .237'241 1.245 1
21 -30 316 1 322'330'334 1 338 1
-84 -
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C Table 4.Culvert Costs by Dra1nage Area and Road W1dth
r ······Road W1dth··L--'Percent :Dra1nage Area :18 1 .24 1 :32 1 ·36 1 :40 1.·.
Slope ·at Road Cross1ng :W1dth :W1dth .W1dth ·W1dth :W1dth·.·
C ·(Square Hlles)·
Less than 0.3 $1,668 $1,885 $2,175 $2,320 $2,465
C 0.3 -1.0 5,003 5,665 6,525 6,960 7,395
1.0 -2.0 10,005 11,310 13,050 13,920 14,790
0-3 2.0 -5.0 13,340 15,080 17 ,400 18,560 19,720
[5.0 -10.0 26,680 30,160 34,800 37,120 39,440
10.0 -20.0 40,020 45,240 52,200 55,680 59,160
20.0 -25.0 53.360 60.320 69.600 74.240 78.880
C Less than 0.3 2,393 2,610 2,900 3,045 3,190
0.3 -1.0 7,178 7,830 8,700 9,135 9,570
1.0 -2.0 14,355 15,660 17 ,400 18,270 19,140
0 4 - 7
2.0 -5.0 19,140 20,880 23,200 24,360 25,520
5.0 -10.0 38,280 41,760 46,400 48,720 51,040
10.0 -20~0 57,420 62,640 69,600 73,080 76,560
20.0 -25.0 76.560 83.520 92.800 97.440 102.080
0 Less than 0.3 2,936 3,154 3,444 3,589 3,734
0.3 -1.0 8,809 9,461 10,331 10,766 11 ,201
C 1.0 -2.0 17,618 18,923 20,663 21,533 22,403
8 -12 2.0 -5.0 23,490 25,230 27,550 28,710 29,870
5.0 -10.0 46,980 50,460 55,100 57,420 59,740
0 10.0 -20.0 70,470 75,690 82,650 86,130 89,610
20.0 -25~0 93.960 100,920 110.200 114.840 119.480
Less than 0.3 8,084 8,301 8,591 8,736 8,881
[}0.3 -1.0 24,251 24,904 25,774 26,209 26,644
1.0 -2.0 48,503 49,808 51,548 52,418 53,288
13 -20 2.0 -5.0 64,670 66,410 68,730 69,890 71,050
n 5.0 -10.0 129,340 132,820 137,460 139,780 142,100
10.0 -20.0 194,010 199,230 206,190 209,670 213,150u20.0 -25.0 258.680 265.640 274.920 279.560 .284.200
0 Less than 0.3 11 ,455 11,673 11,963 12,108 12,253
0.3 -1.0 34,365 35,018 35,888 36,323 36,758
-1.0 -2.0 68,730 70,035 71,775 72,645 73,515
C 21 -30 2.0 -5.0 91,640 93,380 95,700 96,860 98,020
5.0 -10.0 183,280 186,760 191,400 193,720 196,040
10.0 -20.0 274,920 280,140 287,100 290;580 294,060
U 20.0 -25.0 366.560 373.520 382.800 387.440 392.080
U
C -85 -
C
Associated Costs
Once total initial construction costs have been estimated,additional costs
must be included to account for associated activities.These costs are
expre~se~al a function (~ercentage)of total initial construction cost and,
are as follows:
-86 -
11 See Notes to Appendix B of The Susitna Cooperative River Basin Study
Econom1c Development Analysis;'Talkeetna Subbasin,1983 for derivation of
annual O&H cost.
It is 1~portant to note that the pe~centages provided above are estimates
from the Alaska Department of Transportation.Depending 'on the agency or
authority 1,nvolved,these costs may vary greatly.At present,for example,
the Matanuska-Susitna Borough estimates its total associated costs to be
roughly 35%of initial ·con~truct1on.
Operation,Maintenance,and Replacement (OM&R)
In contrast to initial costs (both construction and associated)wh1ch are
.incurred at one p01nt in time,OM&R costs occur on a continual or repetitive
schedule.Generally,O&H takes place on an annual basis,while replacement
occurs at various 1ntervals depending uPQn the II 11 fell of the item to be
replaced.
For this analys1s,the evaluation period is assumed to be 50 years.During
this period O&M will occur annually and 15 est1mated to be
$4,727/mlle/year]!.The expected lHeof culverts and bridges is assumed
to be 25 and 50 years respectively.In order to put O&Hand Replacement
costs on a par with 1n1t1al costs,it is necessary to determine their
"Present Value"(1nit1al construction and associated costs discussed in
prev1~us sect10ns are already on a "present value"bas1s).Present value is
Item
1.Engineering services -design,soil testing,quantity
and cost computations,survey work,etc.
-2.Mob1l1zat1on -transportation of construction equipment
to the work site and maintaining it at this location.
3.Contract Adm1n./Construct1on Inspection -administration
'of contract,meals and lodging,on-sHe inspection of
construction activities,and materials.
4.Contingencies -unforeseen prpblems in construction
and/or other associated items.
Tot.al
Percent
20
10
12
10
52
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Example 1
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a function of both discount rates and time.Since the time period is
known--every year for O&M and once every 25 years for cU1vertsl/.only the
discount rate i simportant.
The following alternative factors can be applied to annual O&M costs and
culvert costs to determine their present value.
Annual Discount Rate (%)
Item :8 :9 .11 .12 :13 .14 .15. . . .
--
o &M~/12.233 10.962 9.915 9.042 8.304 7.675 7.133
Replacement ~I 0.146 0.116 0.092 0.074 0.059 0.047 0.038
(CuJverts)
To illustrate how those figures should be used.the following examples are
provided:
-The present value of annual O&M per mile.given a 10%discount
rate.is $4.727~/x 9.915 or $46.868.
Example 2 -The present value of replacing a 4 ft.diameter cU1vert1/•
72 ft.in length.given a 10%discount rate.is $7.830 (see
Tables 2.3.and 4)x 0.09Z or $720.
It is important to note that no associated cost percentages should be
applied to O&M or rep1aceme~~costs because generally these are part of an
on-going program.. .
II Since the life of a bridge is equal to the evaluation period (50 years)
no bridge replacement C05tS need be factored into the analysis.
~I Present value of a constant annuity of 1 per year for 50 years.
~I Present value of 1.25 years hence.
!I See Notes to Appendix B of The Susitna Cooperative River Basin StUdy
Economic Development Analysis;Talkeetna Subbasin.1983 for derivation of
Annual O&M cost.
11 Size of culvert required where road width is 24 1 •terrain is 4-7%slope.
and stream drainage area is 0.3-1.0 square miles above road crossing.
-87 -
Total Cost Summa ry1l
The information presented in the previous sections will enable planners and
others to estimate relative costs of alternative access routes.The example
provided on the following pages illustrates a typical situation and can serve
as a guide to those utilizing the information presented here.
11 Noland rights costs have been addressed in this analysis due to their
high variability.Those using this methodology should.however.be aware
that.depending upon proposed road locat10n.land rights may be an important
factor in the route selection process.
-88 -
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Well-drained soil area ....4-7 percent slope
Deep peat soil area ~0-3 percent slope
Poorly-drained soil area -0-3 percent slope
Well-drained soil area -8-12 percent slope
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Key:
Scale:1 inch
Total road cost example
(j)=
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(j)=
(i)=
~=Proposed route
s§t:=Major stream drainage area =50 mi 2
=Tributary drainage area =3.6 mi 2
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1 at 20,880 (Table 4)=20,880
Subtotal =$2,905,416
ROUTE A Ghen:
1.Width of Road =24 feet
2.Miles of Road in 1 =2.0
3.Miles of Road in 2 =1.9
4.Miles of Road in 4 =2.0
5.length of bridge required at major road crossing =42 feet
6.Discount Rate =10"
(a)2.0 +1.9 +2.0 =5.9 miles
(b)5.9 miles x 4,727/m11e annually =$27,889
(c)Present value =9.915 x 27,889 =
COMPUTATIONS:
I.Initial Construction
Road
2.Qx 246,400 =492,800
1.9 x 776,800 =1,475,920
2.0 x 389,700 =779,400
Bridge
42 x 3,248 =136,416
Culverts
II.Associated Costs
2,909,766 x 52"=
III.OM
-90 -
$1,510,816
$276,522
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ROUTL!Given:
1.Width of Road =24 feet
2.Miles of Road in 1 =1.3
3.Miles of Road in 3 =3.35
4.Miles of Road in 4 =1.3
5.Length of bridge required at major road crossing =42 feet
6.Discount Rate =10%.
1 at 20,880 (Table 4)=20,880
Subtotal =$2,217,026
42 x 3,248 =136,416
3.35 x 368,000 =1,232,800
$4,694,675
$1,921
$1,152,854
GRAND TOTAL (ROUTE A)=
-91 -
320,320
506,610
1.3 x 246,400 =
2,221,376 x 52%=
Road
20,880 x .092 =
1.3 x 389,700 =
Bridge
Culverts
COMPUTATIONS:
I.Initial Construction
IV.Replacement
II.Associated Costs
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III.O&H
(a)1.3 +3.35 +1.3 =5.95 miles
(b)5.95 miles x 4.727/mile annually =28.126
(cj Present value
9.915 x 28.126 =$278.866
IV.Replacement
20.880 x .092 =$1.921
GRANO TOTAL (ROUTE B)=$3.650.667
...92 -
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APPENDIX D
Computer Models for Land Suitability:
1)Moderate/high density residential
development
Z)Moose habitat
3)Roads
Excerpted from:Final Report -
Computerized Geographic Information
System.Talkeetna and Beluga Subbasins.
Susitna River Basin.Alaska
(ESRI 1982)
-93 -
MODEL OUTLINE
LAND CAPABILITY fOR MODERATE/HIGH DENSITY RESIDENTIAL DEVELOPMENT
Consideration Specific Data Class Value Value
(incidence)(proximity)
Landform Type Glacial
Moraine H
T111 H
Drumlin
Drumlin/Drumloid H
Rock Drumlin NR
fluviog1acial
Outwash H
Abandoned Outwash Channel H
Remnant Subglacial
Stream Valley H
Kame Complex HEsker..H
Creva~se filling H
Side Glacial Drainage
Channel H
flute H
Aeolian
Dune L
Littoral
Longshore Bar U
Beach U
Barrier Spit U
Delta L
Tidal flaf U
Coastal Plain NR
fluvial
Active Channel U
River Bar U
floodplain
Active U
Abandoned NR
Alluvial Plain H
Alluvial fan/Cone H
Lacustrine Deposit H
Mass Wasting
Colluvium U
Talus U
Landslide Deposit U
Rock Glacier U
Mine Tailings U
H =high
M =moderate
L =low
U =unsuitable
N'R =not rated
-94 -
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-95 -
MODEL OUTLINE
LAND CAPABILITY FOR MODERATE/HIGH DENSITY RESIDENTIAL DEVELOPMENT (continued)
Ratings are scanned within each general category encompassing more than one
factor and the most severely constraining rating is used to provide the
overall rating for the category.In effect,each general consideration -
landform,soils,water availability,etc.,-has a single rating when
summation begins.The following summation procedures are used:
-96 -
GE =greater than or equal to ...
EQ =equal to .•.
GT =greater than ...
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Value
(proximity)
NR
L
NR
Value
(incidence)
GE1H and Not EQ ML or U
EQl or 2M and Not EQ L or U
GT2M or EQl or 2L and Not EQ U
GT2L or GE1U
Limitations for Local
Roads and Streets
Slight H
Moderate H
Severe M
Drainage
Excessively Drained M
Somewhat Excessively
Drained H
Well Drained H
Moderately Well Drained M
Somewhat Poorly Drained L
Poorly Drained U
Very Poorly Drained U
Ice U
Non Glacial
Stream (GE2nd Order)
LEl Mile Distance
GTl Mile Distance
If Potential Well
Yield Area 1
If Potential Well
Yield Area 2 or 3
Specific Data Class
MODEL SUMMATION RULES
Water Availability
Consideration
High Capabllity
Moderate Capability
Low Capability
Incapable
Closed Forest (Black Spruce
Mountain Hemlock)
Black Spruce,Short Stands 4
Black Spruce~Tall Stands 4
Mountain Hemlock,Tall Stands 1
Open Forest-Woodland
Coniferous Forest,White
Spruce,Short Stands 2
Deciduous Forest~Mixed Forest,
Medium-Aged Stands 2
Coniferous Forest,White
Spruce,Tall Stands 2
Deciduous Forest,Mixed Forest,
Old Stands .3
Cottonwood-Medium Aged Stands 5
Cottonwood-Old Stands 3
Primary Vegetation Closed Forest
Coniferous Forest,White
Spruce,Short Stands 3
Deciduous Forest,Mixed
Forest,Young Stands 2
Deciduous Forest,Mixed
Forest,Medium-Aged Stands 1
Coniferous Forest,White
Spruce,Tall Stands 1
Deciduous Forest,Mixed
Forest,Old Stands 2
Cottonwood-Young Stands 1
Cott9nwood~Medium Age Stands 3
Cottonwood-Old Stands 3
,..,
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MODEl OUTLINE
MOOSE HABITAT
Consideration Specific Data Class Value
(incidence)
Value
(prOi1iii1ty)
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Open Forest-Woodland (Black Spruce)
Black Spruce,Short Stands 5
Saltwater Wetland
Salt Grassland 9
Low Shrub 9
Tidal Marsh 9
Tall Shrubs
Alder 3
Alder-Willow 1
-97 -
-98 -
MODEl OUTLINE
MOOSE HABITAT (continued)
MOD/HIGH =moderate to high value for ...
WR =winter range
S/S/F =spring.summer.fall
MODEL SUMMATION RULES
VALUES 1-4 =LEVEL 1 MOD/HIGH WR.(S/S/F)RANGE
VALUES 6-7 =LEVEL 2 MOD/HIGH (S/S/F)RANGE.NO WR
VALUES 5.8-10 =LEVEL 3 LOW TO NO HABITAT
VALUES 11 =LEVEL 4 WATER
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Value Value
(incidence)(proximity)
6
6
8
6
7
8
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7
10
10
10
10
10
11
Barren
Mud Flats
Rock
Low Shrub
Willow Resin Birch
Water
Cultural Features
Cultural Influences
Fresh Water Wetlands
Sphagnum-Bog
Sphagnum-Shrub Bog
Permanent Snow and Ice
Snowfield
Glacier
Grassland
Upland Grass
Tundra
Sedge-Grass
Herbaceous
Shrub
Mat and Cushion
Specific Data ClassConsideration
Glacial
Moraine 4
Till 4
Drumlin
Drum11n/Drum101d 3
Rock Drumlin 7
Fluv1og1ac1a1
Out\!lash 3
Abandoned Outwash Channel 3
Remnant Subglacial
Stream Valley 4
Kame Complex 2
Esker 1
Crevasse Filling 1
Side Glacial Drainage
Channel 3
Flute 3
Aeolian
Dune 7
Littoral
Longshore Bar 8
Beach 8
Barrier Spit 8
Delta 9
Tidal Flat 9
Coastal Plain 9
Fluvial
Act he Channel 8
River Bar 6
Floodp1a in
Active 7
Abandoned 4
Alluvial Plain 3
Alluvial Fan/Cone 2
Lacustrine Deposit 9
Mass Wasting
Colluvium 10
Talus 10
Landslide Deposit 10
Rock Glacier 10
Mine Tailings 5
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MODEl OUTLINE
ROAD SUITABILITY
TALKEETNA SUBBASIN
Consideration
Landform Type
(Rating 1 to lOt
1 is best)
Specific Data Class
-99 -
Value Value
(incidence)(proximity)
MODEl OUTLINE
ROAD SUITABILITY (cont1nued)
TALKEETNA SUBBASIN
Considerat10n
Slope Grad1ent
(Rat1ng 1s 1 to 40.
1 1.s best)
Geolog1c·Hazard
(Rat1ng 1s 1 to 10.
1 1s best)
S011 Character1st1cs
(Rat1ng 1s 1 to 10.
1 1s best)
SpecH1c Data Class Value Value
(1nc1 dence)(prox1mHy)
Tecton1c Up11ft
Upland Va lley 7
Mounta1n S1deslope 10
Mounta1n R1dgetop 10
Waterbody 10
Ice and Snow 10
Slope Grad1ent
Level or Nearly Level 1
Gently Slop1ng 2
Undulat1ng 2
Slop1ng (Moderately)3
Rol11ng 3
Strongly Sl~p1ng 5
H1l1y 5
Moderately Steep 15
Steep 20
Very Steep 30
Extr.emely Steep 30
Water 30
Ice 30
Pr1mary Potential
Flood Zone 10
Pr1mary Flood Zonel
Wave Zone 10
Secondary Potential
Flood Zone 5
Secondary Flood Zonel
Wave Zone 5
Outburst Flood Zone 10
Catastroph1c Wave Zone 10
Lands11de Zone 10
Vary1ng Part1cle She 5
Unstable Ground 10
Avalanche Track 10
L1m1tat10ns for Local Roads
and Streets
S11ght 1
Moderate 5
Severe 10
Water 10
-100 -
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MODEl OUTLINE
ROAD SUITABILITY (continued)
TALKEETNA SUBBASIN
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Cons1derat1-on
(Rating is 1 to 15 t
1 is best)
(Rating is 1 to lOt
1 is best)
(Rating is 1 to 15 t1isbest)
Vegetation Cover
(Rat1ng is 1 to 40 t
1 ts best)
Specific Data Class Value Value
(incidence)(proximity)
Drainage
Excessively Drained 1
Somewhat Excessively
Drained 1
Well Drained 1
Moderately Well Drained 2
Somewhat Poorly Drained 5
Poorly Drained 10
Very Poorly Drained 15
Ice 15
Water 15
Source Road F1l1
Good 1
Fair 5
Poor 10
Water 15
From Good
If ~1/2 Mlle 1
If >1/2 Mile <1 Mile 2
If >1 Mile <l Miles 4
If >1 Mile <·3 Miles 6
If >3 M11es~4 Miles 8
If >4 Miles <5 Miles 10
If >5 Mlles 10
Closed Forest
(GE 50%Crown Cover)10
Open Forest (GE 10%to
LT 50%Crown Cover)6
Non Forest (LT 10%Crown Cover)
Salt Water Wetland
Grassland 40
Low Shrub 40
Tidal Marsh 40
Tall Shrub
Alder 4
Alder-Willow 4
Low Shrub
Willow-Resin Birch 2
Gr~~(~_I,.-1
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-101 -
MODEL OUTLINE
ROAD SUITABILITY (continued)
TALKEETNA SUBBASIN
-102 -
ARLIS
Alaska R~ces
Library i':~ervlce
J\li~:~.~~~a
Less than 10
11 -15
16 -30
31 -60
61 -100
101 -150
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Value
(prox1mity)
Value
(incidence)
Tundra
Sedge-Grass 20
Herbaceous 15
Shrub 20
Mat-Cushion 20
Freshwater
Sphagnum Bog 30
Sphagnum-Shrub Bog 30
Cultural
Cultural Influence 1
Barren
Mud Flats 40
Rock 40
Snow
Snow Field 40
Glacier 40
Water
Lake GE 40 Acres 40
Lake GE 10 Acres and
LT 40 Acres 40
Stream or River Gf 165 Feet
Wide and LT 550 Feet Wide 40
R1ver GE 600 Feet W1de 40
Stream or R1ver LT 165 Feet
Wide 40
Specific Data Class
MODEL SUMMATION RULES
H1gh
Moderate H1gh
Moderate
Low
Very Low
Extremely Low
Consideration
ASD-WP 1720-86