HomeMy WebLinkAboutScammon Bay Small Hydropower Study and Environmental Assessment 1981..
Scammon ~:1l\'; ay
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Small Hydropower Study and
Environment Assessment
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'-------:~my Corps
of Engineers
Alaska Distnct
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SUtf1ARY
Like most isolated villages in Alaska, Scannon R~ has been plagued
\'Iith ever i ncreasi ng electrical costs. Although at one time relati vely
inexpensive, diesel fired electrical generation costs h~veskyrocketed
since Sca~on B~ became electrified in 1974.
This study considered various alternatives that could either supple-
ment or replace diesel generation. Two alternatives '1ereidentified that
could have a significant impact on electrical generation, '-lind generation
and hydropower, neither of ,.,hich could totally eliminate the use of
diesel.
Wind generation appears to have good potential during the ,,,inter
months when high winds of long duration occur; however, wind potential
duri n9 the Sllr.\ll1er nonths appears relati vely poor. The exact extent of
Scammon Bay's ,,,ind resource has never been assessed, making detailed
evaluation difficult. Even i.f this infomation were available, the state-
of~the-art in wind generation is such that no units are currently
comercially available that could r.Jeet the village's need for 60 cycle AC
current unless they are induction generators, ,.,hich would only rneet a'
very small portion of the energy needs at any one tir.Je (approximately
15-25 percent). .
Hydropotler generation, the selected plan, 'fOuld totally replace
diesel for approximately five mOnths of the year and partially. replace it
for, another three nonths. The hYdropm1er systeM would consist of a small
dam, 3500 ... foot penstock, and a pO'1erhouse t/ith a 100-kilowatt turbi ne-
generator unit. The estioated first cost in October 1981 dollars is
$1,130,000, with operation and maintenance estimated at $20,000 annually.
This system could produce an es~imated 432,000 kWh of energy during the
months of April through Noveober. Approximately 55 percent would be
us~ble during 1983, the first year of operation.
If a cot1r.1ercial1y vi'able wi nd systern becomes avail able that could
function as an i ntergal part of the ScamonRay sy stel':1 , it appears that
it could COMplement .thehYdropower system. Wind potential is greatest
duriog· the \11 nter tlhenihe, tiydrosystem '-IOU 1 d be shut down and 1 east ,i n
the sun;ner ,.,hen hydropo~r 'p()tential is greatest. . .
i
(
SCAMMON BAY
PERTINENT DATA SHEET
SCArf10N BAY
GENEI'tAL DATA
Project"Insta11ed Capacity
Nunber of Units
Type of Turbi ne .
Average' Annual Energy (kWh)
Estinated Usable Energy (1983)
Estinated Usable Energy (1990)
Dependab1 e Capaci ty
Gross Head
Oesign Head
ECONoruc DATA
Project InvestnentCost
Project Annual Cost
Project Annual Benefit
Net Annual Benefit
Benefit Cost Ratio
iii
100 kW
1
Inpulse
432,000 kWh'
239,000
306,000
o
485 Ft.
430 Ft.
$1,130,000
$108,400:
~
$125,300
$16;900
1. 16 to 1
TABLE OF CONTENTS
INTRODUCTION •••••••••••••••••••••••••••••••••••••••••••••••••••••• 1
, .1 AlJTHORITY ••• e,e ••••••••• ~ •••••••••••••••••••••••••••••••• 1
1.2 SCOPE OF THE STUgY •••••••••••••••••••••••••••••••••••••• 1
1.3 STUDY PARTICIPANTS •••••••••••••••••••••••••••••••••••••• 1
1.4 STUDlES BY OTHERS ••••••••••••••••••••••••••••••••••••••• 2
EXISTING CONDITIONS ••••••••• ~ ••••••••••••••••••••••••••••••••••••• 3
2.1 COt1r1IJNITY PROFILE •••••••••••••••••••••••••••••••••• · ••••• 3
2.2 NATURAL SETTI NG ••••••••••••••••••.•••• , •••••••••••••••••• 6
2.3 ELECTRICITY USE .••...•.•................................ 9
PJWB LEns, NE EDS, AND STUD Y OBJ E CTI VES ............................ 1 4
3.1 POWER SUPPLY AND FUTURE DEr1AND ••••••.••••••••••••••••••• 14
FORMULATION AND EVALUATION OF ALTERNATIVES •••••••••••••••••••••••• 19
4.1 ALTERNATIVES •••••••••.•.••.•••.••.•.••.......••••••••.• 19
4.2 Sur,1t1ARY OF BEST ALTERNATIVES (SOA) ••••••••••••••••••••• 28
4.3 NED PLAN ............••.......•......................... 32
4.4 EO PLAN •••••••••••••• ~ •••••••••••••••••••••••••••••••• ~3l,
4.5 SELECTED PLAN •••••••••••••••••••••••••••••••• · •••••••• :.32
CONCLIIS IONS AND RECOt"1ENDATIONS •••••••••••••••••••••••••••••••••• 33
5.1 CONtLuSIONS •••• ~ •• ~ •••••••••••••••••••••••••••••••••••• 33
5.2 RECO~1t1ENDATION •••••••••••••••••••••••••••• ~ •••••••••••• 33
TECHNICAL
T .1
T.2
T.3
. T.4
T.5
T • .6
T.7
T.8
T.9
T.10
T.11
T.12
" ,I "
ANALYSIS., •• ~ ••••••••••••••••••••••••••••••••••••• ~ •••• 35
GENERAL •••••••••••••••••••••••••••••••••••••••••••••••• 35
HYDROLOGY ••• ' ••••••••••••••••••••••••••••••••••••••• ~ ••• 35
GEOLOGY ••••••••••••••••••••••••• ~ ••••••• w •••••••••• ~ ••• 45
DAU:AND SPILLWAY, AND INTAKE. •••••••••••••••••••• ~ ••••• 45
PENSTOCK •••••••••• *.* ••••••••••••••••••••••••••••• e' •••.•• 47
POWERHOUSE ...•••..•..••......••..••.••..•..••••••.•••.• 48
TRANS~lISS ION SYSTEt1 •••••••••••••••••••••••••••••••••••• 50
ALTERNATIVEpESIGNS CONSIOERED ••••••••••••••••••••••••• 50
CONSTRUCTION PROCEI'IURES •••••••••••••••••••••••••••••••• 51
PROJECT OPERATION AND MAINTENANCE •••••••••••••••••••••• 51
PROJECT COST •••••••••••••••••••••••••••••••••••••• ~ •••• 53
PROJECT ECONotHCS •••••••••••••••••••••••••••••• · •••••••• 54
FINDING OF NO SIGNIFICANT In'PACT. ~ ••••••••• ~ ••••••••••••••••• ye11ow
ENVIRONnENTAL ASSESSr1ENT ••••••••••••••••••••••••••••••••••••• ye 11 ow
FISH AND lHLDLIFE COORDINATION ACT REPORT •••••••••••••••• Appendix A
iv
a ..
INTRODUCTION .
1 • 1 AUTHOR ITY
The evaluation of small scale hydroelectric syst~s was authorized by
a United States Senate Resolution dated 1 October 1976. Tbat resolution
directed the lJ.S.Arqy Corps of Engineers to detemine the feasibility of
install i n9 small. pr~packaged hydroelectric units in i sol ated communities
throughout Alaska •.• The full text of the resolution reads as foHolls: ... , '
RESOLVED BY THE COf.1ITTEE ON PUBLIC WORKS OF THE UNITED STATES
SENATE,That the Board of Engineers for Rivers and Harbors' be, and is
hereby requested to; review the reports. of the Chief of Engineers on
Rivers,and Harbors.,in Alaska, puhlishedas House nocur.aent Numbered
414, 83rd Congress, 2nd Session; Southeastern Alaska, published as
House Docur.aent Nut:1bered 501, 83rd Congress, 2nd Session; Cook Inlet
and Tributaries, Alaska, published as House Document Numbered 34,
85th Congress, 1st Session; Copper River and Gulf Coast, Alaska,
publ ished as House Document NUr.1bered 182, 83rd Congress, 1 st Session,
. Tanana River Basin, Alaska, puhlished as House nocur.1ent Numbered 137,
84th Congress, 1st Session; South''#estern Alaska, published-as House
nOcur.leht NUr:1bered 390, 84th Congress, 2nd Sessi on; Not hue stern.
Ala~ka, publi shed asHouse Document NlJr.'Ibered 99, 86th Congress, 1 st
Session, Yukon and KUskm-,in River Basins, Alaska, published as House
Document Numbered· 218, 88th Congress, 2nd Session; and other ,
pertinent reports,Hith a vie,., to detemining the advisab11ity of
r.1Odifying the existing plans with particular reference to the
feasibility of installing 5 ru~ or less prepackaged hydroelectric
plants to service .isolated connunities.
. .
1 • 2 . SCOPE OF THE ST~nY
This interir.1 studyuas undertaken to detemine if econonically and
environmentally feasible alternatives exist that could meet orsuppiement
the futureelectricar'energy . needs of Scamon Bay. Potentially feasihle
alternatives ·\'fere .e.valu.atedin sufficient detail to allow expedited
inple~ntation. This studY.considered only electrical enerQ..,!needs si nee
total energy needs \'#ere, evaluated in the Alaska Potier Authority's (APA)
energystudy~ recently conpleted by fJorthern Technical Services (NORTEC).
A sumary of findings forthe'Scamon Bay portion of theAPA study is
given llnder Section L 4 STUDIES BY OTHERS.
1.3 STUDY )ARTICIPANTS
A nultidisciplinary tean conposed of the follo\'1ing agencies assisted
the Alaska' District, Corps of Engineers in preparation of this report. ,
-U~S. Fish and Wildlife Service
-U.S. Public Health Service
-U.S. Bureau of Indian Affairs
-Alaska PO''ler Adninistration (Federal)
-Alaska POHer Authority (State)
-Alaska Village Electrical Cooperative
-Northern Technical Services {NORTEC}
The cooperation of the people of Scarnm~n Bay is also gratefully
acknoH1edged.
1.4 STUDIES BY OTHERS
The United State's Departr.1ent of Energy, A1a'ska PO\'fer Administration,
prepared the "S ma 11 Hydroelectric Inventory Of Villages Served By Alaska
Village Electrical Cooperative" in Decel7lher 1979.' This study assessed
the potenti;a1 for hydroelectric deve10pr.1ent at over 40 villages in
,';estern Alaska. SCar.1r.l0n Bay \'las found to be the Most likely village of
those studied to have a feasible hydropo\'1er site. This preliminary
investigation considered tHO potential dave10pment scher.1es, one \'1ith an
installed capacity of 170 ki10\'iatts (k~n, the other,\'1ith 285 kW. These
pre1ir.1inary estir.1ates Here based on an estir.1ated average streal7lf10w at
the damsite of 9 cubic feet per second (cfs}.Subsequent investigatio;ns
and streanf10\l,r.1easurer.1ents hy the Corps of Engineers ;'ndicated an
average annual streamf10\'1 of about 2.5 cfs, well be10\'1 that assumed.
NOn-TEC prepared a draft report for the A1 aska Pouer Authority'
entitted Reconnaissance Stud Of Ener Re uirements And Alternatives,
To iak, 'Go'o neHS ay, ,)car.11710n a, n ra 1n e ruary e
OR study a resse a "energy nee s on a reconnaissance level.
including 'electrical, heating, cooking, and transportation. It projected
future energy needs for electrical and heating purposes and evaluated'
nUl7lerous alternatives to r.1eet these needs. Alternatives determined
\'/orthy of further consideration included energy conservation. direct
\'faste heat capture, hydropO\'1er, and possibly Hind generation. The first
two a1 ternatives, energy co'riser-vati on and \'1aste heat recovery i , related
pril7lari1y to the heating load. Hydropo\'ler and \'1ind \.,ou1d provide
electrical energy, with diesel providing backup in both cases. Other
alternatives considered, but detemined infeasih1e, included Rankine
Cycle \'1aste heat capture, fueJce11s. geothema1. tidal. solar
photovo1taic" stear.1, and,gasification. '
NORTEC'S projected energy der.1and ,for Scalllnon Bay took' into account
the recent addition of a 6,500-square-foot high school and the planned
1981-1982 "addition of 24 housing units by u.S. Depar'tr.1ent of Housing and
Urban nevelopr.1ent (HUn). Ahove that, a conservati ve gro\,/th 'i n energy
demand, of 0.9 percent \'1as usedbegi nni ng in 1982. The o. 9 pe~ent
estir.1atedgrO\,rth ratei s \'/ell be10u the historical grO\1th 'rate for
Scar:1r.1on Bay, but past increases Here largely due to the initial '
acquistion of electrical appliances during electrification •. NORTEe
as'sumed that increasing costs, coupled \'/ith conservation \'1ou1d tel7lper
future gro\'/th;, houever, \'lith, passage of the "Po\-fer Cost Assistance
Progral7l" by the Alaska Legislature in August 1981, pO\'1er costs will be
subsidized (in Scamon Rav) to a level be1o\'1 the 1975 consur.1ercost.
Therefore, the 'NORTEC forecast will be consider the low load grO\1th
scenario.
2
, , ,
EXISTING CONDITIONS
2.1 COt1r1LlNITY .P!lOFILE
Scar:non nay is an ES,kir:lO village located .in,theYukon:"Kuskok\'lim Delta
region of southl'lestern Alaska. The village, orfginal1ynamed r1ariak. was
officially renaned Scamon Ray in honor of Captain Charles M. Scarnnon who
served as marine chief of the \~estern Union Telegraph Expedition in
A1askafron 1856 to 1867. .
2. 1.1 Popul ati on
Prelininary data fron the 1980 census indicate a population of 251 at
Scammon Bay. This represents an average population increase of over 4
percent per year si nce the 1970 census. HO\,/ever, the actual yearly
growth rate has varied considerably as can be seen below:
Table 2.1
HISTORIC POPULATION OF SCN·1MON BAY
Year
1940
1950
1960
1970
1975
1976
1977
1978
.1979
1980 .
;" ."; '.
2.1.2 Government and Services
Population
08
103 .
115
166
165
192
225
193
232
251
ScamonBay \,/as incorporated as a second class city in 1967. The
seven nenber city council selects the to\'m mayor and administrator. In
addition, the city enploys a clerk. secretary/treasurer. police, and
maintenance personnel. These positions are funded through the Compre-
hensive Emp10ynent Training Act (CETA) program. Other government
supported employment sources include the Bureau of Indian Affairs School.
the !lura1 Parent-Child Progran, and seasonal fire fighting for the Qureau
of Land r1anagement.
Scannon Bay's native population is represented hy a 5-nenber
traditional council which is the official tribal governing body for the
village. The council is e1igihle to adninister a variety of Federal
programs, including local health care, employment assistance, college
assistance, social services, etc. .
3
2.1.3 Transportation and Communication
Scar.1r.1on Bay is accessible by air, \'/ater, and \'/inter trail. Fuel and
bul k supplies are barged to the community from June to September. The
Kun P.iver. se~ves approxinately 60 privately o\'1ned boats, providing
transport.ation to fish and berry car.1ps.
'~.' '
. A 2,BOO-foot gravel airstrip north of the city enables daily sched-
uled cOr.1r.1ercial air service. Principal air carriers include Sea Airrno-
tive and Hei n. ScaMMon nay has approxinately 1 nile of gravel road for
use by thefew vehicles in tmm. Sno\'nnach,ines, owned by nearly every
household ~in the comunity, are the r.1ajor fom of transportation in
Hinter.
The cOr.1Dunity r.1enbers have access to one telephone located in the;
conmunity'hall. Television is also available from the Alaska Statewide
Satell ite "ColT.1unications neb/ork.
2. 1.4 Economy
Year-round er.1p10Yr.1ent f n the city is avai 1 able through local govern-
ment and trade. In the trade sector, employers include the airport, four
small stores, and the general store. Some residents also sell handmade
grass baskets, ; vory carved je\'1e1 ry, and other handicrafts.
In addition to the governr.1ent,comercia1 ffshingis the other
primary source of incor.le for Scammon Bay. As of 1979, the Yukon District
had issued 40 gill' net pern4ts to Scar.1r.1on Bay residents. COr.1mercial
species includesalinori and,toa1esser extent herring. Herring are
anticipated to becor.1e a larger portion of the cash economy\'/ith the
.investr.Jent by the Alaska Renewable Resource Corporation in the
construction of approxiMately lO.herring fishing boats at Sca~on Bay.
In addition to theSe conmercial catches, noncash landings include
\'/hi tefi sh, bl ackfi sh, need) ef'i sh, snel t, and toncod. . .
Incor.1e fror.1 the aforer.1entioned activities is supplemented by subsis-
tence hunting and gathering, and to sone extent, assistance payments. In
addition to fish, residents of the area hunt \'1alrus, seal, geese, swains,
cranes, ducks, loons, and ptarnigan. In the fall, various types of
berries such as blueberries, cranberries, and salmonberries are har-
vested.
Table, 2.2'indicates the overall enployment,distrihution for Scam9n
lJay.
Gi 1 1 netti n9
BU1
CETA
Table 2.2
SCAt1"ON BAY 1979 EnpLOYt1E~4T BY INDUSTRY
Pa rt-Ti ne Year-Ro'and
l'
4
.'
SC AMMON BAY HIGH SCHOOL
SCAMMON BAY FISHING FLEET
Table 2.2 ConI t
SCA~'10N BAY 1979 EHPlO~1ENT BY INDUSTRY
Airport
BIA School
Retail
Parent-Child Program
Handkrafts
TOTAL
Part-Tirne
*
40
Year-Round
12/ 9-
8
2
31
Source: Alaska Department of Community and Regional Affairs
1/ Based on number of gillnet permits only. Actual participation is
greater.
~/ The new high school has added additional employment beginning in 1980.
*Number Unknown
2.2 NATURAL SETTING
2.2.1 Cl imate
The area has a maritime influence as indicated by its relatively
. moderate temperatures and precipitation. The Askinuk tfountains influence
the climate at SCaml':lon Bay, such that the various pressure systerns
approaching from the .ocean or the Yukon-Kuskokwim Delta have a direct
effect on the village.
The nearest climatological stati on is located at Cape Romanzof Ai r
Force Station approxirnately 15 air miles away. Although Cape Romanzof is
at approximately the 435-foot elevation and has a south\'iest exposure, it
represents the only nearby site for approximation of ,~ather at Scammon
Bay. Cape Ronanzof data, obtained from National Oceanic and Atmospheric
Administration (tJOAA) records for the period 1953-1978, indicate that
avera~e tenperature ranges during summer and winter are 34° F to 49° F
and 9 F to 31 0 ,F respectively, with recorded extremes of _26° F and 79°
F. The average monthly preci pi tati on ranges bebieen 0.98 and 5.00 inches
. \'1ith an annual average of 25.45 inches. The maximum monthly precipita-
tion for the period of record is 10.50 inches with the maximum 24-hour
precipitation being 2.77 inches. Table 2.3 and 2.4 provide a monthly
breakdo\'ln of precipitation, tetlperature, snO\'I, and wind.
2.2.2 Regi onal .Geology
Scamon'Bay is situated on the northern foot of the Aski nuk Hountai ns
in a region alrnost entirely cornposed of the flat, 10\'I-1ying deltas of the
Yukon anQ Kuskokwim Rivers, with an occasional rock hill rising several
6
II ,,'
TABLE 2.3
CAPE ROMANZOF
CLIMATOLOGICAL DATA 1/
PREClPITATION:~ JAN FEB r:1AR AP,R r-1Gl Y .. JUN JUL AUG SEP OCT NOV DEC ANNUAL
AVERAGE 1. 11 0.98 1.25 .97 1.28 2.13 2.95 5.00 4.62 2.39 1.56 1. 21 25.45
MAX MONTH 4.17 4.25 6.83 3.44 3.72 4.31 6.45 8.78 10.50 6.09 5.46 4.14 10.50
MAX 24 HOUR 0.99 1. 15 1.20 0.90 0.74 1.88 1.95 2.77 2.09 1.34 1.97 1.30 2.77
TEMPERATURE:
AVERAGE 12.9 9.7 13.5 20.7 34.4 43.3 49.2 4Q.2 43.7 31. 1 22.6 12.8 28.6
MAXIMUM 49 48 46 60 63 72 79 73 63 60 43 48 79
MINIMUM -23 -2f1 -26 -12 3 25 31 33 23 4 -7 -23 -26
SNOW PACK: 3/
AVERAGE 7.8 11.8 15.3 18.6 12.9 1.4 0.0 0.0 0.0 O. 1 2.9 5.9
STANDARD
DEVIATION 6.8 9.7 14. 1 20.6 8.3 3.3 0.0 0.0 0.0 0.64 3.2 5.7
STATION INFORMATION: LATITUDE -61 0 46 1 LONGITUDE -166 0 03' ELEVATION -434'
11 From Climatological -Data 1953 through 1978
Y Rainfall in inches
1/. Snow pack (including snow and sleet) on the ground" in inches, on the first of each month.
TABLE 2.4
CAPE ROMANZOF WIND DATA
(Knots)
SUBJECT JAN FEB MAR APR MAY .. lUN JUL AUG SEP OCT NOV DEC ANNUAL
. Preva i1 i ng
Wind, Mean
Ve locity 19.2 20.2 17.0 16.9 13.8 11.8 9.6 11.8 11.8 14.3 16.8 17.8 15.6
Direction NE NE NE . NE NE NE SSW SSW NE NE NE NE NE
% Time 16.9 21.4 17.1 15.2 18.0 12.6 14.7 13.0 16.6 19.7 18.6 21.3 16.2
~
. '
hundred to a couple of thousand feet above the delta p'1ain~ Ground~'
moraines in the cirques and valleys indicate extensive glaciation, proba-,
bly of Wisconsin Age,. , ,Pennafrost ·occurs'!spor.ad1'cal1,Y thrOughout the'
region, butrnay, not be 'evident:;in .rockifonnatioris,iwherethe Moisture, ,;"~~,,,
content ts,,~~pw. ., i"'... " ' ,.
.:~;. .'" f ,
2.2.3 i;.,Biology,
The, rnpst"i~portant:, ",i 1 dl,j fe resource of the Yukon-Kuskokwim Delta in
the v;cf,nity of Scamon Bay are the various species of birds that ,use the
coastal lowlands. Some of the highest density goose breeding areas in
the \'Iorld are found on the outer fri nges of the Yukon-Kuskokwim Del t~.
Thenajority of .the ,Yukon~Kuskokwim Delta is classified as wet. ;,'
tundra, "/hich primarily sUPP.orts low stands of sedge and cottongrass with
a fe\., woody plants •. With the lack of cover and. absence of year-round "
food sources, the western·-Yukon-Kuskokwim .Delta does not support large'
terrestrial mamals. , Only on rare occassionshavebig gamt animals been
observed near the proj.ect vicinity.
Five species ofPaci.fic:salrnon are i ndt"genous to the SCalllllon BaY :'
vicinity. alt,hOugh no salmon, ,enter the f~sm.,ater streams near 'the:' .
project 'area •. The bul kof ,the salmon found in the mari·ne \'Iaters off
Scammon Bay, are headed for the Yukon River drainage. '
2. 2.4 Anthropolo'gy~nd Archeology
" Accordi n9 :to the" StatE! ~i storic Preservat~on Office. no known sites:
are 'elfgiblefor inClusion in the National Register of HiStoric Places in
the Scamon Day area'.' .
:' " ,,'
2.~, ,ELECTRICITY USE '.
'2. 3.1 ' Histori c Use . ~ : , , , 'I
. ". Prior to joi ni ng the' Ala$ka Village Electrical CooperativE!' (AVEc) in
1974. Scammon Bay IS 1 iC1ited electrical needs were met with a few
individual generators ,and a small wi ndC111 1 that ,supplied potier for,two
homes. Since AVEC electrification, energy demand ·has gro\'In, .
substanti ally. . Tabh ,2.5 sho,'IS peak demand in kW and annual energy
generation for the years 1975 to 1980. Accurate records were not kept
during the early years resulting in missing data.
Table-2~~5
, .' . ' , '
, -.
SCAMMON BAY:' (AVEC ANNUAL PEAK',AND E.NERGY GENERATION) "
Year Peak kW Energy MWH
, ' '.' :", . .
1975 * .l59.2 '-. i'
1976 * 185.0
1977 * 203.5
1978 54 214.5
1979 78 269.3
1980 78 310.0
* 'Unknown
9
2.3.2 Non AVEC Generation ;t,
In add'itio~, to AVEC generation. the localBIA 'elementary school and
the ne\/lyco"$tr~ctedh1gh school maintaIn three 'standby ,generators'
totaling 1'60 kW. Under no nna 1 conditions. both schools would purchase .
pO\1er from AVEC. However. with the additional load of the ne," high '
school, uhich opened in Septenber 1980. the standby generators were used
almost daily to meet the increased demand. Recent IJpgrading of the'
existing AVEC generators from 50 and 75 kW to 75 and 110 kW has rectified
the situation. '
2~ 3.3 Usets .
In addition to the BIA school (three classrooms) and new "high school
(6,500~sq. ft.), the,comMunity has a variety of public and resi~ential
structures\lhl-ch conprise the electricity denand of Scamon Bay. Public
bul1dings'-include the community center. the traditional council building,
arnory;"',c·1inic. post office. Luther Aguchat Memorial Building. and two '
churches. t, Four stores,' several warehouses. a movie' theater. and the AVEC
building eire also located in the city. There are approximately 45 ,single
family dwellings in Seamon Bay; most are of wood-frame construction. ,Of
these. l!\ \1ere-'built in 1970 by the Alaska State Housi ng Authority. ' In
all ~ al)out'60, 'st""ctures' are served by AVEC. Of the 269~ 300 kWh gener-
ated' by AVEC in 1979, 107.500 kt"h ",ere for residential consumption and
94,800'kWh,:rentto government and school use. with the remaining used by,
the ut1.1ity or 10stdiJe to ~istributfon systeM inefficiency.' End 'use
data from 1975-1979 for Scannon Bay is shown: belotl: '
::' . j:.' Table 2. fi.
. ~,
END USE ELECTRICAL ENERGY
1975-1 979 AVERAGE
Village
Seamon B~
Residential
35~ :
Cornrnerical '
*Includes sChools and other public facilities. '
..; Northern Technical Services 1980 '
2.3.4 Total Energy Use,
Scamnon Ray is,cijrrently dependent upon fuel oil for space and water
heating and electrical generation. Propane is used in the village
primari ly for cooki ng. Gasoli ne is used for sno\'ft':lObl1es andfi shi ng
'boats. There is limited ,use of drift\«)od and the local willow brush for
horne heating. ' Table 2. 7descrii\es the end use of all energy fo""s
uti1f zed in' Seamon Bay duri ng 1979. The amount of fuel 011 used for
hone heating, ,divided by the nuMber of households, indicates a per capita
consumption of 680 gallons annually. This figure is 10\1 relative to
comparable villages. '
" , , " ,',
10
'-
., •.
Table 2.7
ENERGY INPUT AND END USE FOR SCAMMON BAY
Numbers in parentheses () are (10 6 Btu)
ENERGY
FORM DIESEL/ GASOLINE/
END #1 OIL AVGAS PROPANE ELECTRICITY
USE GiJllons Gallons Pounds Kilowatt Hours
Conversion to Elec-31,000 1 . 67,100 2
tricity (4185.0) (229.0)
,
Rf!sidential and 34,700 10,000 3 .107,500 4
small commerical . (4684.5) (216.7) (366.7)
space and water
heating
(nontransportation)
Municipal and other 6,000 15,400 4
DubHc (810.0) '(52.6)
(nontransportation)
Mil itary 2,300 900 4
(nontransportation) (310.5) (3~ 1)
Transportation 200 28,000
(27.0) (3500.0)
BIA Schoo) 29,000 78,500 4
(nontr~nsportation) (3915.0) (267~9)
NOTES:
1 Gross generation from 31,000 gallons fuel oil was 269,300 kWh for a conversion efficiency of 22.0
percent.
:'\r
"2" Power Consumed'by-the' utili'ty for station'service{lights, flJel~ pumping, etc.-) and~s·ystem di-str,ibution
losses.
3 Propane is used soley for cooking.
4 Net utility electrical sales in 1979 were 269,300 kWh.
Source: Northern Technical Services
, ,
I
I
l:
2.3.5 Ra~e Structures
nefore the Pmter Production Cost Assistance Prograrn (PPCA Program)
\'lent into effect in November 1980, bills "/ere claiming an increasing
proport ion :.of t,he vi 11 age I s cash economy. That proportion stood at
approximately 10 percent of annual cash income 1 n 1979. The po,.,er
Production' Cost Assistance Program dropped the effective kWh cost of
electricity frprn 40.8¢ to 26.6¢ for late 1980 and early 1981.
"
On 4 August 1981 t the Pm1er Production Cost Assi stance Program was
repealed by the Alaska Legislature and replaced with the Pm'ler Cost
Assistance Prograrn (PCA Program). This 'ne\., program, effective January
1982, \'Iill subsidize 95 percent of electrical energy costs (except return
on equi ty) greater than 12¢ and 1 ess than 45¢ kWh. Thi s \,/ill drop the
consurner cost of electricity, at Scammon Bay to approximately 21.3¢/kWh
from the aCl.lta1 utility cost .of 48.3¢/kWh. The utility rates si nce AVEC
pO\'Ier \'Iasintroduced in Sc~rmnon Bay. are presented in Table 2.8. The
single rate schedulesho\mis applied to all 48 AVEC villages and is I
designed to recoup the costs of the entire system. Costs attribut~ble to
any sing1~ village are difficult to ascertain. ,1
Year
1975
1976
1977
,1978
1979
1980 '
'1981
. "
. , .,T~b1e 2.8
AVEC RESIDENTJAL RATE 1975-1981 . (75 kWh)
. " ..
21.9
22.8
29.0
34.2
36.7 . " ,
40'. A
48.,3
. .
Consumer Cost (¢per kWh)
21.9'
22.9'
29.0 '
34.2
36.7. . . . .
26~6 (PPCA Program)
21.3 (PCA Progr~
after 1 Jan 82)
For electrical generation, :fue1 prices have been the principal sou,rce
of rising costs. The average cost of diesel fuel delivered to AVEC
villages since 1973 is shot'" be1m.,:
. Table 2.9
. AVEI1AGE COST OF OELIVE,RED FUEL TO ALL AVEC VILLAGES 1973-81
Year'
1973·
1974.
12
Cost ($/gal).
0.35
0.52
..
Table 2.9 Con't ..
. AVERAG.E COST OFDELIVER~D FlIELTO ,ALL AV~C VILL~GES 1973-81 . _: ,_
V,ear -. -" . :,' ,~"::Cost ($/ga1) ,
'.(, 1975 0.58
1976 0.65
1977 0.72
1978 "0.78
1979 0.97
1980 1.33
'19m 1.62
Based on data provided by NORTEC, AVEC's Scammon B~ generators
produced an average of, 8.7 kWh/gal from January 1979 to Septer:1ber 1980.
Assur.1i n9 the output rate rer:1ai ned the same for 1981, it \'IOu1 d take 18.6({
\'IOrth o~ diesel fuel to produce 1 kWh of electrical energy.
13
PROBLEr1S, NEEDS, AND STUDY OB ... 1ECTIVES
, Based upon ScaM~on Bay IS' i "iti'al study request and subsequent i nfoma-
tion gathered during four site visits, it became apparent that a plan
needed to' be formulated that would reduce the cost of power to the local
residents~ With theestabl i shrnent of the PO\'ler Cost Assistance Program
by the State of Alaska, th~ basic objective of reducing cost to the ,
conSUMer was met, at 1 east for the short term. However, thi s program is
only a subsidy. doing no1;.hing to reduce the real cost of power
production. Therefore, the study objectives were reestablished as
foll QWs: '
1. fteduce the real co~t of energy generation.
2. t1~'ntain't.he exiSting ~rivironmental quality in and a'r9und'the~
village to the maximUM extent' possible.
' .. '.
In addition to the above study objectives, the national objectives of
National ~conoMic Developnent-(NED:} and Environmental Quality (EO) must
be considered. NED is obtained by, increasing the level of output or"
economic efficiency of the nation and the EO objective is obtained by
preservi ng, rnai ntai ni ng, or enhanci ng the cultural and natural resources
of the study area.
, . ~
The following sections provide a sumary of the generating ,
capabi 1 ities of Scammon Bay and an':estinati on of the future energy ne~ds
that must be,met by any alternative.
, ,
3~ 1 POWER SU PPL Y AND FUTURE DEf1AND ,
3.1.1 Generating Facilit~~$'
. '. " (" .
The generating capabili,ties of Alaska Village Electrical
Cooperathe'siScamonBay~:ienerators are shown below. Besides those
shown, a 105 kW generator is scheduled for installation during early
1982. ,
1 -75kW. 1,800 rpn, KATO n971), 120/240, HI,' 75,kW
,1 -110 kW, 1,800 rpm, KATO'(1971}, 120/240, H4, 110 kW
185 kw
In addition to AVEC's generators, the standby generating capacity of
-the new high school and IlIA school'tota1s 160 kW. The high school
generator is new \"hi1e the RIA units are bet\oteen 10 and 15 years old.
These are shown below: " '
High School 1 -100 kW, Ne''Iage -Stanford, 120/240,
BIA School 1 -' 35 kW, Kohler 120/240,
1 -25 kW, Kohler 120/240,
14
100
35
25
TOO'kW
..
3.1.2 GEme,r;aticln and Transmission Effici.ency ,: .. "., '"
.. t'; j -:u f . . .
In 1979,'rAVEC's,gross,generation from 31,000 gallons of fuel oil was
269,300 kWh for a conversion efficiency of 22.3 percent. Station service'
and rlistribution losses ~mnunted to 67,100 kWh(o~ approximately 25 per-
cent of :the gross powergenera'ted. AVEC's records 'indicate a total .'
syster:1 dlstribution loss of 47,600 kWh or lB percent. This is cbnsidered
typical of a single phase distribution system.
3.1. 3 Futll~e Activity An~Ener9Y Needs
It is diffi~u1t to accurate.1y predict t'he future electricity demand
in rural villages, because it is difficult to predict the economicgro\'rth
of an individual community. Economic, growth depends ,on the development
opportunities exercised under the Alaska N'at.ive C1air:1s Sett1enent Act,
the general economic development of the State and region, and the :
avai1ahility of electricity to the" cOr.1r.1unity. In addition. each village
is a small isolated. unit. A change in the habits of 'a fe,., hou'seho1ds or
the 'local school can' have: a' dramatic effect on the total level' or '.
composition of e1ectricity'demand ina cOr.Jm.Unity. r10re 1mportant1y,tthe
level of denand in any' hush village largely ~epends on, goverment
decisions made outside th~contro1 of the community. The electric, ,needs
of AVEC villages are 'Mainly detemined by the demand generated by the'
following installations:
a. State .Schoo1 s'
b. BIA Schools','
c. Public Heal th' Services
d. Housing Authorities
e. Fede,ra1Aviat.10nAdmfnistration
f. 'Satellite Comr.uJnications
Recer:-t construction acti yities in Scamnon Bay i nc11;d~' th~previously
mentioned high school' and a \'Iater, supply distribution system installed by
the PiJtllic Health Service in the mid 1970's. ,Construction of 24 new,'
single family homesis'scheduled for cOl7lpletion by June of 1982. These
ne\'1 hOllsing structures are expected to vary from 860 to 1,100 square'
feet. Theconrnunity ha~ a1 so been seeki ng fi nanci ng for a gymnasium.
3.10'4 Ll?n9 Tern Outlook
,.
Look; ng, heyond the 1980' s, Scammon Bay presents potential for both
growth ar;td decline., ~robab1y the, largest"single contributingfactor(to
the futUre outlook of ScamonBay and other isolated A1~skan Vil1ag,~s is
Alaskas L oil wealth. HO\'I the State ultimately spends, its oil revenues
\'Ii 11 9,reatly '; nf1 uence . the future grO\,rth ofrenote vi 11 ages •.
Any expansion in the Scar:1m<;m Bay economY besides government positions
\'Iill probahly be in the fi'shing industry.,Thi,s influeoce has already
15
I
r
been felt by the previously mentioned 1 nvestment in herri ng fishi ng boats
by the Alaska neneuable Resources Corporation. However, expansion in the
foreseeable future \'Ii 11 rnost 11 kely conti nue on a rel atively small
scale.
3.1.5 Load, :~orecasts
Any forecast of future energy denand for Scammon Ray is, by
necessi ty, very specLil ati vee Beyond the existi ng demand and the future
deMand of the new housing units, energy forecasts are extrernely uncer-
tai n~ Once construction of the netl homes is complete, the demand may
stabilize."at least until additional unforeseen capital improvements take
pl ace.'; 'Ho\'1ever, with the passage of the PCA Program, which will drop
rates to less than 25d/kWh, the 11kelihood of the demand stablizing
sUbstantially appears to be remote. '
The nost recent energy demand forecast was developed by NORTEC for
the Alaska Po~~r Authority prior to the PCA Program. Their forecast
inCluded the effects of theneu high school in 1900 and the 1981-1982
, addi ti on of 24 homes. Above that, a conservati ve grm'lth rate of
approxinatelyO.9 percent \'1as used. Thi s is substantially less than the
actual increase over the past five years, but they assumed that the
relatively rapid electrification of individual homes that has taken place
since joining 'AVEC \'IOuld stab11ze. Future increases due to added
appliances \'lere assuned to be offset by conservation and nOre efficient
appliances. ' This energy forecast (Figure 3.1) is now considered to be
,the 10\'/'growth scenario ~up. to the decreased cost to the consumer
pro.'i1ded through the, PCAprogram. ' ,
. 'AlsoshO\l" on Figure 3.1 are growth projections of 14.3percent, 11
percent and 4.5 percent.' The 14.3 percent fi gure rep resents an extrapo-
1 ation of the electrical gro\·lth rate between 1975 and 1900 at Scaminon
Bay. 'The 11 percent fi gun! corresponds to the 1970 to 1980 growth rate
at Rethel,)\laska. Neither of these are considered to be indiCative of .
future gro~lthat Scar.lr.lon Bay., The first figure represents avery short '
period of record during the tine of initial electrification ~t Scamon
Bay, the latter, which has a longer period 'Of record, represents a larger
c0r.1ni:ln:fty \Iith a,broader econonic base.' , ,
The R.W. rtetherforci Division of International Engineering Company,
Inc., conpleted a study of energy requirenents and alternatives for 13
villages in \'/est and ,north\'#est Alaska. Based on their analyses, an
electrical gro\1th rate of 4.5 percent was found to be reasonahle for
these villages, many of \'/hich are sirnilar in size and ecotioCl)' to Scall'r:1on
Bay. Therefore, a grO\,lth ,rate of 4.5 percent \.,as adopted,' for this study
begi nni ng in 1982. "Thi srepresents the base case forecononiic evaluation
of h~'dropo\'lerat Scamon Ray.
Figure 3.2 ShoNsthe estiMated'monthly distribution of energy gener-
a~i on for 1982 and 1990.' ,The percentages \'#ere based on 1979 usage
p~tterns'. ' ,The, conbi nati on of i nfomati on presented in these t\'IO figures
\,/asused'to, provide the basi,S for evaluating alternative energy plans.
16
------_ .. __ ._. __ .. _--------_ .. _--_ .. ----
850
800
750
700
650' ,
(f'J 600 a:
::l '0 550
:r:
I 500
l-.,1-.= 450
I Iii( 400
(!)
L&.I 2 350
300
250
200
" I
I
I
I
HISTORICAL I PROJECTED
. GENERATION ·GENERATION
PROJECTION BASED
ON HISTORICAL ..
INCREASES 04.30/0)
I .
.. --' I'"
I
I
I
I
I
I
,.;r. ,.
PROJECTION BASED ON
~ BETHEL HISTORICAL
INCREASES' (110/0) . . :.::
RW. RETHERFORD'~"
ASSOCIATES
.AIIi--PROJECTION
NORTEC PROJ ECTION
ADOPTED FOR THIS
. STUDY (4.~~/o)
PRIOR TO PCA PROGRAM (0.90/0)
FOR PLANNED HUD HOUSING
FOR NEW HIGH SCHOOL
. SCAMMON BAY, ALASKA
HISTORICAL 8 PROd ECTED
ENERGY GENERATION
75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95
YEAR FIGURE 3.1
------------------------------------------
CJ) a::
::> o
70
I 30
I
I-~ ~ <t 20
(!)
W
~
JAN FEB MAR APR MAY ... JUN JUl AUG SEP OCT NOV DEC
-MONTH
EZJ 1~82
~19~
SCAMMON BAY, ALASKA
ESTIMATED MCNrHLY
ENERGY DEMAND
)to ...-..
FIGURE 3.2
FORr1ULATION AND EVALUATION 'OF ALTERNATIVES
,': ,/.
4.1 ALTERNATIVES
Under section 1.4, STUO;.IES OF OTHERS. the\'lork done Tor the Alaska
PO\'ler Authority by NORTEC \';as sur.tl1arized. "NORTEC's conclusion ,~as that
energy conservation (insulation and "teatherization), continued use of
oil, waste heat recovery, hydropO\~er and possibly wind generation \'1ere
the hestalternatives for Scamon Bay. These were the only five "
a1 ternatives that met both requi rements of bei ng technically feasi hle and
constructab1e in the study area. Other alternatives such as geothermal
or tidal [lO\'1er are not technically feasible at Scamon Bay due to natural
constraints. ' ~
4.1.1 Diesel
This alternative is effectively the existing condition. Under this
scenario diesel generation would continue to be used to meet'al1 .
electrical requirer.lents at Scarnon Bay. tHth the addition of the new 105
kW generator, sufficient capacity exists to meet village demands for the '
foreseeable future.
Impact Assessment
,The prinary impact associated \'1ith this alternative is economic.
Although the peA prograr.l \'1illlo\'1er diesel prices to their 1975 priCe
1 eve 1 s, the cost of di ese 1 fuel ",i 11 eventually ri se agai n as shortages
occur and (femand exceeds supply. By continuing to use diesel, the '
village is leaving itself exposed to possible shortages in the future if
suppli es, are interrupted due to physical or economic constrai nts.
Evaluation
Since diesel has heen established as the base case bY\'/hich other
alternatives are to be evaluated, it is necessary to determine the actual
generation cost atScar:non Ray' for cOr.lparison. The Alaska Village
Electrical Cooperative 1981 cost is 48.3(t/kWh. This system wide cost
includes not only fuel and operation and r.laintenance, but also taxes,
insurance, interest. depreciation, and administration.
Of this kHh cost, not all can be considered as a savings or benefit
if an alt.ernative is inp1emented. Only fuel savings,and operation and
maintenance,costs (O&r1) can be clained as benefits unless an alternative
can be inp1er.lented that is reliable enough to prevent the need for
aquiring additional diesel generators to neet peak loads; then', it can be
credited for the firm capacity it provides. This is called the capacity
benefit.
The tHO parts of the energy benefit, fuel and operation and
rna; ntenance, Nere determi ned from information prov; ded by AVEC. AVEC's
1981 die,sel cost at Scar.lnon Bay of $1.62/gallon, coupled with their
g~nerating efficiency of 9.2 kWh/gallon, provides a fuel cost of
19
17. 61¢/kWh,. This, coupled "lith AVEC's operation and maintenance cost of
6.2lt/kWh renders a cost of diesel generation (or benefit when compared
to an alternative) of 23.84<f/kWh for 1981. When conparing this cost to
another alternative, consideration must be given to how the fuel cost
pl)rtion nay change in the future. \~ith total fuel price increases at
Scammon Bay of 212 precent, from 1974 to 1981, it is easy to see that
energy costs have far outstripped inflationary increases over,the same'
time period. To account for this escalation relative to the general
inflation rate, a fuel cost escalation rate must be established for
project evaluation.
Various fuel cost escalation rates over varying periods of tine have
been usedi n the past to estimate future fuel costs. r~ost of those
proposed in the past have fallen short of what the actual escalation rate
turned out to be. Accordi,ng to the Bureau of Labor statistic for
Anchorage (none are available for Scammon Bay), the inflationary increase
from 1974 to 1980 was 67 percent compared to fuel cost increases of 156
percent.' Based on this data the annual fuel cost escalation rate (above
inflation) was over 11 percent. Although there is little chance that
this high of a rate \'Iill continue, it does demonstrate the difficulty of
estinatingfue1 cost escalation. '
For the purpose of thi s study, the fuel cost esca1 ation rate
developed by the U.S. Department of Energy (DOE) for the 1980 Annual
Report to Congress has been adopted. The proposed escalation rate is
shown below:
YEAR
1980-1984
1985-1989
1990-201 0
ANNUAL
ESCALATION RATE
3.1 percent
2.2 percent
4.0 percent
These incr.eases would 'result in the following fuel price'S at Scarmnon
Bay:"
4.1.2 Conservation
Oescri pti on
1985
1990
1995
2000
19.7¢/kWh
22.4<f/kWh
27.2¢/kWh
33.1¢/kWh
, "
This alternative requires the imp1enentation of various methods that
would reduce or restrict the use of energy. Adding additional insulation,
installing stom \'1indows, \'Ieather stripping, upgrading the distribution
system etc., are the primary methods of implementing this alternative.
Some form of load nanagement may also be possible.
20
•
I~pact assess~ent
This alternative has virtually no adverse environnental i~pact \'Ihile
having very. positive economic and social' i~pacts·.·, ·If imp1e~ented,
significant savings in heating costs could be·rea1ized by the villages.
The ir.lpact :on electrical use would be slight however, because very
little, if any, electricity is used for heating and the overall Village
energy use is minir.lal \'1hen compared to larger communities. The cost of
electricity is so high that minir.lizing its use has become a way of life.
Conversion of the distribution system from single phase to three phase
could significantly reduce the 18 percent distribution loss. HOHever,
according to AVEC, the re1atively'small increase in efficiency, coupled
with the sna11 size of systen, does not warrant the expense of converting
the system.
Evaluation
Energy conservati on is probably the simplest ~ethod to reduce overall
ene~gyconsumption in the village. Although its imple~entation \.,ould
have ninimal effect on electrical consunption, the benefits fror.l reduced
heating costs would be great. Execution of this alternative should be
pursued at the earliest possible time.
Implementation nesponsibi1ity
'The nasic responsibility for irnp1er.lenting this alternative lies '\'/ith
the local residents. To aid in this responsiMlity and to lessen the.
burden, various State and Federal prograr.ls are available. The State
offers' energy auditing services, conservation grants and 1m-I interest
loans while the federal' government offers income tax credits. These
opportunities should be pursued to the maximum extent possible by t~e
conmuni ty.
4. 1.3 Haste lieat P.ecovery
Descripti on .
. TltO foms of potenti a1 energy recovery from exi sti ng diesel
generators are possible. , The first is direct waste heat recovery for
heating purposes. This is accor.lp1ished \'lith the use of heat exchangers
\"hich transfer waste heat from the "later jacket and exhaust of the diesel
generators to another fluid that can be used for hot water or building
heating. Direct waste heat recovery requires that the generators be
close to the building or Hater supply being' heated, othen/ise heat is
lost to the at~osphere. The second fOnT! is by use of the l1anki ne Cyc1 e.
This systen vaporizes a fluid such as freon ,"ith the waste heat from the
diesels. The freon, ''1hich is under high pressure, is then used to ~rive
a turbi ne "hi ch ,·Ii 11 produce shaft horsepm'ler to turn the generator' for
additional electrical power.
21
Inpact Assessnent
The prinary negative inpact associated \'lith waste heat recovery at
Scammon Bay would be ,the relocation of the AVEC diesel generators because
their present location is too far from any major building or water
supply. Although relocation is possible, it is doubtful that it could be
econonic,ally justified even at current fuel costs. .
Evaluation
As nentioned in the previous section, the present location of AVEC's
power plant in Scamon Bay is not suitable for direct waste heat
recovery. The high school has a 100 kW standby generator that could be
used for \'/aste heat recovery for the school, but A1 aska State 1 a\'I
requires that all schools purchase their pm.,er fron existing utilities if
present.
The Ranki ne eyc1 e energy recovery systens are no\'l in the deve10pnent
stage. When they do become commercially available it will probably only
be for uni ts above 1000 kH •.
Implementation
Inp1enentation ofa Haste heat recovery systen ''1ou1d be the·
responsibility of the vilhge of Scamon Bay in conjunction ,·lith AVEC
''lith possible aid fron the State of Alaska •.
4.1.4 Wind Generation
J)escription .
The possibility of developing a feasible ''lind system at Scal!1r1on Bay
appears relatively good. Although no \'/ind data has ever been gathered at
Scannon Ray, it is known that high ",inds of long duration are cor.nnon
during thew.iriter months. ,If a ''lind systen \'Iere developed it would
probably consist of anun~~r of units in the 10 kH range.
Rased upon Cape Romanzof data, mean yearly wi nd ve10citles average
15.6 nph. The \'Ii nd is predoni nant1y from the northeast duri ng Hi nter
months \·,hen velocities· are the greatest. Although Cape Romanzof data
should not be used directly for Scamnon Ray due to its higher elevation
(434 feet), the mountains in beb/een it and Scammon Bay and its southwest
orientation, it represents the only data source for the area. The
general trends in \'Ii tid speed and duration \'1ou1 d t.end to apply to ScaJi1J;1on
!Jay.
According to various sources, an economical "/ind installation is
possi b1 e '''hen the mean wi nd vel oci ty ranges between about 12 and 16 mph
depending on the size and type of unit, and the degree of sophistica-
tion. Simple systems consisting of direct current generators can operate
22
':'"
economic~l\y' a1!'lower wi nd sp'eeds if the user i swilli ng to use the
el ectrjc:Uy strictly for DC lighti ng and resi stance space or hot water
heat; ng.'; At Scammon Bay, ,where ,a ,relatively complex electrical syster.J
already exists, it Would be 'necessary to install a wind system that ''Iould
be compatible with the existing diesel generators.
l , '
This could be done on a smaller scale with the use of a .
sychronou~-;nverter which would depend on the existing utility system to
~ontrgl, :tJ)e(.v()lt~~~ •. ~Q!le,problem withthis system is that the total wind
pgFl@r~Rl'J~ ~~paga'yj't9a~ ~01,l1~ b,~,,~~~~ wquld be limited to a small
nn~·l f,A(J' {.l(f H"en u:fo"l ''''''y.~~ It,nta] .,nutnut ... ,,}jf;,t.oo '1 arge of a,':propor,'I! ~. )"" 1:'.!Vi't ~, l'~ lr"o .• ~f~\"t!-&.. '-.::'1 t-t'1"., ... ~ '", .• ~\ n·.' ~,' i)t ,;j\li*.h~ ~ "J~',; ." 'J: i~~,,~ .toJ,.' ....... "'fll}l \",,.\~~ •.
lttQ'i :510~!.i~hanoaQg"~ea5cP'~9~'ilt'1)1~a$:)lPtgg~ced by the ''Ii nd syster.J, the
utility could no ,longer control the voltage.
1 " ' To operate wind generation that would be fully compatible with the
existing diesel generation system and that could operate as the prime
power sou'rcefor the utility, may double or even triple the cost of the
. , ' cheaper uni ts. No systems, of th,i s type are currently functi oni ng in
Alaskaa;nd their ability to function in the Scamon Bay, climate is
unkno\·In.' ' ,
Eva 1 uati!on
, " I
To prove feasible, a wfnd generation system of the type needed for
tota 1 compati bi li ty wl th the exi sti ng generati on system woul d probably
needr.Jean monthly wlnd velocities in excess of 15 mph. Using Cape
Romanzof data, mean velocities in excess of 15 mph occur frOm October
through 'and April. ' " '
Althoughdi esel generation cannot he totally displaced by wind f:"
generatiQn becallseof the need for standby generation durl ng peri,ods' of
calr.l, l,t appears that"it could displace a significant amount of diesel
fuel, particularly in the ,winter months. However, until wind data is
acquired at SCanr:lon Ray, ,it ,is impossible ,to accurately assess the actual
pote~tial oratter.Jpt to optimize a wind syster.J design.' " ,
Implementation 'Responsibility,
f,
, j
Implementation of this alternative \~uld be the responsibility of
ScarnmonBay with possible aid ,from the State of Alaska or the De~ar;rnent
of Energy." " ' ' . ." , ,
4. 1 ~ 5~ydroel~ctri c
Description
This alternative consists of a rockfilled gabion darn with a top
elevation of 600 feet, 3,500 feet of 12-inc~ steel penstock, and~a
10xll-foot po\'If!rhouse containing'~ne 100 kW impluse turbine. Based on
avail able ·streamflow data, the estimated annual energy output from the
systernts approximately 430,000 kWh, of which 239,000 kWh (55 percent) is
23
estimated ~q,!.,be usable in 1983, the first year of operation. The other
45 percent'i s produced dliri ng the sumer and "iou1 d exceed' the cOmr.1uni ty'l s
current der:Jand. Diesel generation ,"/ou1d be required as 'a supplement when
;nadequ~te Jlo\',s exist to,r:Jeet a'llder:Jands, approxir:Jately six r:Jonths per
year. A detailed discussion ofth~ plant sizing is included under the
section "Technical J\nalysis. II
Impact ,Assessment
Adverse envi ronnental inpacts associated ''lith thi s project, are
relatively minor in nature. No fish uttHze",the small stream where the
project uould be located. r1inor, disruption of nesting and rearing shore
birds may occur during project construction. Special care would be
necessary during project construction to confine work to nonpermafrost
areas. ,Social impacts would be positive over the life of the project
because a capital intensivehydropO\'/er project would tend to hold down
electricity costs in the longrun, although initially it may be more
, expensive.
, Eval uation
A sunnary of the associated costs and benefits for the hydroelectric
system are'shown in Table 4.1. The analysis is based on October 1981:
price levels, a discount rate of 7-5/8 percent and a 50-year project '
life. The. b~nefits are based on ,the direct displacement of energy that
would have 'to to be,produc~d by, diesel 'fuel to neet estimated ,demands.
Figure 4.1.1 shm1s the relationship of available hydroelectric energy
versus estinated' demand. ' Figure 4.2 shO\'1s peak Monthly deMand ve'rsus
average monthly hydropower output. The mi nimal amount of ponda'ge
(approxir:Jat~,ly 1/10 acre-foot) ,shou1.d allo\'l peak demands to be met if the
average output is 1 ess thim the peak and the peak does riot exceed' a ' "
couple of hours. . , . '.,
The be'nefits for the hydroelectric system at Seamon Bay were
detemined 1 stric:tly by the displacement of fuel and the savings in
operation and r:Jaintenance on the diesel generator. No credit was given
for displacement of diesel capacity since the hydropower system would not
operate during the peak demand months.
The savi ngs in di esel . fuel \'las computed from a' 1 981 cost of
$1. 62/ga 11 on (1 7. 6¢ /kWh), that ,:,as escalated unt 11 201 O,according to
DOE I S estimate. Credit \',as al so gi ven to the project based on its
ability to ne~t the estir:Jated 4.5 percent yearly increase in demand.
Savings in Operation and r1aintenance was credited at the rate of
6.23¢/kHh.. Table 4.1 provides a sUlmlary of the estir:Jated benefits and
costs.
24
. I
. ..
, "
I I
, ..... ..... «
70
60
50
, 3:.30
,e:{
(!)
W '
~
20
10
SEP OCT NOV DEC
MONTH
I r=d HYDROPOWER OOTPUT
~ ENERGY DEMAND
SC A MMON BAY , ALASKA
ESTIMATED MONTHLY
ENERGY DEMAND AND
HYDROPOWER OUTPUT
(100 kW) FOR 1983
F IGURE 4.1
-120
~
~
'--
0 100
Z
~ 80 ~
~ :::c 6 0 ~
Z
0 ::e 40
~
<t
W 20 0-
[::J HYDROPOWER CAPACITY
~ PEAK DEMAND
JAN FEB MAR APR MAY JUN JUL AUG SEP OC T N\N [EC
MONTH SCAMMON BAY, ALA SKA
MO NTHLY PEAK DE MAND a
AVERAGE HYDROPOWER
CAPACITY FOR 1983
A L A SK A DIST., CORPS OF EN GIN EERS
PL AN NI NG a ~EPORTS BRANCH
PREPA RE D BY : MF e DATE:
..
Table 4.1
Project Costs And Benefits
First Cost
Interest and Amortization (7-5/8, 50-yr)
Operati on and '1ai ntenance
Total Annual Cost
Diesel Oisplacer:1ent Benefit
Fuel Cost Escalation Benefit
Operati on and t1ai ntenance Benefi t
Total Annual Benefit
Net Annual Benefit
Benefit-Cost Ratio
Inplenentation P-esponsibility
$1,130,000
88,400
20,000
$108,400
$ 62,900
40,100
22,303
$125, 300
$16,900
1. 16 to 1
Various options are possihle for the ir:1pler:1entation of this
alternative. Under all scenarios it is anticipated that the local
utility \'/Ould be responsible for the operation of the plant. The options
available are listed bel 0"':
1. Constructi on by the Corps of Engi neers \'Ii th Federal fundi ng.
2. Construction by the Corps of Engineers with State funding.
3. Construction by a private fim \1ith State or utility
funding.
27
N co
4.2 SUMMARY OF ALTERNATIVE PLANS
1. Pl an Oescri ion
2. act Assessment
A. Economic Impacts
Total Benp.fits/yr.
Total Cost/yr.
Benefit/Cost Ratio
Property Values
Tax Revenue
Regional Growth
Emp'loyment
Without Condition
Total diesel p.lec-
trical generation
None
N/A
No Change
N/A
No Change
No Change
Business Activity No Change
Displacement Homes, etc. N/A
Alternative A
Hydroelectric plus
diesel generation
$125,300
$108,400
1. 16
No Change
N/A
No Change
There would be a few
short term jobs during
construction.
Temporary increase due
to construction activity.
All construction would be
in areas devoid of housing.
Alternative B
Wind plus
diesel genera-
tion
Insufficient
information
exists to
assess the
economics of
af a system
that could
function with
the Scammon Bay
utility. No
similar system
currently
exists in
Alaska.
No Change
N/A
No Change
Same as Alter-
native A
Same as Alter-
native A
Same as Alter-
native A
N '\D
B. Environmental Impacts
Archeological
Water Qua 1 ity
Water Quant ity
Air Po 11 uti 0 n
Natural Resources
~-.-,----~, .. --------~-------'-y-~~----'-----"
4.2 SUMMARY OF ALTERNATIVE PLANS CON1T
Without Condition
No Impact
No Change
No Change
No Change
Continued consump-
tion of fossil fuel
for total electrical
generation need.
Alternative A
No archeological sites
have been identified
in project area.
Temporary increase
in tUr"bidity r:lurinq
construction.
Reduction at point of
village with~rawal~ but
operation should not
affect village water
supply.
An increase in particulates
would occur during con-
struction~ no long term
effects would occur.
Construction activities
would temporarily in-
crease the use of fossil
fuels. The project
would reduce fossil fuel
dependence.
Alternative B
Same as'Alter-
native A
No Change,
N/A
• Same as A lter~
native A
Same as A lter-
native.A
w o
Lands
Habitat
C. Social Impacts
Noise
Displacement of People
Esthetics
Community Growth
and Cot'lesion
-----.-~----------.------------------------
4.2 SUMMARY OF ALTERNATIVE PLANS CON'T
Without Condition
No Change
No Change
No Change
No Change
No Change
No Change
Alternative A
Construction to take
place within the imme-
diate vicinity of the
stream to minimize
permafrost damage.
Minor temporary dis-
turhanceof certain
birds during construc-
t ion. .
Slight incrp.ase during
construction followed
by a decrease once
project is on-line.
No Change
No adverse visual effects
in town, minor adverse
visual effects at site.
No Change
Alternative B
Core must be
taken to avoid
permafrost
damage during
construction.
Same as Alter-
native A
~ame as A lter-
native A except
wind generators
may cont i nue to
produce noise.
No Change
Defini te ad-
verse visual
effects at
town site.
No Change
3. Plan Evaluation
4.2 SUMMARY OF ALTERNATIVE PLANS CON'T
Without Condition
Unrler existing con-
ditions, Scammon Bay
residents will con-
tinue to use fossil
fllels for total
electrical genera-
t i on • Th i s wi 11
cause increasing
electrical costs
as well as a depen-
dence 0n imported
petroleum products.
Alternative A
Hydroelectric generation
along with diesel fired
generator's complement
one another. During
hydr'oelp.ctric genera-
tion fossil fuel depen-
dence would be reduced.
Hydroelectric generation
is seasonal depending
on -s treamfl ows.
Alternative B
Assuming
favorable wind
condit ions.
wind generation
is capable of
lessening
fossilflJll <dp.~
pendence parti-
cularly during
the winter -
months. Lack
< of wi nd data
make this -
a lternat i ve
questionable;
however. it'
appears to
warrant further
investigatl0n
and data
gathering.
l!,.3 NED ~PLAN
Federal "later resource development policy requires that the
alternative providing the greatest amount of net benefits be designated
the National Economic Development Plan (NED). For Scammon Bay, the NED
Plan is hydroelectric. It "/ould provide net benefits of $16,900 annually.
4.4 EQ PLAN
Federal \'later resource developMent pol icy al so requi res the·
designation of an Enviromental Quality Plan (EQ). This should be the
plan that makes a net positive contribution fo the environmental quali:ty
of the area. In the case of Scammon Bay, no plan has any significant
environmental impacts; hm'lever, neither does any plan make a net positive
contribution to the environment. Therefore, no EQ plan can be
designated. In this case it is necessary to establish an LED Plan (Least
Environmentally Damaging). Although the diesel system produces exhaust
and noise, it is already in existence and no additional construction
\'/ould be required, therefore it is designated as the LED Plan.
4.!i SELECTED PLAN
The Se.1ecteo Plan should be the plan that is the best over all scheme
to meet nati onal and 1 ocalobjecti ves. For Scar.m1on Ray, the hydro-
electric system is designated as the Selected Plan. This plan is capable
of produci'ng approximately 432,000 kWh of energy per year on the average,
of \1hich 239,000 kWh is estimated to be usable the first year of
operation.
32
..
CONCLlISIONS AND RECott1ENDATIONS
5.1 CONCLUSIONS
Based on the ana1ysis contained in this report, hydropouer provides
the best alternative for electrical generation at Scammon Bay. A
detailed analysis of this is included under Section T, TECUNICAL ANALYSIS.
\4ind'po\'/er appears to hold promise, particularly in the \'Iinter months
"/hen stronger \'Ii nds of longer durati on occur. Based upon the \'Ii nd data
froM Cape nOr.1anzof and an assumption that the general trends hold true
for Scaonon Bay, \'Ii nd coul d prove to comp 1 ernent the hydropower SysteM •
During the sumer months "'hen hydropower is at its peak, wind generation
potential is poor. [luring the \'Iinter, Nhen hydropm'ler potential is poor,
Hi nd potenti a1 is high. Ho\'Iever. before a r.tore accurate detenni nat; on of
exact potential can be nade, a continuous recording anemometer should be
installed. The State Division of Energy and Power Development may be
able to provide assistance to Scarnnon Bay through their anemometer loan
program.
Weatherizing through insulation, storm ''Iindous, and \tleather stripping
could provide significant savings to the community in the area of hone
heating. Any effect on electrical der.tand ,,,ould be sr.tall. This option
should be pursued to the maximum extent possible by the village.
Upgrading of the distribution system does not appear to be feasible
at this time. HO\'Iever, if Scammon Bay should sho\'i unexpected growth and
fuel costs continue to escalate at a rate sioilar to the past few years,
the incremental reduction in distribution losses nay \1arrant conversion
to a three phase syster.1.
5.2 TENTATIVE RECOIU1ENDATION
Ireconmend that the Scaonon Ray Hydroelectric Project be authorized for
constru'cti on \'Iith such r.1odificati ons that may be advi sabl e made at di scre-
ti on of the Chi ef of Engi neers. Des; gn and Construct; on rtanagement "lOu1 d
be the responsibility of the Corps of Engineers with an estir.tated first
cost of $1,130,000 to he provided by the State of Alask~ or other
nonfeder.a 1 sponsor. Upon paYr.1ent of post authori zati on costs, the
project would he turned over to the nonfederal sponsor for ownership and
subsequent operation and maintenance estimated at $20,000 annually.
33
SECTION T
TECHNICAL ANALYSIS
34
TECHNICAL ANALYSIS
T. 1 GENErlAL
The selected plan for hydropmter development at Scammqn Bay is a
run-of-the-river diversion project ''1hich has a capacity of 100 kW. The
project,consists of a 50-foot Hide rockfilled gabion dan with its crest
at 600 feet elevation, 3,500 feet of l2-inch buried steel penstock, 'and a
10xll-foot pOHerhouse "lith one 100 kW rated impluse turbine unit. ,I
This system would provide most of Scammon Bay's current energy needs
for approxinately six nonths of the year. In late fall it ,"ould be'
necessary to supplement it ,"ith diesel. For approximately four months of
the year it Hou1d be shut dO\-1n due to inadequate streamflo,".,
Thesysten could generate an average of approximately 432,000 kWh of
electricity annually at an estimated first cost of $1,130,000, \'Iith net
annual benefits of $16,900 and a BIC ratio of 1.16 to 1. A detailed
description of the design considerations and paraneters fol10\'1s.
T.2 HYOROLOGY
T.~.l nasin Oesc~iption
The three'-quarter-square-nile drai nage basi n vari es in el evati on fran
600 feet at the damsite to almost 1,300 feet at the highest point.
Upstream of the dar.lsite, the basi n is covered' ,"ith \'let, spongy tundra,
'"hich has a tendency to retain ,"ater and release it over a period of
tine.
T.2.2 Streanflo\ls
The village has hlstorically acquired its water supply from the creek
'"hich flo,"s from the Askinuk r10untains. In 1976, the Public Hea'lth
Service (PHS) built a conmunity h'atersystem that treated the \'Iater \'Iith
chlorine and fluoride. Although the village utilizes a portion of the
creek for "later supply, there are no records of the ar.lount of streamfl0\1
''Ihich has actually occurred. Ouri ng July 1980, a ''later measurement
structure (Parshall Flune) was installed to collect data during the ,
upcomi ng year and to verify the assumed, streamf10\'I val ues. The f1 ume was
installed dO\'lnstrean of the PHS ''later supply intake and consequently,. does
not account for domestic use. The measured f10," at the f1 une ''las
correlated \'lith the streanf10\'l at the proposed dar.lsite to determine the
damsi te di scharges.
Table T .. l sho\'ls the adjusted dar.lsite discharges hased on flo,'Is
r.leasured at the fl ume bet\'leen July 1980 and July 1981.
35
< Table T.l
CORRELATEn OAr1S ITE DISCHARGES (July 1980 -June 1981)
:ftonth
Oct
Nov,
Dec
,Jan
Feb
r.1ar
Apr
r1ay
Jun
,Jul
Aug
Sep
, Oi scharge
( CFS)
1.5
0.9
0.6
0.6
1.1
L2
5.0
10.0
6.0
2.0
2.0
1.4
The above 'r.Jeasured di scharges were taken duri ng a very atypical year
for the area. By correlating~ the general trends in strear:1flo,., with the
, ter.Jperature and rai nfall record-s at Cape Ramonzof Ai r Station 15 r.Ji'les,
a''Iay, revised strearnflO\;,s ,.,ere estimated. Table T.2 belO\., demonstrates
the devi-ati on of August 1980' -nay 1981 from the average. '
Table T.2
MONTHLY RAINFALL AND TEMPERATURE
August 1980 -r1ay 1981
Average Actual Average Actual
Ter.Jperature T enpe ratu re nifference Precipation Precipati on
"onth ( OF) ( OF) fromAvg (i nches) , (i nches)
Aug 49.2 47.2 -2.0 5.00 2. 27 .
Sep 43.7 44.2 +0.5 4.62 3.64 -
Oct 31.1 33. 7 +2.6 2.39 1. 54
Nov 22.6 25.0 +2.4 1.56 0.50
Dec 12.8 8 •. 9 -3.9 1. 21 -0.86
Jan 12.9 19.8 +6.9 1.11 1. 33
-Feb 9.7 . 12.0 +2.3 0.98 1.70
f1ar 13.5 -25.1 +11.6 -1. 25 0.72
Apr 20. 7 27 •. 7 +7.0 0.97 1. 27
f1ay 34.4 42.1 +7.7 1. 28 1.32
The above data indicates that the r.Jonths of August through December.
Here 40 percent dryer that noma 1, ,.,hil e the ter:1peratures averaged' near.
noma1. This indicates that the measured flow is lou. However, the
oPPosite is true for ther.Jonths of January to nay. The prec1patfon was
about 13 percent above noma-' a,nd the tenperature averaged over 7 OF
above normal'for the same flo\'/s. TableT.3 sho,'Is adjusted streamflo\.,
values based on the above considerations. These values \-/ere used \"hen
estir.Jating pO\'/er capabil ities for the hydropower system.
36
Di.fference
fror:1 Avg
-2.73
-0.98
-0.85
-1.06
..;0.35
+0.22
+O~ 72
-0.53
+0.30
+0.04
r10nth
Oct
Nov
Dec
Jan
Feb
'1ar
Apr
'1ay
Jun
Ju1
Aug
Sep
Table T.3·
Adjusted Streamflo\'/s at Damsite
Discharge
(CFS)
*1.8
*1.3
. 1.0
0.7
0.7
0.9
*3.0
*10.0
*fi.O
*2.0
*2.4
*2.0
*Indicates hydropO\·/er system operati ng.
1.2.3 Sedimentation
Difference
from t1easured
+0.3
+0.4
+0.4
+0.1.
-0.4
-0.3
-2.0 o
-1.0 o
+0.4-
+0.6
No sedir.1ent transport studies \'/ere done at Scammon Ray •. The
discharge during the majority of the year is very clear. The only known
tine \'/hen the \'/ater has any sediment entrai ned is dllri ng the spri ng
runoff. The particle si ze is probably fa; rly 1 arge and therefore drops
out of suspension quickly as the velocity decreases. Some minor
rnai ntenance \'/oul d be needed at the damsite on a yearly basi s.
T. 2.4 '. Sno\'l Arid Ice Problems
During the Hinter months, \'Iindb10\'/n snO\'1 is deposited in the ravine
through which the strean flows. In places, the windpacked snow reaches
depths in excess of 10 .feet by the end of ,\'/i nter. '
A site v,i sit duri ng January 1981 found that the sno~1 had a tendency
to drift fron the left sioe to the right, looking downstream. This trend
made the left side sorne\'1hat barren whi.1e the right side had deep
\/indpacked snow. In the nidd1e of the ravine there \'las in excess of 100
inches of snO\'I, ",hile on the left side there \'1as about 36 inches. The
banI-: on the left side had places \'there the tundra was visible. Three
sno\'l samples \'1ere taken slightly upstream of the village and another
three samples taken belo\·, the proposeddamsite. The average water
content \'las 35 percent.
The deep snO\'/ along the strean acts as insulation allo\'1ing the strean
to flm-r(on a restricted basis) \"hen other streams of sini1ar size are
long since frozen. This sar.1e dense snO\:, that provides ;'nslilation also is
subject to creep. ' Because of the creep potential and the fact that
access tf) the penstock \'Iout-;iJ?e restricted for nearly half a year due to
snO\'" a buried penstock is preferred to one located above ground.
37
Specia·l design considerations are necessary to account for 10'" winter
flm'/s, and potential penstock icing problems. These are considered in
more detafl later in the report.
T. ?.. 5 POl'fer Potenti a1 '
Table T-4 provides a sunmary, of the average power potential of 50,
75, 100, a·nd 125 k\.J units. The largest unit provides approximately 63
percent nore energy than the smallest unit on an annual basis. H0\1eve:r,
the bulk of thi s energy is produced duri ng the spri ng and SUmr.1er when it
is not usable. On the ,other hand, the 50 kW unit does not take full
advantage of the available flows and cannot meet projected demands.
r10nth
Oct
Nov
nec
Jan
Feb
r~ar
Apr
t1ay
Jun
Jul
Aug
Sep
Total
Table T.4
Average Capacity and Energy Production
50 kW Unit
kW kWh
50
42
50
50
50
50
.50
50
37,200
30,200
36,000
37,200
36,000
37,200
37,200
36,000
2R7,000
kW
57
42 ----
75
75
75
63
·75
63
75 kl~
kWh
42,400
30,200
------
------
------
------
54,000
55,800
54,000
46,900
55,800
45,400
384,500
100 kW
kW kWh
57
42
90
100
100
63
75
63
42,400
30,200
------
------
------
------
64,900
74,400
72,000
46,900
55,800
45,400
432,000
125 kW
kW kWh
57 42,400
42 30,200
------
------
------
------
90 64,800
125 93,000
125 90,000
63 46,900
' 75 55,800
63 45,500
468,500
To deterrninetheoptimun size turbine, the information in Table T.4
. \'las conpared \/i th the forecast energy demand. The port.i on that was
detemined usable (Table T.·5) \'las evaluated in comparison to the diesel
"base case" as described in Section 4.1.1 Only credit for displaced
energy "las taken, no credit was taken for capacity since the hydrosystem
\'IOuld not function during t'he peak demand nonths of \'linter. These
benefits ; nturn "Jere compared to the cost of the vari ous uni ts and
analyzed over a 50-year period at the Federal di scount rate of 7-5/8
percent. . . .
Table T.5
Esti'mated Yearly Usable Energy
Unit 1983 19l15 ' ~ 990 1995 2000
50 kl~ 239,000 2"'54,000 28J,lJOO 2~00 21tT,ll'00
75 kYI ?39,00O 250,000 306,000 352,000 383,000
100 kU 239,000 258,000 306,000 357,000 393,000
125 kW 239,000 258,000. 306,000 357,000 393,000
Table T. 6 provides a breakdO\'m of costs and benefits for the various
options.
38
. 2010
2'BT,l100
383,000
432,000
454,000
PUBLIC HEALTH SE RVI CE WAT ER SUPP LY
ABOVE SCAMMON BAY
PROPOSED S ITE FOR HYDROEL ECT RIC I NTAKE STR UCT URE
80-82
"
Table T.6
Estim~ted Benefits and Costs
, 50 kW 75 kW 100 kW 125 kW
i, .-
• rEi r.:st Cost ($) 1,073,000 1,106,000 1,130,000 1,155,000' -
Annual Cost
50yrs. 0 7-5/8 ($) 83,900 86,500 08,400 90,4(lO
Operation and r1ain-20,000 20,000 20,000 20,000
, 'tenance (4)
Total Annual Costs ($) 103,900 106,500 108,400 11 0,400
Benefits
Fuel Displacenent ($) 81,200 98,100 103,000 103,200
Operation and Main-
tenance ($)
18,500 . 21,600 22,300 . 22,300
Total Annual Benefits (4) 99,700 119,700 125,300 125,500
BIC 0.96 1.12 1.16 1.14
Net Benefits ($) -4.20.0 13,200 16,900 15,100
Based upon the preceding analysiS, the 100 kW Imitis the optimum
choice for Scar:nnon Bay. It provi des net benefits of $16,'900 -per year
with.a benefit to cost ratio of 1..16 to 1.
T.2.6 Water Supply
ThePub1ic Health Service (PBS) intake for the village's '-later supply
is loc~ted a substantial distance below the proposed damsite. The PHS
recomended a ni ninun f10\'l of 28 gallons per ni nute (GPM or 0.06 CFS) as
required for the water supply. This ''Iould provide approximately 200
gallons per day per capita Hhich is in excess of the normal requirenents
of an urban area. The PUS indicated that they believe the actual
utilization of the syster.l to be bet\feen 50-70 gallons per day per
capita. This ~ifference in system capability and actual utilization
would provide a'margin for development within the COMmunity.
The drainage area beb/een the darnsite and the water supply intake is
0.:; square miles \"hich is tHo-thirds the size of the tributary area to
the dar.lsite. By carrel ati ng thi s 10\'Ier area wi th the upper drai nage
basin an approxir.lation of the "'ater available for domestic use can be
. made as shm-m in Table T.7.
39
T.7
Water,Avai1ab1e for Domestic Use
Available Water
Available Water Available Water From Lower Total Water
Month At Damsite Less Hydropower Basin For Domestic Use
"
Oct 1.8 0 1.2
Nov 1.'2 0 0.9
Dec 1.0 1.0 0.7
Jan 0.7 0.7 0.5
Feb 0.7 0.7 .' ,r,,, " 0.5
f1ar 0.9 0.9 0.6
Apr 3.0 0 2.0
May 10.0 6.6 6.7
Jun 5.0 1.6 3.3
Jul 2.0 0 1.3
Aug 2.4 0 1.3
Sep 2.0 0 1.3
Based on the above analysis, adequate water Would be available
year-around to supply the comunity' s domestic needs. Due to the 1fmitted
operation of the hydropower system, i.e. April through November, the
available water during the critical months of winter is unaffected. If,
for some unforeseen reason, the water supply demand did exceed the
supply, the planned diversion works are, capable of diverting up to 1.2
cfs through the darn on a controlled basis and could be used to supplement
the vi11 age' s water supply if necessary. Duri ng '''Ii nter shut-down due to
low flows, the diversion works would divert all flow through the dam to
supplement the village water supply and prevent ice-up of the dam
reservoir. A detailed explanation of the winter diversion,scheme is
incl uded later in the report.
40
1.2
0.9
1.7
1.2
1.2
1.5
2.0
13.3
4.9
1.3
1.3
1.3
-..
..
T.2.7 Potential Floods
An analysis of data frol:1 noody Creek at Aleknegik (STA. l5-3029-00)
was utilized to estil:1ate potential floods. The drainage area above the
dal:1site at Scamon Day is approxil:1ately 0.75 l:1i 2 whi 1 e the drai nage
area at Moody Creek is 1. 28 l:1i 2. Although !toody Creek does not have
the sar.le coastal i nfl uence that Scammon Bay does, it ''las bel i eved that
rloorly Creek "/as the best stati on in the area to use. Its frequency curve
is illustrated in Figure 5.1 The Sca~on Bay discharges for various
frequencies are illustrated heloH in Table T.R. These discharges \'iere
detemi ned by a cOl:1pari son of the .drai f"!age areas between Scammon Bay and
noody Creek.
T. 2. B Dan Safety
Table T.B
SCN1MON BAY DISCHARGE FREQUENCIES
Return
Internal
(yrs)
200
100
50
25
10
5
2
Di scharge
Q
(cfs)
135
104
82
65
49
39
27
The uneconnended Guidelines for Safety Inspection of Dams,1I provides
general criteria for evaluating the safety of dans. Since the actual
storage is less than 50-acre-feet and the height of the dam is less than
25 feet, the site classification \'/ould be considered "small. u The
failure of the dan HOIJ1d not be expected to cause any ulos s of 1ife u or
cause any lIeconomic ·loss," by flooding. These conclusions result in a
hazard potential classification of 1110\1. II
In actuality, the reservoir storage capacity is so sna11 (approxi-
mately 1/10 acre-foot) that any dam failure would not Significantly
change the dm'instream flow. Any adverse affects on the dan itself due to
flooding ",ould probably be linited to siltation requiring additional
mai ntenance.
The tNO classifications of sna11 size and 1m·, hazard potential result in
a recommendation by the guidelines for a Spillway Design Flood (SDF) of
bet\leen a 50 to lOO-year frequency. A 100-year discharge (104 cfs) was
used.
f~o danage Hould he anticipated at the pO\'lerhouse due to location
above the 100-year f1 oodp 1 a; n. Hm'lever, damage to the vi 11 age water
supply cou1 d be expected \there it crosses the strean be10u the po\'/erhouse
42
si teo T\lo exi sti n9 cul verts pass the streamflo\'l through the road
enbanknent that supports the \later 1; nes. These cul verts are ; nadequate
to pass the design floH.
43
. .--'~'---'---'" ... _._-----_ ... _ ..... _--1 000 ~9.99 99.9 99.8 99 98 95 90 80 70
·No tes: 900~ 1. Data collected at USGS Stream Gaging
800' Station, 15-30290 for the Period of
... 9
700 i Record 1969-1979' (lO·years). 1974
, \~ ate rye arm iss i n 9 and t rea ted (1 eft 600i • 0 u t) a s a b r 0 k en r e co r d a s i 11 u s t rat e d
500! . i n B u 1 1 e tin 1 7, p. 14 .
. 2~ program 723-K5-L2540 was utilized to
2
.. --
. 0.05 0.1 ~~~~~~~~--__________ ~ __ ~~ __ ~ ____ ~ 1
50 80 90 95 1198' 99' 99.99
..
T.3 GEOLOGY
T.3.1Project Site Geology
Local rock is a granodiorite intrusive of probable Tertiary Age.
Deep \'Ieathering, jointing, exfoliation and/or frost spal1ing have
produced'surface boulder fields and thin silty soil. Unsorted glacial
overburden overlies the granodiorite bedrock in the project area. The
overburden represents ground moraine \'Iith interdispersed \'/ater-lain
deposit. The glacial overburden consists of gravel and sand containing
nu~erous cobbles and boulders. Go~position of the gravel t cobbles, and
boulders is primarily granitic. The granodiorite bedrock and granitic
glacial overburden \-/eathers quite rapidly due to the climate and mineral-
ogical composition. The glacial overburden varies in thickness through-
out the area due to the undulating granitic bedrock surface. In the
vicinity of the damsite at the 600-foot elevation, the overburden 'is
apprOXimately 8 to 10 feet thick. Near the powerhouse site, overburden
varies beb/een 6 and 20 feet. Overburden thicknesses \1ere determined
using refraction seismology.
Permafrost is absent to sporadic \1ithin the immediate project areas.
The perenni al spri ng-fed stream and the predictable thick ; nsul ati on
bl anket of drifted \,/i nter snOtI \'Ii thi n the stream gully resul ts ina tha"l
zone beneath and adjacent to the stream. Outside of the gully, the
surroundi ng area is underl ai n by conti nlJous pemafrost.
Oank erosion is prevalent on streambank slopes beb/een the village
and its \'later supply intake. This is probably due to sumer thaw of the
active layer. The \'/est bank of the stream, between the village and water
supp ly intake, has a 10\;1 profil e due to subdued erosi on. Thi s condi ti on
probably causes thi.nner winter sno\'I drifts to accumulate inthe area,'
hence more exposure to prolonged be10\1 freezi ng ter:1peratures.
The powerhouse site is located in an area above the stream'where
soli fucti on does not appear to be a probl em •.
T. 3. 2 t1ateri al Sources
The borro\'l area; located on the east edge of Scamnon Bay, \-/as sarnp 1 ed
and tested for qual ity of concrete aggregate. Ana1ysi s of the test '
results ~.ndicated that the fine and coarse aggregates are of relatively
poor qual ity and will not r:1eet Corps' standards for approval. The
exposed granodiorite outcrop near the site could possibly produce quality
aggregate, however, more testing is needed.
T.4 ONl t SPILLWAY, AND ItJTAKE
T.4.l Description
The dan \"ould be constructed of rockfi11ed gabions arranged around a
cutoff \'tall \,/hich extends into bedrock. This cutoff \..,a11 \"ou1d be
45
constructed of sackcrete and extend approximately 9 feet belo", the
existing ground surface and about 4 feet be1m'l the gabions. Descriptions
of the dam, intake, penstock and pm"erhouse can be found on the attached
Pl ates.
The dam \-/ould have a crest length of 48 feet and a maximuM height
froM bedrock to 15 feet. The nonoverf1 m" section of thi s gravity
structure Nould have a top elevation of 600 feet. The ungated \'Ieir
overflm-I section \'1ould have a total length of 13.5 feet at elevation
598. OverflO\'1 from the \'Ieir \-,ould enter the existing streanbed. The dam
\'1ou1 d consi st of a rm'l of standard manufactured galva ni zed steel gabi ons
on each side of the cutoff "/a11 set dm'ln into the existing streambed.
The gabions ,,,ou1d be filled \'Iith rocks taken from the reservoir
excavati on .and the nearby area.
The intake structilre \-lOuld be a square r:1eta1 dropbox set vertically
on the right bank. A french drain system would run from the left side of
the intake to the left abutMent. The french drain \"Iou1d consist of clean
gravel which would allow flows to enter a perforated pipe in the drain
and be carried through the dam via a r:1eta1 pipe. A blind flange would be
mounted on the drain pipe inside the intake structure to allow access for
maintenance and entrance of 10\'1 flows to supp1er:1ent power production. A
gate valve would be mounted on the drain pipe inside the intake structure
to alloH regulation of f1m-1 through the dam. A 2-foot by 2.5-foot
trashrack would be mounted in the side of the intake structure below the
elevation of the overflou section. A movable bulkhead would be mounted
above the trashrack intake. This \"ou1d be 10\,/ered to de\'1ater the intake
or to shutoff the intake during winter shutdown. The grating of the
trashrack would be coated with a hydrophobic fluorocarbon to reduce
icing .. A USGS-style gage house would be placed on top of the intake
structure to keep it free of snow and to allow access during periods of
deep snON. A ladder \lould be installed inside the structure to allow
access to the valves and instrumentation, which would be located inside
the structure.
T.4.2 Flushing System
The ; ntake structure \'/ou1 d not have a fl ushi ng system because of its
small size. The reservoir bottom would be sloped away from the intake
tOHard the center of the excavated reservoir to prevent rocks and other
debris from accur:1ulating around the intake. If excessive material does
build up in the channel, the reservoir could he drawn dm'ln and the
material removed by hand or with a small tractor.
T.4.3 Hydraulic Oesign
The Hei r overf10\'l secti on in the rock gabi on dam is des; gned to pass
the 100-year f1m'i. The overf10\,/ section is 2 feet high and 13.5 feet
long.
The intake structure is designed to operate year-round regardless of
floH. During the \'/amer months when flo\,/s are capable of exceeding the
pO\ler requ; rer:1ents, the \'later \'Iou1d f10\'1 through the trashrack and; nto
the penstock \'/ith excess f10\'/ bei ng passed over the wei r.
46
".
When the system is shut dOl'!n in the winter, all flows would be
diverted through the dam via the french drain, perforated CMP and drain
pipe. This drain pipe ''Iould teminate in another french drain do\'mstream
of the dam to prevent freezing.
"' During \'linter operations much of the intake would be covered with
snow; however, to what extent is unknown. Anchor ice could form on the
penstock, diversion pipe and valves. When the hydropower system is
shutdown,lthe penstock would be drained to prevent possible catastrophic
failure caused by freezing.
T.4.4 Operation
Automatic shutoff of the system at a power output of less than 15 kW
\-/ould be designed into the turbine/generator unit. It would also be
designed into the manual operation of the plant. When streamflow drops
below 0.63 cfs, the minimum needle valve setting for the turbine, any
further drop in streamflOl'! ''Iou1d result in a decrease in head. When net
head becomes low enough, power output wo'u1d drop below 15 kW and the
system would shut down automatically; first the jet deflector would
divert the flow a''Iay from the turbine runner, then the needle valve would
close slQ''11y (25 seconds). System shutdown (15 kW output) would occur
when gross head reaches about 430 feet and discharge about 0.54 cfs.
Since the turbine control mechanism has no way of knowning when the
streamflow is high or low, a mannua1 setting of the nozzle for an output
of O~ 63 cfs" with a gross head of 485 feet must be built into the system
and must be activated by the operator '''hen streamflow is in the 0.6 to
0.7 cfs range.
The same type of manual control must be built in for moderate and
high flows since regulation of inflo\'I by load demand alone could cause
the penstock into drain unnecessarily. A fail-safe mechanism should also
be incorporated into the turbine-generator system penstock drainage in
case of operation error or negligence.
T.4.5 Dewatering of Intake Structure
The intake structure would be de,,,atere'd to the penstock invert by
lowering the bulkhead and releasing water through the penstock. ~1inor
maintenance could be done at this time and complete "de''1atering by pumping
or other means would allow any major maintenance work.
T. 5 PENSTOCK
T.5.1 Description
The penstock \'IOuld be buried throughout its length. It would run
within the confines of the ravine through which the stream flows. The
streambed is generally a composition of gravel, cobbles, and boulders
that vary from 6 to 20 feet in depth with some outcrops of bedrock. The
groundline along the stream bottom has an average slope of 13.5 percent.
The penstock ,,,ou1d cross from the right bank to the left bank of the
stream ahout 550 feet dOl'Instrearn of the darn. The vegetation cover in the
streambed is minimal.
47
The penstock ~/ou1d be a 12-inch inside diameter steel pipe extending
3,SOO'feet from the intake invert at the at 589-foot elevation 11 feet
be10\" the top of the dam to the pO\'terhouse at 110 feet. rhe project
gross head is 48S feet. A 12-inch diameter manually operated gate valve
in the intake structure would allow the penstock to be drained during
winter low-flow conditions and during maintenance. A 1-7/B-inch diameter
air vent would extend from the penstock immediately downstream of the
gate valve up through the gatehouse to the open atmosphere. A screen
\'Iould cover the upstream end of the gate valve to insure that no small
objects are dra\"m into the penstock.
The penstock would be deSigned for a minimum working pressure of 440
psi with a minimum wall thickness of 0.172 inches. The penstock would be
completely encased in select bedding material to insure against point
loading that could develop with boulders and bedrock.
In periods ,of cold weather, the do\"mstream valve at the powerhouse
\'1ou1 d have, to remai n open unti 1 the penstock was completely drai ned.
Penstock drainage would be accomplished by closing the upstream valve to
the penstock and allowing the \'1ater to drain by deflecting the water away
froM the buckets of the impu1 se turbi nee Thi s \'1as detemi ned to be the
most fool proof and cost effective method to avoid penstock freezing.
Insulation of the penstock flas considered, but \.,ould only delay the
freeze-up for a few hours.
T.6 POHEI1HOUSE
T.6.1 Description
The 100 kW unit would have all equipment housed in a 10' x 11'
prefabricated, i nsul ated, \'leather ti ght, steel structure, bui lt on a
12-inch concrete slab. The pO\'1erhouse would be located at elevation 110,
the finished floor elevation being 4 feet above the maximum taih'later
level. An open channel tailrace \'IOuld be excavated below the
powerhouse.
Ventilation \"ould be provided by a wall mounted fan. Two fire
extinguishers \'Iould provide fire protection to the building; none would
be provided for the generator. A \'1eather tight, roll-Up door would allO\'1
access for equipment installation. A 5-ton underhung crane \'1ou1d be
installed for equipment handling. The attached plates provide a layout
of the proposed powerhouse. '
T.6.2 Turbine, Generators, And Electrical Description
The hYdroelectric pO\'1er generation equipment \"ould be procured as a
package unit. It \"ould consi st of one impul se turbi net a synchronous
generator, governor system, voltage regulator, and protective and control
devices. lInits of this type are readily available from industry, either
as pre-engineered standard or custom rlesigns. covering a wide range of
heads and flO\'1s, connected loads, and operating conditions. In addition
to bei ng economical and siMp1 ifyi ng installation, package unit
procurement reduces the nur.lber of supply contracts from three or four to
only one.
48
The 100 kW turbine "/ou1d be a "standardized" horizontal axis impluse
or Turgo ir.1p1use, turbine \lith one or triO adjustah1e nozzles.' The nozzles
would be actuated by servomotors controlled by the governor. Jet
deflectors \'Iou1d be used for diversion of water from the runner for rapid
load change, load rejection, or pen$tock draining. A cylinder actuated
butterfly valve in the penstock \'Iould be provided for shutoff of the
water. The IJnitwould be specified to produce pOlter over a range of 15
to 100 kt4 "'hen operati ng at 430 feet net head. The expected di scharge
from the turbine at maximum pO\'ler is estimated to be 3.4 cfs, and 0.63
cfs at r.1ir.1ir.1lJrn pO\'ler (15 kH).A flYh'heel \'Iould he provided, if
necessary, to limit speed excursions dur'ing load changes. The turbine
\,/ou1d drive a generator through V-Belts and a parallel shaft gearboxe, or
through adi rect connection to the generator. The choice of the
operati ng speed and power transr.1i ssi on system Hou1 d he 1 eft to the
manufacturer. If the gearbox or V-Belt drives \'1ere used ho\tever, a 4
percent efficiency loss \'/ould be charged to the turbine in the
determi nati on of its guaranteed perfomance c haracteri stic.
The governor syster.1 \'IOU 1 d be furni shed as an integral part of the
turbi ne-generator package unit. The governor system \'1ould be composed of
electronic speed sensitive elements (frequency transducer, controller,
and amplifier), a servo syster.1 consisting of either electric motor and
gears or hydraul ic pimp and electric motor, and the necessary control s.
Responding to fluctuations in p0\1er der.1and, the governor would actuate
the needle vah'e in the \later supply line, control the amount of \'/ater
supplied to the turbine and regulate the speed of the unit. The governor
size and characteristics (capacity and speed regulation) would be '
detemined by the nanufacturer, 'based on head, WR2, speed, and pO\'ler of
the unit.
The synchronous generator \'IOU 1 d be, provi ded as part of the pac kage
uni t. The generator speed and coup1 i ng to the turbi ne \-lOu1 d be
detemi ned by the r.1anufacturer based on the operati ona1 requi rements.
The generator, which should be provided with special bearing and
lubricants suitable for operation in extended 10\'1 ter.1peratures, \'!ou1d be
rated single phase, 60 Hz, 100 kW (125 kVA @ 0.8 pf), 120/240 volts \'lith
full Class F therlJa1 capacity (Class R temperature rise) and be capable
of continuous operation at 110 percent overload and + 5 percent of rated
voltage. The generator \'Iou1d be equipped \'/ith a brushless, full wave
rotating rectifier excitation system and a saturable transformer type
automat; c voltage regulator \'Ii th a response tir.1e of 200 rni 111 seconds,
capable of regulation of one percent from no-load to full-load. The
generator ",ould also be furnished \'lith a control and protection equipment
group. This consists of a circuit breaker (\'/ith shunt-coil type,
under-and-over voltage relays, overcurrrent relay, stator thermal relay,
instantaneous ground relay, rec10sing relay, and lockout device), an
anneter, \latt-hour neter, \'/attmeter, volt-r.1eter, frequency meters, and
indicator lights for manual synchronization. In order to prevent
r.1oisture build-up, it may he necessary to partially energize the system
during winter shut-down.
49
The g~nerator bus \<loul d be tapped between the generator ci rcuit
breaker and the step-up transforr.1er to provi de three-\'/i re, si ngl e phase
120/240 volts to a lighting distribution panel for service station
lighting, convenient outlets, a ventilating fan, and other r.1iscellaneous
loads.
The r.1ain power transfomer ",ould be single phase, 120/240 volt
prinary, 1-2,470/7200 volt secondary, 15 kV class, dry type, and
ventilated. It \'Iou1d be floor mounted in the pO\,/erhouse.
The generator, excitation, breaker, and turbine controls \"ou1d be
mounted on the governor equipnent cabinet. Controls would be included to
nanually synchronize the excited unit to the line. t1etering \>/ould be
provided for volts, amps, vars and \'/atts. The generators \'lOuld be
provided with voltage restraint overcurrent and overvoltage relays.
Underfrequency and overfreqllency protection of customer equipment would
be provi ded ''lith speed switches and SOr.1e form of automatic time error
control Houl d he cons1 dered.
T.7 TRANSrUSSION SYSTEr1
The electrical connection to the existing distribution system "/ould
be by 15 kV, No. 2 AWG al umi num conductor on ,,,ood poles from the
"ta11-nounted ueatherhead fitting at the pm'/erhouse to the existing 7.2 kV
primary capable in the surface-mounted duct bank. Rigid steel conduit.
\-!ou1d he used to run the cable fron the teminal pole to a pad nounted
tenninal cabinet installed· in the duct bank.
T.B ALTERNATIVE DESIGNS CONSIDERED
T.B.l Dan
Various types of dar.1s uere considered, but due to renoteness, lack of
material sources, and cost they were ruled out. Alternatives considered
included concrete (good aggregate source unavailable), earthfill (access
di ffi cul ti es and 1 imi ted borr0\1 materi a 1 ), and timber (no 1 oca 1 source
and potential snO\'/ creep problems). The chosen alternative, rock filled
gabions is suitable for the small size of the dam. Also the availability
of suitahle sized rock in the project area is good.
A sackcrete cut-off to bedrock \'las used for estimating purposesj
hmfever thi s nay be changed to a nemhrane cut-off duri ng the preparati on
of plans and specifications.
T.O.2 Penstock Alternatives
An above ground penstock \'las considered in addition to the
reconnended buried penstock. The buried scheme was selected because it
would present less long terr.1 problems. It \'/ollld be less susceptable to
vandal i sn, sno\'l creep, freezi ng and streaM activity.'
50
The following pipe materials or combinations of pipe materials \"ere
consi dered for both above and underground install ati on:
1. Schedule 40 steel entire length
2. 0.172 inch steel entire length
3. High density polyethylene + Schedule 40
4. High density polyethylene + 0.172 inch steel
S. Reinforced plastic mortar pipe entire length
Underground install ation of 0.172 steel penstock and rei nforced
plastic mortar (RPrl) pipe were found to be the least costly alterna-
ti ves. The steel penstock \'/aS chosen because it presents less unknowns
regarding installation and bedding. The remoteness of the location,
potential difficulties in bedding, high Horking pressures and general
durability ''Iere factors considered in pipe selection.
T.8.3 PO\'lerhouse
flue to the linited flO\'1 and high head, the only suitable turbine type
is an inpluse turbine. Various sized turbines of SO, 75, 100, and 125 kW
\"ere considered. In addition, tuo 50 kW units \'-/ere proviously considered,
but \'/ere not found to be cost effecti ve, si nce one uni t can functi on
efficiently over the \,thole range of possible flo\'ls. The 100 kW unit was
found to be the optimun choice based of the parameters of flow, energy
denand and fuel costs.
T.9 CONSTRUCTION PROCEDURES
Due to the delicate nature of the peroafrost areas near the project,
special care \'Iould be necessary to assure that these areas are not
disturbed unnecessarily. Tracked vehicles brought in by the State of
Alaska to construct the runway in the early 1970's crossed the permafrost
above tOt," "'hen it \'las unfrozen. Thi s di srupti on of the vegetative cover
reduced its insulating capabilities resulting in the melting of the
pernafrost. This melting has caused additional loss of vegetation and
further melting, resulting in the erosion of gullies nearly 6 feet deep.
For constructi on of the hydroproject, access ''1oul d be 1 imi ted to the
confines of the ravines through Nhich the stream flm'ls. This area ;s
underl ai n by a tha\,fhul bin the pemafrost. Access over permafrost areas
may be a 11 o\'led for stagi ng materi a 1 sand equi pment if; t were done duri ng
\'Ii nter when acceptable conditions of frozen ground and adequate snow
cover exist.
An equipment access plan \-,ould be incorporated into the contract
documents. This plan ''1ould delineate construction corridors for both
sumner and \Ii nter access.
1. 10 PROJECT OPEnATION ANO t1AINTENANCE
Once constructed the proj ect \'foul d probably be turned over to the
local utility for operation and maintenance in conjunction \'1ith the
existing rliesel generators. It Hould be the responsibility of the
51
PERMAFROST EROSION DURING AIRPORT
CONSTRUCTION
utility for all maintenance associated with the intake works, penstock,
pO\'lerhouse and di stri bution systerl. In addition, spri ng startup and
"tinter shutdO\"n including penstock drainage would be required.
The unit ,,,ould be capah1e of rlatching the necessary load during the
time of year '''hen flO\'Is equal or exceed the der.1and. Ouri n9 those low
f10\'1 tirles "hen energy deJ71and exceeds the capabil iti es of the system, the
hydropOl'ler unit -''Iould operate in a base load r:lode ,,,hile the diesel "/ould
be utilized for peaking.
T.11 PROJECT COST
ITEtl OESCr.IPTION
"108 & PI1EP WOI1K
LIVIDS & OAI1AGES
Administrative Costs
Lands
OAt, & SILL
Exc(\vation
Sackcrete
I:ei nforcer.tent
Gabion
l10ck
Backfill
Drain pipe 12" 0
French Orai n
I ~JTAKE STRUCTURE
QUANTITY
1
1
1
220
48
2,400
216
144
18
90
17
Steel Intake 1,224
Bulkhead Gate
Trashrack 100
Transducer 1
nanoMeter 1
Sluce Gate 2
Insulated Structure 1
\
PENSTOCK
Stp.e1 (1211 0,
0.172" thick)
11; n9 Stiffeners,
Expansion
Anchors, Anchor
Supports
Concrete Anchor
and Thrust Blocks
Excavation
Backfi 11
70,500
4,900
30
1,020
920
53
lI~1 IT
LS
LS
LS
CY
CY
LB
EA
CY
CY
EF
CY
LR
LS
U1
EA
EA
EA
EA
LR
Ul
CY
CY
CY
UNIT PRICE
20
600
1.30
90
110
10
25
50
2.50
3.00
3,500
2.00
2.00
600
15
8
TOTAL
$300,000
$1,000
4,000 S5,ooo
$ 4,400
28,800
3,120
19,440
15,840
180
2,250
.: 850
$74,880
$ 3,060
5,000
300
$ 5,000
$ 2,000
7,000
6:,000
$28, 360
$140,000
9,800
18,000
15.,300
7,360
$190,460
ITEr1 DESCfHPTION
POHERHOUS£
Structure
Turbines &
Generators
Auxiliary Systens
Sl'litchy;ard and
Distribution
SysteM Connection
. \ .
TAILRACE
Excavati on
ftiprap
SUBTOTAL
20 Percent Contigencies
CONTRACT ~OST
QUANT;IrY
LS
LS
LS
LS
45
15
Engineering and Design
Supervision and Administration
TOTAL PP.01.1ECT COST
T. 1 2 PftOJ . .ECT ECONOr1 IeS
T.12.1 FeaeralCriteria
UNIT
1
1
CY
CY
UNIT PRICE
20
110
TOTAL
$ 40,'000
135,LOOO
16,000
25,.s00
$216,;pOO
$ 900
1,.650
$2,550
$817,750
163,550
$981 J 300 , .
$ 70,000
78,700 .
$1,130,000
Under criteri a establ i shed for Federal water resource projects, th~
Selected Nan is feas'ible. Factors influencing the feasibility have been
presented in appropriate sections of the report. The results are
p resented be 10\'/ :
ANNUAL COSTS AND BENEFITS
Intere~t and Amortization (7-5/8 percent, 50 yr.)
Operati on and 11ai ntenance
Total ~nnua1 Cost
Fuel Oisp1ace~ent Benefit
Fuel Cost Escalation Benefit
Operation and r1ai ntenance Ilenefit
Total ~nnual Benefit
Net Annual Benefit
Benefi~-Cost Ratio
54
$ 88,400
20,000
$108,400
$ 62,900
40,100
22,300
$125, 300
$16,900
1.16 to· 1
0;;
..
T.l2.2 State Of Alaska Econonic Criteria
The State of Alaska, Division of Budget and f1anager.1ent in the
Governor's Office has requested that the Corps incorporate the State IS
econonic criteria into the hydropOlter process. This will allo\'/ the State
to better deternine if their participation in a potential project is
justified.
The State of Alaska1s hydropower economic criteria for FY 82,
1 July 1981 to 30 June 1982, is summarized below:
Inflation Rate
Discount Rate (50 years)
Petroleun Fuel Escalation
o Percent
3 Percent
2.6 Percent (20 years)
Based.on the above criteria and the sa~e energy usage as assur.1ed for
the Federal evaluation renders the results shO\tn bel 0\'1:
ANNUAL COSTS AND BENEFITS
Interest and Amortization (3 percent 50 yrs)
Operation and Uai ntenance
Total Annual Cost
Fuel Displacement Benefit
Fuel Escalation Renefit
Operation and f-1ai ntenance Benefit
Total Annual Benefit
Net Annual Benefit
Benefit-Cost Ratio
55
$43,900
20,000
$63, 900
$ 66,800
31,900
23,600
$122,300
$58,400
1. 91 to 1
•
CORPS Of ENGINEERS
CAPE
ROMAN.ZOF
BAY
\
, l \
( ~
\...ASKINUK j : (" ~ MOUNTAINS '--'"'-.J,
~~-)}I
~~ v
VICINITY MAP
SCAL E I ,". I MILE
ASKINUK MO UN T A INS
~7'<f -
~\>~ ":;:'~ C LARENCE R H ODE l.._".. NATI ONAL WILDLIFE RANGE
LOCATION MAP-
ALASKA OI5mICT
CORPS OF ENGINEERS
ANCHORAGE. ALASKA
him=---' SCAMMON BAY , ALASKA
HYDROELECTRIC PROJECT
1"/;ID!l""':~-'
LOCATION a VICINITY MAP
"""-,,AS SHOWN 1M'"
INY. NO. DACW85-
U . S. ARMY
CORPS OF ENGINEERS
~\
'2.\
----
ALASKA DISTRICT
CORP'S OF ENGINUIItS
ANCHORAGE. A1...ASKA
SCAMMON BAY. ALASKA R~h.m:,a:-----1 HYDROEL ECTRIC PROJECT
GENERAL PLAN
SHHT OF
U. S. ARMY
2000Q
CORPS Of ENGINEERS
.I
;"
DAM LOCATION -PleNd
"CAL£' : I" , 10'-0"
00' , ",' ,
'" /
/
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-'"
UPSTREAM ~L-EVATI ON
5CAL.E< , V1 " ~ 1'-0"
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12" ¢ DRAJ"N
ALASKA DISTRICT
COR~ ()IF ENOIN~
ANCHOIUoGE. ALA8KA
SCAMMON BAY, ALASKA
hr.:=--"" HYDROELECTRIC PROJECT
'-_.....,;~""I DAM AND INTAKE STRUCTURE
PLAN. ELEVATION. a DETAIL
INY. NO. DACW85-
U. S. ARMY
CORPS OF ENGINEERS
-~
HOlJ?E ------
F'iO N<ST<la \IAl.ve
CONTIi'OL.
,"~"'I O~ PiPe; ---
VAl-VE ~nI'O l-
~K.-----,
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rOPOF DA~ a · (,00.0
PIS" D~. Af~ ~Nr
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I5UUC HeAP
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VAl-VI:.
1"2' ~ PE£FOI<ATEW.--!"""'..>.....u
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TYP ICAL
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I
1-------1., :
S l -Oll
a.S6'l>.o
0f'ILLWAY SEcTION
'5CAL.E : 1/1 " s 11 .0"
o 7' l ' 1
12" ¢ l-foN F"l-foN
Dlv~<;;I ()1oJ PIPE>
·0.0
SECTIO t-J
(,0'-0"
c.LA%lFIIW ----"'I,~
~FIL-L-'7<;9f,
C01PACTION
5~crIOt-J
~l..-E; : 1" ~ 1'-0'1
ALASKA DISTRICT
COftN 0" I[NQIH~
ANCHOftA.QE, A1..AMA
SCAMMON BAY. ALASKA
I... ..... ---l HYDROELECTRIC PROJECT
1-.._,.....:>/iII.~ DAM AND INTAKE STRUCTURE
SECTIONS
INV. NO. DACW85·
""""AS SHOWN ..... ... -
U. S . ARMY
CORPS OF ENGINEERS
..
i
i
'0 .... . .
M \C. 'r.W .
CJ:,'-Ol , 9',
~: !Y4" '/-0"
o
!
i
!
TAIl.f',~ DETAllh
TO ,?UIT <?liE
11~O'
of iE<IOWl!flA"TO,",
100 K'" 120/240 V~,
<1>0 Hz, I¢
fll'>E ------,
EX'1"I~I"HI!!I'>
PLAfJ 1-100 KW UhJlT
<?.:::;,o...L.e::?f4,u w l'-oli
2' !
.t
!
PO\VWI'>PL~~--TOO K W.
~eAD -~~ .
ALASKA DISTRICT
CORPS OF" ENGINEERS
ANCHORAGE. Al..ASKA
SCAMMON BAY, ALASKA
h...."...---1HYDROELECTRIC PROJECT
"",,_,....J;.,c;.-ISCAMMON BAY POWERHOUSE
U. S. ARMY
TRANSVERSE SECTION AND PLAN
5CALI. AS SHOWN DAn. ... -
INV. NO. DACW85-
•
;.
•
, .
In accordance "lith the National Envi ronmenta1 Pol icy Act of 1969, as
amended, the Alas,kaDistrict, Corps,of"Eng~neers,: has assessed the"',
envi ronmenta1)mpacts of the. foll oNi ng actj on: .
Sr1ALL HYD'ROELECTRIC PROJ'ECT
" " '; .
. SCAmmtL BAY, ALASKA'
Hydroelectric power would be developed fron the strean that originates
south of ScamMon Bay, and flows through "the ,village.' The stream flows "
from approximately"elevatio,n800 to elevation 50'where it merges with the
mal n channel· of the Kun.River. A'small reservo; r, with less than
one-tenth, oTan· ac re~foot of storage,., wou1 d be excavated upstream of a, , " ,
rock-filler.! gablO!) dam, . which ,,,ould be· constructed ~/ith a 'crest elevation
of 600 feet. A penstock woul d run 3500 feet from the intake structu·re of
the dam ·to an aboveground powerhouse with an installed capacity'of roo '
kW. An 'open channel tailrace, approxiMately 50 feet in length, \"ou1d be
excavated from ,the, pm1erhouse to, the \Mai n;streaM channel.' .'
The estimated flows at,the damsite display' a high discharge of 10 cubic
feet per second {cfs} in J1ay'with a low' of 0.7 cfs duri ng January and,
Fe\'lruary. These flo\'ls could develop about 432,000 kWh of electr.icity,
annually, of which 239,000 kWh is estimated to be usable the first year
of operati on. '
" ~ ;
Sca~on Bay is totally dependent upon fuel oil for space and water
heati ng and e]ectrical generation. Increases in fuel prices have been
the principle source of the rish)gcosts of electrical, power. The
average cost of diesel fuel delivered. to Scammon Bay has increased over
360 percent si nce 19.73. ,Future del11and and scarcity of petrochemical
products wi 11 c~use conti nued price increases.
The Environnenta1 Assessment indicates no significant adverse impacts
\10uld occur during the construction Qr the operatton and mal ntenance of
the proposed project. ,A letter of intent ,to prepare a Finding Of No
Significant Impact (FONS!) for the pf:oposed, project \.,as ,distributed to
the resource agencies for their ,review and cOr.1l'!1ent. None of the agencies
indicated any objection to the preparation of a FONSI. The Environmental
Protection Agency and the U.S. Fish and Wildlife Service stated'the '; ,
nagnitudeof the, project and the low levels of ,wildlife resources in the
pro.ject area el imi nated the need for an envi ronmenta1 impact statement.
The envi ronmental revie\'1 process has indicated to me that the proposed
action does not constitute a najor Federal action significantly affecting
the qual ity of the hUman envi ronment., Therefore, an envi ronmental impact
statement\1fll not be prepared for the small hydroelectric project at l ,
Seamon Bay, Alaska .. Also, the proposed action does not appear.to
conflict'\,/ith the approved Alaska Coasta}'Management Program or any other
appropriate regulation or program. The Environmental Assessment that has
addressed the proposed action is available frOM the District Office upon
request.
ENVIRON~,1ENTAL ASSESSMENT
NEED Fon THE PROPOSED ACTION
The Corps: of Engi neers' \.,as authori zed by Congress to conduct
feasibility studies for the development of small hydroelectric power
facilities at isolated villages throughout Alaska. The village of
Scamon Bay requested that the Alaska Oi stri ct study the hydropO\'ler
potenti a1 of a sr.1all, unnar.1ed spri ng-fed streaci that runs through thei r
village. '
Scanno,n Ray, a r.1enber of the Alaska Village Electric Cooperative,
Inc. (AVEC'), is totally dependent' upon'dies~' generation for electric
po\'1er. Recause of the escalating cost of diesel fuel and concern over
its availabil ity, alternative pO\'ler sources, such as hydroelectric pO\,ler,
could be more econor.1ica1 and reduce the use of nonrene\'/able resources.
COORDINATIQN AND PUBLIC INPUT·
The following agencies, interest groups, and individuals were
consulted during the feasibtlity study for the Scar.1r.1on Bay hydroelectric
project: U.S. 'Fi'sh and Wi1dl1·fe Serv;:ce; A1a~ka Department of Fish and
Game; Alaska Power Authority; Public Health Service; Bureau of Indian
Affairs; Northern Technica" Services (NflRTEC); AVEC; Honer Hunter, r1ayor
of Scamnon(Bay; and residents of Scammon Bay. '
RELATIONSHIIP TO ENVIRONt1ENJAL REQU:IREt1ENTS
This dpcument wa,s prepa'red under the guidelines of the National
Envi ronmental Policy Act. established by the: Counsel on Envi ronmenta'l
Quality. The docunent:is in full compliance' with Federal and State of
Alaska regiJlat1 ons " \'/i th the· except; on' of theC1 ean Water Act, Coastal
Zone r1anagement Act, and State \4ater Quality Certification, which will be
met upon completion of .the final document review. ' '
The U.S. Fish, and l~;TdTHe Service prov;'deda Coordination Act Report
as per the' Fi sh' and Wi 1 dH,fe Coordinati on Act of 1958. An exec uti ve '
SUr.1r.1ary of the report i sincluded in the Appendix. Copies of the enUre ,
Coordi nation Act Report are avai 1 ab1 e upon request.
The Envi rc)nr.lenta1 Assessment, \"Ias prepared to address the' ,
considerations,outTi'ned in' Section '404(b)(l) of the C1eariWater Act anCt a
separate evaluation, ;.s not' 'included.
J\L TEnNA TI VES
The Corps of Engineers is authori zed to study the feasi bi 1 i ty of
hydroelectric a1ternatives'and" if warranted, recommend them to Congress
for construction authorization. Nonhydroe1ectric a,lternatives ~re also,
assessed;ho\'lever, the Corps of Engineers is not involved in their design
or constructi on.
2
...
...
•
Hi nd Generati on
Continuous "lind recordings'are available fror.1 Cape Ronanzof,
approxiMately 14 Miles \'Ie,st,ofScamnon Bay. on the, south side of the,
Askinuk r10untains. tHnd;:di~ectfon varies, but'~'vd:nd from the northeast is
the most common. Because of the northeasterly ''Ii nds, Scammon Bay ,may
experi enee a hi gherHi nd regime than Cape ,Romanzof due, to its geographic
location on. the north side of the mountain range. , Although no \-/ind data
have beencollecte~ at, the village, residents state that they experience
high \'I;,nds, 'for 1 ong durations, parti cul a.rly duri ng the \'Ii nter. Before
they joined AVEC, Hind;generation ,''las used by t\tO households. Based on
the i nterpretati on' of Cape Romanzof ''Ii nd data, it appears that there is
sufficientwtnd, of bO,th magnitude and duration, to supply, Stamon Bay ,
\1ith a portion of their electrical energy needs duri ng the ~/i nte~. .The'
feasi bil fty of wi nd generati on duri ng the summer is questi oriabl e because
of the lO\'ler average 'lind velocities at that time.
Existing Conditions (Diesel)
Scamon 'B~y presently derives electrical pm'/er from .diesel-fi red
generation. The system provigesyear~round dependable power and meets
the needs of-the comunity. The econoMic feasibil'ity ,of continued diesel
use is quest,ionable because of increasing prices and possibly declining
availab,ility. The future costs of prorlucing'electrical po\'Ier fror.1 diesel
in rural Alaska r.1ay hecome prohibitive.,
Other alternative energy sources include solar, Haste neat recovery,
geothernal, coal, peat, tinber, municipal solid 'taste, and tidal. Of
these altenatives, geothermal, coal, peat, and timber are not feasible
due to the lack of these resources in the immediate area. Scammon Bay's
location on the north side of the mountains Makes solar energy infea~ible
for r.1ost of the year. ~ecoverable waste heat from AVEC's diesel, '
generation could produce 2,090 million Btu's per year. This alternative
\'lOuld require the continued use ,of diesel generation and the design -of an
adequate transl)1i ssi on system. If di esel -generation conti nues, thi s
alternative may be a viable energy source for space heating. r1unicipal
solid 'taste could produce up to 626 ni11ion Btu's per year and provide 5
percent of thecomunity's present fuel input requirenent. Effective
generation fron tidal po\'/errequ;re~ a,minil11um head of approximatel.x 10
feet. Daily tides at the project area are ,about 6 to 7 feet. Coupled
'-lith the lack of ninimum head and, the icing conditions of Scammon Bay,
this alt~rna:tive does not appear 'to be feasible.
Hydroelectric (Selected Alternative)
Hydroelectric pO\'ler tlOuld be developed' from a spring-fed stream
located south of the tOl'1n of Scanr.1on Bay. The stream flo\'IS from
approxir.1ately elevation 800 to eleyation 50, \'/here it merges with the
Mai n channel of the Kun Ri ver. A sMall. reservoi r ",oul rl be excavated
upstrear.1 of a rock-filled gabion dam, \'1hich''Iould be constructed at
elevation 596 (existing ground), about 3,5()O feet from the town proper.
A penstock would run from the intake structure of the dar.! to a~ ;
aboveground pO'-lerhouse, \'1hich would be located across the stream from the
village's Bureau of Indian Affairs school.
3
An open channel tailrace approximately 50 feet in length would be
excavated from the powerhouse to the main stream channel. Several
alternatives for the installation of the penstock and for the type of
pipe are p.resented here.
A dam with'a maximum height of 9 feet \'Iould be constructed from
standard manufactured galvanized steel gabions filled with rocks take'n
from the reservoir excavation and the stream itself. A sackcrete or
membrane cut-off wall extending to bedrock would be constructed at the
center of the dam. Thi s cut-off \'loul d extend approximately 9 feet below
the existimg ground surface; its top \'Iouldbe flush with the top of the
dam at elevation 600. The dam would extend about 50 feet across the
stream gully and \'IOuld include a spillway with a l3.S":foot-long weir, 2
feet lower than the top of the dam.
T\-~o alternatives were studied for the installation of the
l2-inch-di.aMeter penstock. For both alternatives, the invert of the
penstock at the intake structure is set at elevation S89, 11 feet below
the top of dam at elevation 600. A sluice gate would be installed to
regul ate the flow through the penstock and for emergency. operati on. The
penstock ",ould run downstream at an average slope of 13.5 percent. Under
the propol!ied plan" the penstock \'1ould be entirely buried about 2 feet
helo\'l the existing grade •. A trench \'IOuld be' excavated and backfilled as
requi red. The penstock would be anchored and supported as required. A
steel penstock was found to be more suitable than other materials ,for
installation because it is more durable against natural diaster or
vandalism., The penstock would cross the stream at a location
approximately 550 feet do\'mstream of the dam. .. . ,
The 'penstock would connect to a valve upstream of the ,turbine. The
powerhouse would be located at elevation 110 and be built on a concrete
slab. The finished floor elevation of the slab ",ould be about 4 feet
above the mainstream \'Iater level. Three different sites for the
powerhouse~ were considered,butgeological findings proved that two of
the sites were not suitable d~e to potential flooding and unsuitable s'oil
conditions,~ The equipment would be hOlJsed in a small 10xll-foot
structure.
The project power would be transmitted·through the existing local
distribution system. One or blo \'Iooden poles may be required for the
connection,~ No clearing of any vegetation would be necessary.
ENVI RONr1ENTAL SETTI NG
The village of Scammon Bay is located on the Kun River, approximately
150 miles north\'Iest of Bethel: Al aska.
The areas to the north and east of the village are lowland tundra"
\'Ihich is typical of the Yukon-Kuskok\"Iim Delta, with numerous lakes, slbw
r.reandering.. strear.rs, and little relief. To the west is ScalT.lon Bay and
the Bering Sea. IMmediately south of the village are the Askinuk
r10untains, a small isolated range that is an atypical feature of the
delta.
4
•
Beginning at Cape Ro~anzof on the B~rfng Sea, the mountains generally run
east anc1\'/est, tenninating approximately 35 ~iles inland. The mountain
range averages 1 ess than 6 ~il e,s in \,/i dth. Several peaks south of the
village exceed·' ,000 feet in elevation.
~ t· . {.~
The 10\'11 and tundra area supports the vegetati:ve' types associ ated \..,ith
wet tundra, primari ly a sedge and cottongrass mat \'/i th a fe\.., \toody plants
\'1here the terrace rai ses them above standi ng water. The Aski nuk
r10untains·have tHO distinct vegetative types. tloist tundra, which·
extends from the foothi 11 s throughout the 10\ter porti on of the range,
supports unifom. stands of cottong,rass .tussocks, sedges, and dwarf
shrubs. ,Alpine tundra, found at. the higher elevations of the Askinuk .
f1ountians, supports, lm'l-grO\'/ing Mats of herbaceous and shrubby plants.
Although the mountain range is relatively steep, the vegetative mat,
combined ~tith pemafrost holds the \'/ater to make the slopes Moist during
the nonfrozen season.
Habitats of the project area are predominate.ly r:lOist tundra. The
only dry areas are rock outcrops and individual boulders. 14ildlife
resources are ~ainly birds and small rodents with only a rare visit of
larger manmals. Because of the lack of shelter and year-round food
sources, the "/estern Yukon-Kuskohiim Delta is almost devoid of large
nan~al s. .
f'any species of birds use the area near the project. Nesting
\'/aterfO\',l and shore birds are abundant north of the village in the \-/et
tllndra habitat. They contri bute to the Yukon-Kuskokwirn Del ta IS 1. 5
million breeding ducks per year and fall migration of about 3 million
ducks. The moist and alpine tundra'areas south of the village in the
AskinlJk.11ountains support nesting and rearing habitats for an abundance
of shore birds. Although no actual population estimates \'1ere made, '
visual observations indicate that this is a favorable bird-use
environnent. An active rough-legged ha\'/k nest\tas located at the top of
the nountains directly south of the village. SnO\'{y o\,/ls and long-tailed
jaegers al so use the' area for hunti ng small nanmals and bi rds. .
An unnamed stream originates near the Askinuk'f1ountain range summit
and is fed by suhsurface flow throughout its length. The stream has
oenetrated the permafrost and formed a relatively wide streambed
channel. The rise in streambed elevation is very steep and thestream'is
mostly a conti nuous torrent of cascadi ng \'later. In several pl aces, the
strean has cut to bedrock, but 8 to 10 feet of unconsolidated material
i ntermi xed \Ii th boul ders is present at the proposed da~si te and 15 to 20
feet of the sane material is present at the pO\terholJse site. The' portion
of the strea~ from its source to near· the. village has avery stable'
stream channel. considering the steep slope ,and resultant high water
velocity. No areas of streambank eros;'on are evident and theamollnt of
fi ne s obse rved i n the st reamhed appea r . 10\,1 .
Historically, the strea~ supported' a 'very small run of ,p'ink salmon
near its nouth \'/here it eopties into the Kun River. Several small
\'/aterfall s, and one over 6 feet, el ir.1i nate any movement of fi sh fro~ the
Kun rtiver in front of the village into the upper section of the unnamed
strean. Even if no Haterfa11 s were present, the stream velocity is such
that suitahle fish habitat is generally nonexistant above the village.
5
The pink salmon run no longer exists in the stream and, according to the
Alaska Department of Fish and Game, no salmon now enter the Kun River.
The portion of the stream from the village to the Kun River is a
meandering tidal slough. The lm'ler end of the stream is used as a
protective mooring and beaching area for small skiffs.
The stream is used by the village residents as their drinking water
source. The Public Health Service established an infiltration gallery,
holding tank, and pumphouse far the \'/ater supply system. The
infiltration ga.llery is located several .hundr.-ed yards upstream of the
town and ,-/Ould be beb/een the dam and pm'lerhouse site of the proposed
project. The Public Health Service has recommended a minimum flow of
27.8 gallons per minute, which is~quivalent to 0.06 cfs. This \"ould·
provide approximately 200 gallons 'per day per capita, uhich is well above
the present consur.1ption of bet\'leen 50-70 gallons per day per capita. The
holding tank stores approximately 30,nOO gallons, which is sufficient to
supply the vi 11 age water requi rements for 2 days.
There is no approved Coastal Zone "anagement Plan for the ScamnonBay·
area. The Alaska Coastal Policy Councils Standards of the Alaska Coastal
r1anagement Program (6AA80. 070) establ.i shes criteri a for energy facilities
within the coastal zone. The proposed hydroelectric project is
consistant \<lith the suitable site determination outlined by the standards.·
CULTURAL hESOURCES
In earlier times, the village located at ScamMon Ray "las known by the
Eskimo name "r1ariak.1I The village \'las later renamed after the nearby bay
that honors Captain Charles r1. Scammon, \Iho served \'lith the t4estern
Telegraph Expedition from 1856-1967. The name Scammon Bay became
commonly applied to the village in 1951 \'/hen a post office of that name.
was estabished. Other names that have been applied to this locality are
Kutmi lit, r'awagni ut, "ari akmi ut, and r1a ri a~. The name Kutmi ut was fi rst
nentioned by Dal1 in 1870 for an Eskimo village located 2.7 miles east of
the present vi 11 age (Orth 1967).
The people in this area are of the rlagemiut subdivision or tribe :of
Yupik-speaking Eskinos. The r1agemiut numbered around 400 people at the
time of Eurnpean contact (Os\'/al t 1968: 0) and were essenti ally an i nl and
oriented people centered bet\'Ieen the Yukon and Kuskokwim River about 20
miles sOll~h of r10untain Village (Os\'/alt 1967:6, Zagoskin 1967:210.)
The r1agemiut "/ere noted· for their war-like behavior. This factor,
conbi ned "i th thei r renote 1 ocati on, meant that the '1ager.1i ut \'1ere not
exposed to i ntensi ve European/Allleri can contact unti 1 recent years. Fe\-I
:ethnographic stUdies have been done on the area so it is difficult to
reconstruct abori gi nal subsi stence patterns. Present day vi 11 agers are
involved uith connericial fishing for salmon and herring; it is likely
that these \'/ere harvested in the past along with inland resources such as
caribou and \'Iaterfo\'ll.
6
i
•
•
Good archeological sequences have been ''Iorked out for ,coastal areas
north of Norton, Sound and south of Brtstol Ray, but feN studies have been
done for the Yukon-Kuskoh/im Delta area. The National Register of '
Historic Places 'has, been consulted and no eligible properties are in or
near the 'project area."Phe'~State Historic Presenvation Office advised,
that no adverse inpacts "/ould he likely 'to:occur to cultural resources as
a result 'of thi s project.i
PfW,1ECT Ir1PACTS
Kydroelectric (Selected Alternativ~)
Background information and field investigations performed for the
hydroelectric 'alternative indicate that little fiSh and "iildlife activity
occurs \'Iithin the influence of the project area. There are no fishery
resources in the unnaned stream \'lith the possible exception of the area
north of the village near the Kun River. A rUn-of-river project, as the
one proposed for Scanr:1on Bay, does not , i flcl ude \'Iater storage . All 'or a
portion of the existing streamflml above the proposed div.ersionstructure
"/oul d be tltil i zed for pm'ler generati on and the "later \'Ioul d be returned to
the strean above the area of possible fishery activity without'changes in
",ater chen; stry, tenperature, or flO\'1 .. The stream het\'leen the proposed
di versi on structure and pO\'Ierhouse "/oul d lose sone or most of the flO\'I.
The porti on of the stream bet\'feenthe pOHerhouse and divers; on structure
is above several velocity barriers and waterfalls that inhibit fish
nigration. Because of the existing stream velocity in the area, suitable
fish habitat is generally absent'. , The proposed hydroelectric project
would have insignificant impacts on usable stream habitat and possible
fishery resources. The placenent of the 'diversion structure, penstock
alinenent, and tailrace configuration \'/Quld cause a' ter:1porary increase in
suspended sol ids; hm'lever, thi s r:1ay bemi nor and short terned because of
the 1 i ght load of fi nes and other snall-gra; ned nateri a 1. To assure that
the drinking \later standards for the village's ''later supply are r:1et;
construction of the diversion structu're and penstock nay have to occ.ur in
stages~ Close coordination ",iththe Public Health Service to determine
that acceptable drinking \-/ater can be stored and distributed would be
continuolJs until project completion.
~1i nor disrupti on of nesti ng and rear; n9 of 'shorebi rds nay occur
during project constructi.on if the activity is during the sur,wner months.
Although nesting densities are high in the Scammon Bay area, hird
utilization in the' area of project influence is lm'/. Haterfowl nesting
north of the village, shorebird activity in the noistand alpine tundra,
and pasteri ne bi rd nesti ng \-fest of the vi 11 age are far enough removed and
the nagnitude of the proposed action is sMall enough so that only minor
di sruptions are expected duri n9 constructi on. Ouri ngactual project'
operation, the disruption to the bird population should be ninimal or
nonexi stent.
r1ar:1nal activity in the project area is extrer:1ely low, possihly \'1ith
the exception of lenmings and voles. The magnitude of the project ,.,ould
cause only short-tern l'1i nor di sturbances of mamal s.
7
Constructi on of the reservoi r \'Ioul d requi re the excavation of
approxiMately 170 cubic yards (cy) of materi al. The area of excavation
\-Iould be \-lithin the streambed. The"majority of this material \'Iould b~,
used for t,he constructi on of the dan and an additional 30 cy of rock.
nateri al" from the surroundi ng area would be necessary for the cOMplet.i,on
of the structure. There is enough surface rock. material close to the'
proposed diversion dam so that a quarry site \'Iould not be required. "Fhe
excavation of the Materi'al for the reservoir and the collection of'
surface rock for the completion of the dan \10uld occur in an area of.
little biQ1ogica1 producti,vity and no impacts on the biological community
or' physical danage to the envi ronment are expected.
Penstock 'alineMent \fould occur within the streaM channel in an area
not underl:ai n with permafrost. If the buried penstock. alternative is
constructed, approxiMately 3,950 cy of naterial \'/ould be excavated. The
penstock "/ould be placed in the excavated area and all the material \'/ould
be backfilled. Thi s operation \",ould cause short-te'm adverse impacts to
water qual,ity; hO\,/ever, the stream should return to preproject conditi,ons
shortly after construct; on.
The pl'acenent of the powerhouse is outside the 1 DO-year flood pl aiin
in a suitable foundation area. Inpacts associated ''lith excavation for a
1 Oxl 1 -foot .concrete sl ah and pO\'/erhouse are mi ninal. Interti e with the
existing po\'Ier facilities',may require the placement of one wooden pole in
an area that has been di sturbed'.
The greatest inpact of project construction could be erosion caused by
mechanized equipnent on the steep slopes. Geological surveysindicat~
that pemafrost is present on all slopes withi n the project area with the
exception of the stream channel and flood plain. Removal of the thin .
vegetative mat could alloH pemafrost to tha\'I, resulting in ground
subsidence and subsequent creation of deep gullies from erosion. Damage
caused by tracked vehicles operating on tundra underlain. bypernafrost
has been \'Iell documented. The construction of the diversion structure,
penstock alineMent, and pO\'Ierhouse facilities, and the transportation':of
materials Hould require the use of a small-tracked vehicle that could'
avoid erosion~prone permafrost areas.
Normally, vehicular r:lovement is, not recor.,mended in strean channel?
hecause of water quality degradation and its effect on fishery
resources. HO\1eVer, the stream channel is of sufficient width to allo\"l
the opera:tion of a SMall-tracked vehicle with little or no instrean
novement and still avoid pennafrost areas. Water qual ity degradation;
\'Iou1 d be ni nor and no ir.lpacts are expected to the poss; bl e fi shery
resources" at the mouth of the stream. If project construction cor.wnences
,during the uinter nonths, naterials and equipment could be ferried \1hen
the ground is snO\'/ covered without di sturbi ng the vegetative nat. Pl ~ns
for \/; nter and sunner Mobil; zat;'on have been fornul ated and are i ncl uded
"in Section T. 9 of the nain report.
8
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.. :' ..... • ... ·4 .... ',· _',
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WINO GENEnATION
Although the Corps of Engineers has not designed any plans for the
wind generation alternative, the facility '-/ould probably be located
to\'1ard the top of the nountain range several miles south of the village.
The major impact associated \'Iith the construction of \'1ind generation
would be erosion. In order;. to service the ''Ii lid Ro\'/er facil iti es and
install the pO\'ier pol es, a road ''1oul d probably be requi red. The
construction of a road or even a It jeep trail It over areas underlain '-lith
pernafrost \'1ould cause serious erosion. Permafrost limits the rooting
depths of plants, prevents infilt~at;on of water dO\lnward through
surfici al mater; al s, and so increases surface runoff. Surface \'Iater
accumul ates in depressi ons ,-,here peaty materi al s forn, creati ng a
continuously I!/et environment conducive to marsh and tundra development.
The vegetative blanket insulates the pernafrost layer, increasing its
freezing depth. Disruption of the vegetative cover destroys the fragile'
thernal balance, resulting in tha\'/, subsidence, and erosion. To
construct any type of road in the mOllnta; ns behi nd Scamon Bay without
callsing erosion, an insulating gravel pad ,,,ould be needed. Even if a
road \'lith this type of insulating factor were constructed, erosion along
the edges of the road sti 11 nay occur. The construction of \,/i nd .
generati on faci 1 i ti es anY\'1here but wi thi n the vi 11 age proper \'1oul d
probably cause irreversible adverse environmental impacts .
9
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APPENDIX A
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Execut~v~ Summary ~f
the Final Coordination Act Rkport
for the Scammon Bay Hydropowe.y Project
Introduction
The village of Scammon Bay is located in the Bering Sea, near the confluence
of the Run River wHh Scammon Bay, 140 miles northwest of Bethel, Alaska.
The purp'ose of the study was to investigate the potential for a small
hydropower project to reduce the village's dependence on currently used
diesel power generation. '
Project Description
Present project plans include a small diversion, a l2-inch-diameter
penstock, and a powerhouse capable of generating 150 killowatts of power.
Two alternatives for penstock installation are being examined. One
involves burying the entire penstock approximately 2 feet below the
existing grade; the other involves partially burying the pipe for about
100 feet near the dam, and supporting the remainder of the penstock on
p:lles above the ground, anchoring it as needed. Both alternatives will
cross the stream approximately 55.0 feet below the dam.
Biological Inventory
Vegetation in the area consists of mats of cottongrass, sedges, mountain
aven, moss campion, black oxytrope, arctic sandwort, and woody shrubs
such as willow and alder.
The most important wildlife resource in the Scammon Bay area is the
avifauna using the coastal lowlands. Black brant; emperor, Canada, and
white-fronted geese; whistling swan; greater scaup; pintail; oldsquaw;
American ,wigeon; green-winged teal; black scoter; common~ spectacled, and
-Steller's elders are common waterfowl in the area. Shorebirds include
bar-tailed godwit; semi-palmated and American golden plover; common .
snipe; whlmbrel; brlstle-thighed curlew; spotted, least, semi-palmated,
and western sandpiper; greater and lesser yello~legs; dunlin; long-billed
dowi tcher; sandhUl crane; loons; and grebes. Raptors sighted in the
project vicinity include rough-legged hawk, gyrfalcon, and snowy owl.
Seabirds such as pelagic cormorants, horned and tufted puffins nest in
the cliffs of Scammon Bay. Glaucous, mew, and Sabine's gulls and arctic
terns also occur in the coastal ar~a. Small game birds include rock and
willow' ptarmigan, spruce grouse, and ruffed grouse •
Big game species found occasionally in the project area include moose,
brown bear, wolf, wolverine,-and lynx. Small mammals present include
arctic fox, red fox. marten, mink, river Qtt~r, short":'tailed -weasel,
beaver, muskrat, porcupine" snowshoe ltare, arctic hare, red .squirrel,,_ and
arctic ground squirrel.
MarIne mammals occasIonally seen in Scammon Bay include bearded, harbor.
ribbon, ringed seals, walrus, beluga, and,minke whales.
Executive Summary Page 2
Fish found' in Scammon Bay waters include chum, chinook, coho, pink, and
s"ockeye salmon, in decreasing dtder of abundance. Pacific herring and!
several sp"ecies of smelt also utZilize Scammon Bay. Several shellfish
species, including king crab, tanner crab, and several species of shrimp,
are present in the marine waters. Freshwater fish in the area include
northern pike, burbot, Dolly Varden, and wh1tefish.
There are no fish in the project stream above the village; due to the
streamvelioclty, suitaole fish habltat is absent. Several velocity
chutes prevent fish species" in the Kun River and Scammon Bay from"
ascending the stream.
Major Potential Impacts
Potential adverse impacts on fish and wildlife resources associated with
a small hydro on the stream running through Scammon Bay should be insigni-
f.lcant. The greatest impact of the project could be erosion caused by
mechanized equipment moving on the steep slopes. Removal of the thin
vegetation layer could allow permafrost to thaw, resulting in ground
subsidence ahd subsequent cteation of deep gullies from erosion.
There are no fish in thestrea.m a.bove the village and none of the project
features should have any impact on the lower portion of the drainage or
the Kun River.
Discussiol\
The FWS has concluded that few adverse impacts of fish and wildlife
resources from the project are anticipated. Those that may occur are
.judged to be inperceptable provided that methods to minimize erosion are
implemented. "
Construct1lon of the diverslonwill require excavating material and wUl
necessitat"e the use of a tracked vehicle with a blade or "bucket. Because
nO access road is a.vailable fOl: transportion of the equipment site, w~
recommend that the diversion be built "after the tundra has frozen in 'the
fall. Impacts from tracked .vehicles are considerably less when the
ground" is frozen. Where "the diversion is built, some type of protective
mat should be placed over eXposed soil to prevent erosion and the arejl
seeded wi'th grass at the beginning of the hext growing season.
If the eE decides not to "construct the diversion when the tundra is
"frozen, a!!cess to the diversion site becomes mOTe of a problem. In many
'plac'es, the high water stream channel (bank to bank) Is wide enough to
.allow a small "cat" to move up the drainge parallel to the stream avoiding
traversing the tundra or negotlating the steep banks adjacent to the
stream. "Through time, the stream has cut down to bedrOCk, or close ttl
it, and left a very stable subStrate of rock and small boulders capab,le
Of wlthstanding the weight of a small "cat" without damaging the stream
channel o'r stream banks. Ai though moving equlpplent close to a stream is
ncH: normally recommended. In this instance it would be preferable to
cons truct'lon a of "road" on the tundra.
For reasons previously stated concerning permafrost, we recommend tha"t
the penstock be elevated and not buried. Furthermore,there appears ;to
" "be adequate room and suitable foundation support in the thaw zone along
·the stream. Placement of the penstock parallel to the stream will ~ke
"t t unnece"ssary to lay pipe and foundation supports on the tundra.
!"
Executive Summary Page 3
Penstock pipe and other equipment capable of being easily transported by
heHcopter should be flown to the area and not moved by heavy equipment.
If it .is necessary to level:'an area for the po~e·thouse, we recommend it
also be done when the tundra Is frozen, and a thick protective gravel pad
be placed over the exposed soil to provide insulation.
In all instances, any fuel, oil, or lubricants should be stored and
handled in such a manner so as to preclude their entering any water-
course.
Recommendations
The following recommendations are provided to minimize the potential
environmental impacts of constructing a small hydro project at Scammon
Bay:
1. That the use of tracked vehicles to construct the diversion
take place when the tundra Is frozen;
2. that the movement of tracked vehicles used to construct the
diversion be restricted to closely paralleling the rocky
streambed should the diversion be built when the tundra has
thawed;
3. that the CE coordinate all activities in or near the stream
with the appropriate governmental agency responsible for the
Scammon Bay water supply system;
4. that all areas of exposed soil be covered with a protective mat
material or other suitable means and seeded with grasses at the
beginning of the next growing season to prevent surface erosion;
.
5. that the penstock be elevated and closely parallel the existing
stream channel;
6. that penstock pipe and other equipment easily transported.by
helicopter be flown to the construction site and not moved by
heavy equIpment;
7.
8.
that any leveling for the powerhouse si.te be done when th~
tundra is frozen, and a thick gravel pad be placed over the
exposed area to provide an insulation layer; and
that any fuel, oil, or lubricants be stored and handled in such
a manner to insure they do not enter any watercourse.