HomeMy WebLinkAboutBradley Lake Winter Flow Conditions for Salmon Egg Incubition 1995BRADLEY LAKE HYDROELECI'RIC PROJECf
INVESTIGATION OF WINTER FLOW CONDITIONS REQUIRED TO SUPPORT
SALMON EGG INCUBATION
FINAL REPORT
Prepared by
John W. Morsell
N orthem Ecological Services
~chorage, AJaska
Prepared for
AJaska Energy Authority
~chorage, AJaska
December, 1995
INTRODUcriON
The Alaska Energy Authority is investigating various methods for measuring the adequacy
of flow in the lower Bradley River during winter conditions. Minimum flows to maintain
fish resources, as required by the Bradley Lake Hydroelectric Project license, have been
measured at a gaging station near Tree Bar Reach (Figure 1). The amount of water to be
released from the dam into the river is normally determined by the Tree Bar Reach gage
measurement. However, in recent years ice cover during portions of the winter has altered
the channel configuration at the gage site and caused the gage readings to give an
inaccurate flow determination. During periods of ice cover, project managers have been
required to release the entire minimum flow into the river at the dam to assure downstream
compliance even though additional water is contributed by other portions of the watershed.
This procedure is wasteful of water which would otherwise be available for energy
production.
It was suggested that a closer look at the impact of various flow levels and ice conditions
on the physical characteristics of the stream during the winter might be appropriate to help
resolve these difficulties in flow measurement with special emphasis on the habitat
requirements of incubating salmon eggs and alevins (newly hatched fry). Such information
might allow different methods of protecting fish habitat to be examined which would be
based on objective criteria and eliminate waste.
A study of winter flow conditions as they relate to the requirements of incubating salmon
eggs was initiated in 1993 and continued through 1995. This cooperative study involved
primary data collection by the U.S. Geological Survey (USGS) with interpretation regarding
fish habitats by Northern Ecological Services. An annual progress report relative to
fisheries aspects of the winter minimum flow study program was prepared in December,
1994 which summarized results through 1994. The current document provides an update
to the 1994 report by analyzing hydrological information collected during the winter of
1994-1995, and provides a final summary discussion relative to project objectives utilizing
information collected during the 1993-1995 period. This report represents the final input
1
to the effort from Northern Ecological Services. The USGS will continue to collect basic
winter hydrologic information through 1998.
It should be emphasized that USGS policy requires that all data collected by the agency be
considered provisional until subject to in-bouse quality control and publication in an official
USGS publication. Hydrological data reported herein should be viewed as preliminary.
STUDY OBJECfiVES
1. To gain insight into the relationship of low winter flows to the physical habitat
requirements of incubating salmon eggs with emphasis on ice cover conditions.
2. To determine whether an alternative method of measuring habitat protection,
such as stage measurement or minimum dam releases, would allow adequate
protection.
3. To determine whether a reduced flow requirement might also provide adequate
protection.
4. To gain insight into the lower limit of flow that would provide some assurance
of egg survival in the event of unexpected decreases in flow.
BACKGROUND INFORMATION
During the spawning process, salmon eggs are deposited in a depression excavated in the
stream bottom. The spawning fish then cover the eggs by pushing gravel into the
depression. Incubating salmon eggs are generally buried to a depth of 15-45 em within the
stream bottom gravel. The interchange of water between the stream surface flow and the
subsurface gravel environment is crucial to the survival of salmon eggs, providing oxygen
to the eggs and carrying away .toxic metabolic products. Factors that control the water
interchange between stream and gravel bed are: stream surface profile (including water
2
depth and velocity), gravel permeability, gravel bed depth, and irregularity of the stream
bed surface (Reiser and Bjo~ 1979). The most important hydraulic component of the
intragravel environment is the apparent velocity -velocity of water moving through the
gravel. This velocity is a function of the hydraulic head (depth of water above the gravel)
and the permeability of the gravel. If the apparent velocity is too slow then oxygen can
become depleted due to oxygen demand from decaying organic matter in the gravel, and
waste products from developing embryos or alevins can build up reaching toxic levels. It
is not practical to measure apparent velocity under field conditions. However, other
parameters such as wetted perimeter, water depth, velocity, and intragravel oxygen
concentration can provide an indication whether the intragravel environment is suitable for
incubation.
Many studies have established suitability criteria for salmon spawning habitats but few have
specifically addressed incubation habitats within ice covered streams. During the instream
flow study conducted for the Bradley River prior to project licensing, spawning habitats
were reduced to "effective spawning habitat" by applying incubation criteria (Woodward-
Clyde Consultants, 1983). Habitats were considered unsuitable for incubation {and thus
unsuitable for spawning) when depth was 0 ft. or velocity was less than 0.1 fps. At
velocities between 0.5 and 0.1 fps, incubation suitability decreased because of the potential
for silt deposition. Reiser and White (1981) suggested that a depth of greater than 6 inches
and a stream flow velocity of greater than 1 ft./sec. is usually adequate to assure incubation
success and prevent freezing of gravels. These guidelines assume that gravel permeability
is sufficiently high to allow reasonable circulation. Stream bed composition (especially the
proportion of fine materials) and permeability are important variables that are beyond the
scope of this study program.
Salmon streams in Alaska are subject to various climatic extremes and developing salmon
eggs are often able to withstand adverse conditions for varying periods of time. Incubating
eggs within a gravel redd can withstand dewatering for up to several weeks provided that
the intragravel environment remains moist and does not freeze (Reiser and White, 1981).
Reduced flow and reduced dissolved oxygen concentrations (as low as 5 mg/1) can also be
3
tolerated for substantial periods of time. Suboptimal but non-lethal oxygen conditions
usually result in slower development rates and reduced fry size rather than drastically
reduced survival (Reiser and Bjornn, 1979). Freezing (formation of ice crystals within eggs
or alevins) is usually fatal.
Ice conditions on the Bradley River are highly variable. The southern Kenai Peninsula
experiences changeable winter weather with freezing periods often broken by periods of
above freezing temperatures. In addition, extreme tidal fluctuations cause water levels to
rise and fall within much of the study area. This combination of conditions causes ice cover
to break up and reform several times in the average winter. Also, under conditions of
extreme cold, anchor ice Can form on the stream bottom and reduce the exchange of water
between the surface and intragravel environments. Anchor ice is usually a temporary
condition.
METHODS
Study Sites
The portion of the Bradley River utilized by spawning salmon has been well identified
through studies of salmon escapement that have been conducted by the Alaska Energy
Authority since 1985. Six transects were selected within this area that correspond to known
pink salmon spawning areas (Figure 1). Survey techniques were utilized to establish vertical
and horizontal controls within and between each stream cross section. The control survey
was conducted on June 29, 1993.
Data Collection
The study plan requires that wetted perimeter, depth profile, stream-water velocity profile,
and discharge be collected three times each winter at each transect beginning in late winter,
1993. Hydrological data collection procedures followed USGS protocol and methods will
be detailed in the appropriate USGS data reports. During the period from November 1994
4
through April 1995, four field investigations were conducted: November 30-December 1,
1994; January 11-12, 1995; February 28-March 1, 1995; and April 4-5, 1995. Additional
information collected at each transect included water temperature, specific conductance,
surface water dissolved oxygen concentration, and intragravel dissolved oxygen. Ice
conditions and ice impacts on channel configuration were noted and photographs were
taken of each section.
Water for intragravel DO measurement was collected by driving a custom fabricated
stainless steel tube about 30 em into the gravel. The end of the tube was perforated to
allow water intake. Water was slowly pumped from the tube into DO sample bottles using
a peristaltic pump. Dissolved oxygen concentrations were determined using standard
chemical fixation and titration methods.
RESULTS
Results of the winter 1994-1995 field investigations are summarized in Tables 1 and 2.
Table 1 presents selected hydraulic parameters for the 6 transect sites and Table 2 presents
selected discharge and water quality information. Cross sections and velocity profiles for
each date and transect are presented in Figures A through F. No cross section
measurements were obtained at the Tidewater or Tree Bar Reach transects during the
January survey because of deep water and unsafe wading conditions.
A variety of conditions were observed in 1994-1995. During the November 30-December
1 survey, ice cover was complete and under ice flow conditions were stable. The January
survey occurred during a period of rapidly forming ice following a thaw, resulting in variable
ice cover and irregular flow patterns. During the March survey, ice cover ranged from 30
to 100 percent and was in the process of breaking up. The April survey occurred during
open flow with ice only along the edges.
5
DISCUSSION OF WINTER 1994-95 RESULTS
Hydraulic Conditions
Discharge measurements during the 1994-1995 studies (Table 1) ranged from about 45 cfs
to 63 cfs with most measurements in the 50-55 cfs range. The flows, while 20-30 percent
above the required minimum, were lower than those encountered during the winter of
1993-1994 and, thus, were more representative of the winter minimum flow condition.
It is instructive to compare the cross sections for each transect at the different survey times.
The April survey was conducted during a period of nearly open flow, consequently the
surface water elevation, wetted perimeter, and velocity profile is more or less indicative of
"normal" conditions thus providing a useful baseline.
Under the total ice cover conditions present during the November 30-December 1 survey
period, most transects appeared to be characterized by higher water surface elevation and
somewhat slower velocity than would occur under open flow conditions. Wetted perimeters
were similar to open flow at most transects. A significant anomaly occurred at Tree Bar
Reach (Figure C) where water surface was about 2ft. above normal and grounded ice in
the middle of the stream split the channel in two causing zero velocity over part of the
stream bottom.
The conditions observed during the January survey were the most extreme of any seen
during the three years of the study program. A long period of unusually warm weather had
been followed by several days of extreme cold weather. Ice was forming rapidly causing
anchor ice formation, irregular ice cover and flow patterns, water backup, and overflow.
Although measurements could not be made at the Tree Bar and Tidewater sections, water
surface elevation was about 2 ft. above normal, wetted perimeter was greater than open
flow, and velocities were probably somewhat slower than normal. Higher then normal
water surface elevation and water depth was seen at all sections suggesting that backup of
water was caused by an ice dam downstream from the study area and, possibly, channel
6
constriction. Mean velocity was substantially lower at all measured sections (Table 1 ), in
some cases less than half of the open flow value. In most cases wetted perimeter was
increased.
Conditions observed during the February 28-March 1 survey period included ice cover
ranging from 30-100 percent with mild air temperature and some ice breakup occurring at
the time of the investigation. Cross sections and velocity profiles were similar to those seen
under open flow conditions at all transects.
During the April survey little ice was present except for shelf remnants at the channel
edges. Conditions were essentially open flow and cross sections were similar to those
observed during the 1993 baseline survey. Some minor changes in channel geometry
compared to the June 1993 survey were evident.
Water Quality
Dissolved oxygen concentrations for surface water samples (Table 2) were all essentially
saturated as would be expected for waters in a shallow turbulent stream. Intragravel DO
concentrations at all transect locations were somewhat lower than the surface water values.
These small differences were likely caused by slightly higher water temperature and lack
of supersaturation within the gravel; a small amount of oxygen demand within the sediment
might have also contributed to the lower concentration. Dissolved oxygen concentrations
in the 10-14 ppm range are normal for cold intragravel environments and are more than
adequate for egg incubation. The minor depression in DO would not be expected to affect
survival, but could have a small effect on the growth rate of embryos and alevins (Reiser
and Bjornn, 1979). There was no obvious relationship between oxygen concentration and
either depth or velocity of water at the intragravel sampling sites (Table 2).
Conductivity (specific conductance) was low and relatively uniform between sites. Some
concern has been expressed that saline water from Kachemak Bay could enter the Bradley
River during high tidal periods and affect the areas where salmon eggs are incubating. The
7
conductivity measurements showed no indication of salinity effects.
Salmon Study Program vs. Wmter Survival
Numbers of adult salmon utilizing the Bradley River have been estimated since 1986
including five years under the regulated flow regime. Pink salmon, the primary evaluation
species, have a two year life cycle; consequently, adults returning in 1993, 1994, and 1995
were the result of eggs spawned during operational flows. Survival from egg to adult in all
the above years appeared to be favorable. While there are many factors that affect
escapement numbers, the favorable returns suggest that survival of incubating eggs was
good. If fish production is considered to be the ultimate measure of the success of the fish
water bypass system, then information to date indicates that the system is successful. There
is no indication that the existing flow regime has created problems for the fish.
SUMMARY CONCLUSIONS
Wmter Flow vs. Salmon Incubation Habitat
During the course of the study, intragravel dissolved oxygen concentrations were measured
from six spawning ground transects under a wide variety of winter conditions. At all times
the intragravel environment appeared suitable for salmon egg incubation with no indication
of marginal conditions. Problems related to sedimentation or low intragravel velocity often
seen on other streams were apparently not a factor in the Bradley River study area. It
appears likely that the most significant danger to salmon eggs or alevins in the Bradley
River is freezing. Since surface and intragravel water temperatures remain near 0 degrees
C. throughout much of the winter, freezing could occur rapidly if intragravel flow were
greatly reduced or cut off. Loss of intragravel flow within spawning areas could occur if
wetted perimeter was significantly reduced or if flowing water was diverted away from a
stream area where incubating eggs were present. Protection of salmon incubation habitats
should emphasize protection from freezing by assuring the presence of flowing water within
spawning habitats.
8
Flow Measurement Alternatives
As described in the Introduction, monitoring the stream flow in the Lower Bradley River
to assure compliance with minimum flow requirements has not been consistently accurate
in the winter. Ice conditions in the Lower Bradley River within the fish use area are highly
variable within a given year and between years. Under some conditions ice effects can
cause significant changes to channel geometry and hydraulics. The greatest changes
occurred when extreme cold air temperatures were combined with open flow conditions,
causing rapid cooling and ice formation. Such conditions most commonly caused backing
up of water at some locations resulting in increased depth and reduced water velocity
sometimes accompanied by increased wetted perimeter. Temporary channel constriction
due to grounded ice or edge ice formation also occurred under some circumstances.
Complete ice cover for an extended period combined with moderate weather conditions
usually allowed the flowing water under the ice to eventually resume a configuration similar
to open flow. Anomalous flow conditions were usually temporary lasting less than two
weeks. While some patterns were noted in the ice and channel conditions, there was a
definite element of unpredictability regarding the timing and exact nature of hydraulic
changes.
Because of this lack of predictability, measurement of stream flow within the Lower Bradley
River channel in the winter using a stage recording device or other specialized method is
not realistic. Establishing a minimum flow release at the dam is considered to be a more
realistic and reliable means of assuring adequate downstream flow.
Reduced Minimum Flow
A reduction in the minimum flow requirement would allow more water to be available for
power generation and, thus, is attractive to project operators. The Bradley River instream
flow study completed prior to licensing (Woodward-Clyde, 1983) modelled the effective
spawning area (based on incubation criteria) and found little difference in useable area
9
between minimum flows of 30, 40, or 50 cfs. While stream geometry has changed somewhat
since the Woodward-Oyde study, it is likely that the same relationships hold under existing
conditions. The Woodward-Oyde stream model suggests that minimum winter flow could
be reduced somewhat from the existing 40 cfs requirement without significantly reducing
wetted perimeter or velocity.
Stream flows during the current study have been consistently well above the required
minimums; consequently, little additional insight has been acquired regarding actual winter
conditions during exceptionally low flows. The observations do indicate that conditions on
the spawning areas under widely varying winter conditions were adequate for salmon
incubation based on dissolved oxygen, depth and velocity criteria No marginal conditions
were noted suggesting that flow could have been reduced somewhat without significantly
affecting survival of eggs or alevins.
One approach to developing a recommendation for a new minimum flow would be to
construct a model of the hydraulic conditions at the six spawning area transects under
varying discharge. The model would allow prediction of essential stream characteristics
(wetted perimeter, depth, and velocity) at different flow levels. Applying incubation
suitability criteria to the model would allow the selection of a minimum flow suitable for
fish habitat. The difficulty arises in defining suitability criteria such as minimum acceptable
depth or velocity; at this time there are no objective data that relate actual stream
conditions to egg survival and development.
Lower Limit of Flow
Defining a short term or "crisis" low flow limit that would allow survival of incubating eggs
under all conditions is probably not possible because of the large number of variables.
Salmon eggs can withstand complete dewatering for periods of hours or days as long as the
intragravel environment remains moist and does not freeze. However, on the Bradley River
during periods of no insulating ice cover and very cold air temperatures, loss of flow would
likely cause extensive freezing of stream bed gravels and loss of eggs. Therefore, flow
10
reduction to near zero would not be acceptable for any length of time. Flow reduction to
the point where wetted perimeter would be significantly reduced would also not be
acceptable since incubating eggs at the stream margins would likely freeze.
Again, by using hydraulic models it might be possible to suggest minimum "crisis" flow
providing that criteria could be agreed upon. For example, flow that maintains 80 percent
of "normal" wetted perimeter and a minimum depth of 4 inches at channel center might
be considered adequate in the short term.
RECOMMENDATIONS FOR FUTURE STUDY
The Alaska Energy Authority currently plans to continue the USGS effort to collect
hydrological data under winter conditions for an additional three years through 1998. This
information will provide continuing documentation of winter conditions and will be
especially valuable if winter flows are brought closer to required minimums. The USGS
should be encouraged to utilize the information to construct hydraulic models at each cross
section so that critical parameters can be predicted for varying discharge. It is
recommended that AEA hold an annual working session that includes representatives from
USGS, NES, Homer Electric, and Shannon & Wilson to discuss the information and
ultimately develop flow management recommendations for presentation to the regulatory
agencies.
REFERENCES
Bjornn, T.C. and D.W. Reiser, 1991. Habitat requirements of salmonids in streams. In:
Influences of Forest and Rangeland Management on Salmonid Fishes and their
Habitats, Am. Fish. Soc. Special Publ. 19, Bethesda, Maryland.
Reiser, D.W. and T.C. Bjornn, 1979. Habitat requirements of anadromous salmonids. USDA
Forest Service, General Tech. Report PNW-96, Pacific NW Forest and Range
Experiment Station, Portland, Oregon.
11
Reiser, D. W. and R.G. White, 1981. Influence of streamflow reductions on salmonid embryo
development and fry quality. Idaho Coop. Fish. Res. Unit, Res. Tech. Completion
Rep., Project A-058-IDA
Woodward-Clyde Consultants, 1983. Bradley River Instream Flow Studies. Prepared for the
Alaska Power Authority, Anchorage, Alaska.
12
-0-R-A-F-T-
Table 1. Selected hydraulic properties for the lower Bradley River, November 1994 -April 1995.
[ft. foot; ft 2, square foot; ft/s; foot per second; ft 3/s. cubic foot per second;<. less than;>, more than}
Transect site
(fig. 3)
Bear Island
Tidewater
Tree Bar
Reach
Below Fish
Camp
UpperRiffie
Reach
LowerRiffie
Reach
Date
12-01-94
01-11-95
03-01-95
04-05-95
12-01-94
01-12-95
03-01-95
04-05-95
11-30-94
01-12-95
02-28-95
04-04-95
ll-29-94
01-12-95
03-01-95
04-04-95
12-01-94
01-12-95
03-01-95
04-05-95
11-30-94
Ice cover Discharge
(percent) (ft 3/s)
100 45.5
80 62.7
30 53.0
<10 56.7
100 55.2
90 1
100 52.5
0 57.1
100 51.8
90 1
100 56.5
<10 55.3
100 48.4
100 42.6
100 47.5
<10 57.9
100 47.1
100 50.5
100 47.5
<15 56.9
100 46.8
Discharge
accuracy
(percent)
>8
8
8
5
>8
8
8
>8
8
5
>8
>8
>82
8
>8 2
>8
8
5
>8
Mean
velocity
(ft/s)
0.66
0.49
0.98
0.91
0.76
1.11
l.l3
1.19
0.97
1.24
0.67
0.34
0.79
0.81
0.72
0.33
0.81
0.70
1.00
Mean
depth Top width
(It) (ft)
0.80 93.0
1.22 lOS
0.67 81.0
0.72 85.8
1.74 41.5
1.25 38.0
1.26 40.0
0.93 59.0
0.84 69.0
0.65 69.0
1.22 59.7
1.95 64.0
0.98 61.0
1.23 58.0
0.79 77.6
1.43 116
0.69 84.5
1.00 82.0
0.55 84.0
Wetted Hydraulic
perimeter radius
(ft) (ft)
74.6 93.9 0.79
129 106 1.23
54.3 81.3 0.70
62.2 86.5 0.70
72.2 43.3 1.67
47.4 38.6 1.23
50.4 40.5 1.24
55.0 60.1 0.92
58.0 69.9 0.85
44.5 69.2 0.64
72.7 60.1 1.21
125 64.5 1.94
60.1 61.3 0.99
71.5 58.3 1.23
61.4 80.3 0.76
166 118 1.41
58.3 85.9 0.69
81.8 82.8 0.99
46.9 86.4 0.55
·D-R·A·F-T·
Table 1. Selected hydraulic properties for the lower Bradley River, November 1994 -April 1995.
[ft. foot; ft 2 • square foot; fl/s; foot per second; ft 3/s, cubic foot per second;<. less than;>, more than)
Discharge Mean Mean Wetted Hydraulic Transect site Ice cover Discharge velocity Top width Area
(fig. 3) Date (percent) (ft3/s) accuracy (ftls) depth (ft) {ft2) perimeter radius
{percent) (ft) (ft) (It)
01-12-95 100 61.4 8 0.42 1.69 86.0 145 88.7 1.63
03-0l-95 100 47.8 8 l.14 0.59 71.0 42.0 72.5 0.59
04-05-95 0 53.8 5 l.l4 0.57 82.0 47.0 82.3 0.57
1 Unable to measure all parameters because of thin ice and deep water.
2 Measurements may be tide affected.
--
·0-R-A-F·T·
Table 2. Selected water-quality data and site characteristics for the lower Bradley River, November 1994 • April 1995.
[mm Hg, millimeter of mercury; °C, degree Celsius; mg/L, milligram per liter; ~s/cm, microsiemens per centimeter; ft, foot; ft/s, foot per second; --no data]
Transect site
(fig. 3)
Bear Island
Tidewater
Tree Bar
Reach
Date
12.01-94
01-11-95
03.01-95
04.05-95
12-01-94
01-12-95
03-01-95
04.05-95
11-30-94
01-12-95
03-01-95
Baro-
metric
pressure
(mm Hg)
175
759
780
752
775
762
778
754
770
762
780
Temper-
ature
(OC)
0.0
0.0
0.5
1.0
0.0
0.0
0.0
1.0
0.0
0.0
0.0
Surlace water
Dissolved
oxygen
(mg'L)
14.8
14.4
14.4
14.1
14.8
14.3
14.4
14.0
14.7
14.8
14.4
Dissolved
oxygen
percent
saturation
100
99
98
100
100
98
96
99
99
101
96
Specific
conduct-
ance
(~s/cm)
70
75
62
64
69
68
62
74
69
62
Temper-
ature
(OC)
1.0
1.0
lntragravel water
Dissolved
oxygen
(mgll)
13.3
12.1
14.1
12.4
11.4
13.0
12.4
13.4
13.0
Dissolved
oxygen
percent
saturation
90
87
Depth of
water above
streambed at
intragravel
sample
location
(ft)
O.!D
O.!D
0.45
1.10
0.4
1.6
<1.2
Surlace-
water
velocity at
intragravel
sample
location
(IVs)
0.6
0.0
0.3
0.6
0.2
1.0
-0-R-A-F-T-
Table 2. Selected water-quality data and site characteristics for the lower Bradley River, November 1994 -April 1995. --Continued
[mm Hg, millimeter of mercwy; °C, degree Celsius; mg/L, milligram per liter; jls/cm, microsiemens per centimeter; ft, foot; ft/s, foot per second; --no data]
Surlace water lntragravel water Depth of Surface-
Baro-water above water
Transect site metric Dissolved Specific Dissolved streambed at velocity at
Date Temper-Dissolved Temper-Dissolved intragravel intragravel
(fig. 3) pressure oxygen conduct-oxygen
(mmHg) ature oxygen percent ature oxygen percent sample sample
(OC) (mgtl) a nee (OC) (mg/L) location location saturation (IJ.S/cm) saturation (It) (ft/s)
Tree Bar 04-05-95 754 1.5 13.9 99 63 1.5 12.5 89 0.% 1.2
Reach, con 't
Below Fish 12-01-94 774 0.0 15.0 101 70 --12.8 --0.4 0.6
Camp
01-12-95 762 0.0 14.8 101 69
03-01-95 781 0.0 14.5 97 62 --13.2 --0.4 0.5
04-05-95 754 l.O 14.0 100 ----12.5 --1.22 0.9
Upper Riffle 12-01-94 776 0.0 14.6 98 70 --!0.7 --OHl 0.4
Reach
01-12-95 762 0.0 14.7 101 71 --11.4 --QiU 0.2
03-01-95 782 0.0 14.2 95 64 --13.9 0.65 0.1
04-05-95 752 1.0 13.0 99 65 --12.2 --1.00 0.1
-D-R·A·F·T·
Table 2. Selected water-quality data and site characteristics for the lower Bradley River, November 1994 • April 1995. --Continued
[mm Hg, millimeter of mercury; °C, degree Celsius; mg/L. milligram per liter; ~/em, microsiemens per centimeter; ft. foot; ft/s, foot per second; --no data]
Surface water lntragravel water Depth of Surface-
Baro-water above water
Transect site metric Dissolved Specific Dissolved streambed at velocity at
Date Temper-Dissolved Temper-Dissolved intragravel intragravel (fig. 3) pressure oxygen conduct-oxygen ature oxygen ature oxygen sample sample (mmHg) percent ance percent (OC) (mg/L) saturation (J.Ls/cm)
(oC) (mg/L) saturation location location
(It) (ft/s)
Lower RifH'e ll-30-94 767 0.0 14.7 100 76 --10.1 --09) 1.2
Reach
01-12-95 762 0.0 14.5 99 71 --12.5 --OJ{) <0.6
03-01-95 782 0.0 14.4 96 64 --13.3 --0.15 0.5
04-05-95 752 1.0 13.8 98 64 .. 10.8 --<1.2 <2.0
:z:
PIGORB 1
0 300 Winter Study Transect
Locations.
Scale ill l'eet
20
1-:::E w:l WI-u..<( 16 i5:o
·>-Za; Qq:
1-G: <Ct: 16 >m Wa; uj<e
14
0 20 40 60
0 3 z
0
0 w
(/)
a: w 2 a..
1-w w u..
l!l:
~
8 -' w > 0
0 20 40
BRADLEY RIVER AT BEAR ISLAND
80
CROSS SECTION
100 120 140 160 180 200 240
DISTANCE FROM LEFT BANK, IN FEET
VELOCfTY PROFILE
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
December 1, 1994, 1 00% ice cover
Discharge, 45.5 cubic feet per second
180 200 240
DISTANCE FROM LEFT SANK, IN FEET
Date of survey, ice conditions, and discharge
December 1, 1994, 1 00% ice
Discharge 45.5 cubic feet per second
Figure A. Cross·section and velocity distribution of the tower Bradley River at Bear Island
20
1-::s w::J w,_
IJ..<( 16 ~0
">-Za: Q<e
1-0: <t: 16 >m Wa:
u:J<
14
0 20 40 60
BRADLEY RIVER AT BEAR ISLAND
CROSS SECTION
Water surface 17.011.
60 100 120 140 160 160 200 220 240
DISTANCE FROM LEFT BANK, IN FEET
VELOCITY PROFILE
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
January 11, 1995, 80% ice cover
Discharge = 62.7 cubic feet per second
~ 3 r-~--.-~r--.--~-.---r--.-~--.--.---.--r--.--~-.~-r--,--.---.--~~--~~
0 u w
(/)
a: If 2
1-w w
IJ..
~
~ g
~ 0 ~~--~--~~-A~~~~--~~--~~~~~~~--~~~~--~~--~--~~--~~
0
Figure A. Continued.
160 160 200 240
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
January 11, 1995, 80% ice cover
Discharge= 62.7 cubic feet per second
BRADLEY RIVER AT BEAR ISLAND
CROSS SECTION
14 ~~--~~~~--~~--~--~~--~~--~--~~--~~L-~--~~--~--~~--~~
0 20 40 60 eo 100 120 140 160 180 200 220 240
DISTANCE FROM LEFT BANK, IN FEET
VELOCITY PROFILE
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
March 1, 1995, 30 percent ice cover
Discharge, 53.3 cubic feet per second
~ 3 .-~--,-~---r--T-~--~--.--r--~~--.---r--r--~~---r--.-~--.---r--r--~~
0
0
UJ
(I)
ffi 2 0..
tu
UJ u.
~
~
9
~ oL-~--J-~~-L--~~--~--L-~--~~--~--~~--~~~~--~~--J---~-L--~~
0 20
Figure A. Continued.
140 160 160 200 220 240
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
March 1, 1995, 30 percent ice cover
Discharge, 53.3 cubic feet per second
BRADLEY RIVER AT BEAR ISLAND
CROSS SECTION
20
1-:::E w::J
WI-u.< 18 ~Cl
·>-Za: s~ <t:: 16 >m ~a: w<
14 ~~--~~---L--~~--~--~~--~~~-L--~~--~~~~--L-~--~--~~--~_J
0 20 40 60 eo 100 120 140 160 180 200 220 240
DISTANCE FROM LEFT BANK, IN FEET
VELOCITY PROFILE
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
April 5, 1995, minor shore ice
Discharge, 56.7 cubic feet per second
~ 3 r-~--~----~--~~--,---r-~--,-~.--.--~~--,-~.--.--~-.--,---r--.--~~
0
0 w
(/)
a:
If 2
1-w w u.
~
~
9
~ 0~~--~~---L----~~--~--~~--~--~-L~._~--~~~~--~~--~--~~--~~
0 20 40
Figure A. Continued.
160 160 220 240
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
April5, 1995, minor shore ice
Discharge, 56.7 cubic feet per second
BRADLEY RIVER NEAR TIDEWATER
CROSS SECTION
Water surface 15.6 rt.
14
12~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0 10 30 40 60 70 90 100 110
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions. and discharge
June 29, 1993, open-water baseline
December 1 , 1994, 1 00% ice cover
Discharge, 55.2 cubic feet per second
VELOCITY PROFILE
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
December 1 , 1994, 1 00% ice cover
Discharge, 55.2 cubic feet per second
Figure B. Cross section and velocity distribution of the lower Bradley River near Tidewater
1-:::!! w::l ll:~ ;:;o
~~ j::~ <t: >m Wa:
ul<
BRADLEY RIVER NEAR TIDEWATER
CROSS SECTION
20
18
16
14
12~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0 10 30
Figure B. Continued.
40 50 60 70 80 90 100 110
OIST ANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions. and discharge
June 29, 1993, open-water baseline
March 1 , 1995, 40 percent ice cover
Discharge, 52.5 cubic feet per second
VELOCITY PROFILE
OIST ANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
March 1, 1995, 40 percent ice cover
Discharge, 52.5 cubic feet per second
BRADLEY RIVER NEAR TIDEWATER
CROSS SECTION
20
Water surface 14.81 ft.
12~~~~~~~~~~~~~~~~-L~~~~~~~~~-L~~~~~~~~~~
0 10 30
Figure 8. Continued.
40 50 eo 70 80 100 110
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
AprilS, 199S, no ice
Discharge, S7.1 cubic feet per second
VELOCITY PROFILE
OIST ANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
AprilS, 199S,noice
Discharge, S7.1 cubic feet per second
24
22
t;:j::; 20
~~ ~~ 18
·>-Za: g;;!
16 ~t:
wal ... a: w< 14
12
10
0 20
0 2.0 z
0
() w
(/) 1.5 a: w
Q.
1-w 1.0 w
1.1..
~
~ 0.5
§
w > 0
0
40 60
BRADLEY RIVER AT TREE BAA REACH
CROSS SECTION
ao 100 120 140 160 160
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
VELCX::rrY PROALE
November 30, 1994, 100 percent ice cover
Discharge, 51.8 cubic feet per second
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
November 30, 1994, 100 percent ice cover
Discharge, 51.8 cubic feet per second
Figure C. Cross section and velocity distribution of the lower Bradley River at Treebar Reach
24
22
1-:E 20
UJ::J
UJ!-u..<
:!!:a 16 ·>-Za:: g~ 16 <t: >m lila:
u:l< 14
12
10
,0
Figure C. Continued.
BRADLEY RIVER AT TREE BAA REACH
CROSS SECTION
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
February 28, 1995, 1 00 percent ice cover
Discharge, 56.5 cubic feet per second
VELOCITY PROFILE
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
February 28, 1995, 100 percent ice cover
Discharge, 56.5 cubic feet per second
24
22
t;j:::; 20
~~ ;?;~ 18 ·>-Za: ~ii 16 c(t: >m Wa: iilc(
14
12
10
0 20 40 60
Cl 2.0 z
0 u w
(/) 1.5 a: w a..
1-w 1.0 w
LL.
;?;
~ 0.5
§
w > 0
0 20 40 60
Figure C. Continued.
BRADLEY RIVER AT TREE BAR REACH
CROSS SECTION
Water surface 13.21 n.
eo 100 120 140 160 180
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
April 4, 1995, minor shore ice
Discharge, 55.3 cubic feet per second
VELOCITY PROFILE
eo 100 120 140 . 160 180
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
April 4, 1995, minor shore ice
Discharge, 55.3 cubic feet per second
20
18
f-~ UJ::;,
UJf-u.<
16 ;;:;o .,_
Za;: ~~ 14 <f.. >-wCO _,a:
w<
12
10
0 20 40
BRADLEY RIVER BELOW FISH CAMP
CROSS SECTION
Water surface 12.80 lt.
60 80 100 120 140 160
DISTANCE FROM LEFT SANK. IN FEET
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
November 29, 1994, 100 percent ice cover
Discharge, 48.4 cubic feet per second
VELOCITY PROFILE
DISTANCE FROM LEFT BANK. lN FEET
Date of survey, ice conditions, and discharge
November 29, 1994, 100 percent ice cover
Discharge, 48.4 cubic feet per second
Figure D. Cross section and velocity distribution of the lower Bradley River below Fish Camp
20
16
1-:::: w::> WI-
IL<(
16 ~0
'>-Za: Q<e
!-0: 14 <Cf::: >m Wa:
U:<e
12
10
0 20 40
BRADLEY RIVER BELOW FISH CAMP
CROSS SECTION
Water sur1ace 13.9 n.
60 eo 100 120 140 160
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
January 12, 1995, 100 percent ice cover
Discharge, 42.6 cubic feet per second
VELOCrrY PROFILE
0 3.---~---.----~--~--~----~---r---.----~--~--~----.---~--~----~--· a
(.) w
Ul
a:
~ 2 f-
lii w
!L
~
~
(.) g ~ ~ oL---~---~'---'~--~ 'L---~--~----~~--~~~--~----~---~~--~---~~--~--~ o 20 40 eo eo 100 120 140
Figure D. Continued.
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
January 12, 1995, 1 00 percent ice cover
Discharge, 42.6 cubic feet per second
160
20
18
1-::;: w::::>
WI-u.<(
16 ;?;a
·>-Za: ~~ 14 <t->-waJ _.a:
w<
12
10
0 20 40
BRADLEY RIVER BELOW FISH CAMP
CROSS SECTION
60 80 100 120 140
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
March 1 , 1995, 1 00 percent ice cover
Discharge, 47.5 cubic feet per second
VELOCITY PROFILE
160
~ J .----r---,----,---~----~--~----~---r--~.---,---~----~--~----~--~----,
0 u w
(/)
a: le 2
tu w u.
~
~ u g
w > 0 ~--~----'--~~--~----~--~----~--~----~---'L--~----~--~----~--~--~
0 20 40
Figure D. Continued.
60 60 100 120 140
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
March 1, 1995, 1 00 percent ice cover
Discharge, 47.5 cubic feet per second
160
20
18
1-:::;;
UJ:l w,_
u.<(
16 ;;!;o
·>-Za::
Q<( t-a:: 14 <(I->-UJaJ -'a: UJ<(
12
10
0 20
Figure D. Continued.
BRADLEY RIVER BELOW FISH CAMP
CROSS SECTION
Water sur1ace 12.5 n.
40 60 eo 100 120 140 160
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
June 29, 1993, open-water baseline
April 5, 1995, minor shore ice
Discharge, 57.9 cubic feet per second
VELOCrrY PROFILE
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
AprilS, 1995, minor shore ice
Discharge, 57.9 cubic feet per second
18
1-::E UJ:> 16 UJI-
1.1.<( ;;:;o
'>-Za: 14 Qii !;( :::>1::: will 12 _,a: w<
Water surface 12.421!.
10
0 40
BRADLEY RIVER AT UPPER RIFFLE REACH
CROSS SECTION
80 100 120 140 160 180
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
June 30, 1993, open-water baseline
VELOCITY PROFILE
December 1, 1994, 100 percent ice cover
Discharge, 47.1 cubic feet per second
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
December 1, 1994, 100 percent ice cover
Discharge, 47.1 cubic feet per second
Figure E. Cross section and velocity distribution of the lower Bradley River at Upper Riffle Reach
20
1-:::E w::J WI-u.< 15 ~0 Water surface 13.0 ft. .,.. :Za: Q~
!<I-10 >-~~ w<
5
0 40
BRADLEY RIVER AT UPPER RIFFLE REACH
60
CROSS SECTION
80 100 120 140 160 160
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
June 30, 1993, open-water baseline
VELOCITY PROFILE
January 12, 1995, 1 00 percent ice cover
Discharge, 50.5 cubic feet per second
~ 3 r---~--~--~--~--~r---r---~--~--,----r---r--~----r---~--,----r--~---.
0
&i
(/)
a:
~ 2
1-w w u.
~
~ g
~ 0 L---~--~--~--~----~~~--._--~--~--~--_.~~----L---~--~~~--~--~
0 20 40 60
Figure E. Continued.
100 120 140 160
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
January 12, 1995, 1 00 percent ice cover
Discharge, 50.5 cubic feet per second
160
18
1-:::!l UJ::> 16 UJI-u.<(
~0
·>-Za: 14 Q<(
1-0: <t: >CD UJa: 12 ul<
10
0
Figure E. Continued.
BRADLEY RIVER AT UPPER RIFFLE REACH
CROSS SECTION
80 100 120 140 160 180
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions. and discharge
June 30, 1993, open-water baseline
VELOCITY PROFILE
March 1 , 1995, 1 00 percent ice cover
Discharge, 47.5 cubic feet per second
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
March 1 , 1995, 1 00 percent ice cover
Discharge, 4 7.5 cubic feet per second
18
1-:s
w:J HI WI-u.<(
;<!;o
·>-Za: 14 s~ <t:: >co ~~ 12
10
0
BRADLEY RIVER AT UPPER RIFFLE REACH
CROSS SECTION
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
June 30, 1993, open-water baseline
April 5,1995, some ice debris in left channel
Discharge, 56.9 cubic feet per second
VELOCITY PROFILE
~ 3 r---~--~---r--~--~----r---~--~---r---.--~---,----r---~---r---.--~--~
0
@
(/)
a:
~ 2
1-
UJ
UJ u.
~
t g
~ oL---~L-J_--~--~--~--~~--._--~--~--~--_.--~--~~--~--~---A--~--~
0 20 40 eo
Figure E. Continued.
100 120 140 160
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
April 5, 1995, some ice debris in left channel
Discharge, 56.9 cubic feet per second
180
I-:;
1.1.1:::> 1.1.11-u.<(
!l:;o
14
za:"" Q <( 12
r-a: ;;t:
~12 w<
10
BRADLEY RIVER AT LOWER RIFFLE REACH
CROSS SECTION
Water surface 11.911.
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
June 30, 1993, open-water baseline
VELOCITY PROFILE
November 30, 1994, 100 percent ice cover
Discharge, 46.8 cubic feet per second
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
November 30, 1994, 100 percent ice cover
Discharge, 46.8 cubic feet per second
Figure F. Cross section and velocity distribution of the lower Bradley River at lower Riffle Reach
t-::;
w:l w.-u..<
£:a
14
:i >-a: Q < 12
t-a: <t-~iii ul~
10
BRADLEY RIVER AT LOWER RIFFLE REACH
CROSS SECTION
Water surface 12.8 n.
8~--~--~--._--~--~--~--~---L--~--~--~--~--~--~--~~--~--._--~
0 20 40 60 60 100 120 140 160 180
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
June 30, 1993, open-water baseline
VELOCITY PROFILE
January 12, 1995, 1 00 percent ice cover
Discharge, 61.4 cubic feet per second
~ 3r---r---,---~--.---~---r--~---.---.---.--~---.--~---.----~--.---~--·
0
() w
(/)
a: :l: 2
t-w w u..
;;:t;
~
~ oL-~--~--~-'~--~--~~~~---W~~--~--~~--~--~~~--~~
0 20 40
Figure F. Continued.
60 100 120 140 160 160
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
January 12, 1995, 1 00 percent ice cover
Discharge, 61.4 cubic feet per second
1-:::!: w::>
WI-
1.1..<(
6o
·;,. Za; g~
<(I->-~Q'l w~
SRADLEY RIVER AT LOWER RIFFLE REACH
CROSS SECTION
14
12
10
8~--~--~--~--~--~--~--~--~--~--~--~--~--~--~--~~--~--~__J
0 40
Figure F. Continued.
100 120 140 160 180
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
June 30, 1993, open-water baseline
March 1, 1995, 1 00 percent ice cover
Discharge, 47.8 cubic feet per second
VELOCITY PROFILE
DISTANCE FROM LEFT BANK, IN FEET
Date of survey, ice conditions, and discharge
March 1, 1995, 1 00 percent ice cover
Discharge, 4 7.8 cubic feet per second
BRADLEY RIVER AT LOWER RIFFLE REACH
CROSS SECTION
14
ti:i::;
w::J "-!;(
;E;o
·>-Za: 12 Q~ !;( >I:: wiD _ja: w<
10
8~--~--~--~--~--~--~--~--~--~--~--~--~--~--~--~--~--~~~
0 20 40
Figure F. Continued.
80 100 120 140 160 180
DISTANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
June 30, 1993, open-water baseline
AprilS, 1995,noice
Discharge, 53.8 cubic feet per second
VELOCITY PROFILE
OIST ANCE FROM LEFT BANK. IN FEET
Date of survey, ice conditions, and discharge
April 5, 1995, no ice.
Discharge, 53.8 cubic feet per second