HYDROLOGIC DATA COLLECTION ACTIVITIES IN THE SOLOMON GULCH BASIN NEAR VALDEZ, ALASKA

By Bruce B. Bigelow

U.S. GEOLOGICAL SURVEY

Open-File Report 88-719

Prepared in cooperation with the

ALASKA POWER AUTHORITY

Anchorage, Alaska

1988

DEPARTMENT OF THE INTERIOR

DONALD PAUL HODEL, Secretary

U.S. GEOLOGICAL SURVEY

Dallas L. Peck, Director

For additional information Copies of this report can bewrite to: purchased from:

District Chief U. S. Geological SurveyU.S. Geological Survey Books and Open-File Reports SectionWater Resources Division Federal Center4230 University Dr., Suite 201 Box 25425Anchorage, Alaska 99508-4664 Denver, Colorado 80225

11

CONTENTSPage

Introduction............................................................ 1Data-collection sites and discharge records............................. 6

Solomon Gulch Tailrace near Valdez............................... 6Solomon Gulch Bypass near Valdez................................. 6Solomon Gulch at top of falls.................................... 10Solomon Gulch near Valdez........................................ 13

ILLUSTRATIONS

Figure 1. Map of Valdez area showing location of Solomon Lake andSolomon Gulch south of Port Valdez......................... 2

2. Map of Solomon Gulch downstream from Solomon Lake andlocation of U.S. Geological Survey data-collection sites... 3

3. Diagram of profile of Solomon Gulch and water diversionstructures................................................. 4

4. Schematic diagram of Solomon Gulch flow pattern.............. 55-9. Photographs showing:

5. Copper Valley Electric Association powerhouse on SolomonGulch ..................................................... 7

6. Tailrace downstream from Copper Valley Electric Associationpowerhouse................................................. 7

7. Solomon Gulch Bypass......................................... 98. Discharge measurement in Solomon Gulch Bypass, just upstream

from mouth of tailrace..................................... 119. Survey rod indicating height of water surface at peak flow

on October 11, 1986, 100 feet upstream from the Alyeska Pipeline Service Company bridge over Solomon Gulch......... 11

TABLES

Table 1. Discharge records at Solomon Gulch Tailrace near Valdez,September 1986 through September 1987...................... 8

2. Discharge records at Solomon Gulch Bypass near Valdez,September 1986 through September 1987...................... 12

3. Discharge records at Solomon Gulch at top of falls nearValdez, September 1986 through September 1987.............. 14

4. Discharge records for Solomon Gulch near Valdez, September1986 through September 1987................................ 15

in

CONVERSION FACTORS

For readers who may prefer to use metric (International System) units rather than inch-pound units, the conversion factors for the terms used in this report are listed below:

Multiply inch-pound unit bv

inch (in.) 25.4 foot (ft) ' 0.3048 mile (mi) 1.609 acre-foot (acre-ft) 1,233 cubic foot per second (ft3/s) 0.028317

To obtain metric unit

millimeter (mm)meter (m)kilometer (km)cubic meter (m3 )cubic meter per second (m3 /s)

SEA LEVEL

In this report "sea level" refers to the National Geodetic Vertical Datum of 1929 (NGVD of 1929)-- a geodetic datum derived from a general adjustment of the first-order level nets of both the United States and Canada, formerly called "Sea Level Datum of 1929."

NOTE

A section entitled "Accuracy of Records" is included under the description of the individual sites for which discharge is computed. The accuracy of streamflow records depends primarily on: (1) the stability of the stage-discharge relation or, if the control is unstable, the frequency of discharge measurements; and (2) the accuracy of observations of stage, direct (current meter) measurements of discharge, and interpretation of the data.

The U.S. Geological Survey has historically used subjective terms to describe the degree of accuracy of streamflow records. The term "excellent" means that about 95 percent of the daily discharge figures are within 5 percent of the true value; "good" records are within 10 percent of true value; and "fair" records are within 15 percent. Records are rated "poor" when they do not meet the above criteria. Different degrees of accuracy may be attributed to different parts of a given record (e.g. "fair" when affected by ice, but otherwise "good").

IV

HYDRQLOGIC DATA COLLECTION ACTIVITIES IN THE

SOLOMON GULCH BASIN NEAR VALDEZ, ALASKA

by Bruce B. Bigelow

INTRODUCTION

In 1981, the Alaska Power Authority (APA) completed construction of a dam and spillway at the north end of Solomon Lake near Valdez (fig. 1). As part of the APA - U.S. Geological Survey cooperative program, the Survey began to collect streamflow data in the Solomon Gulch basin in September 1986. This report briefly describes the water diversion facilities, their effects on streamflow, and the data*collection activities.

Elevation of the dam on Solomon Lake is 695 ft and the spillway elevation is 685 ft (from construction plans). Water from the lake is diverted, by means of two 48-inch diameter penstocks (figs. 2-4), to a Copper Valley Electric Association (CVEA) powerplant near tidewater at Port Valdez. From the powerplant, water is diverted (by various routes; see fig. 4) to the Valdez Fisheries Development Association (VFDA) fish hatchery, which lies across the Valdez Marine Terminal Highway from the plant. The hatchery also receives water from Solomon Gulch via the Falls Creek Diversion, located about 600 ft upstream from the mouth.

Solomon Gulch flows northerly into Port Valdez from the mountains southeast and across Port Valdez from the city of Valdez (fig. 1). The headwaters of the gulch originate at the base of several small glaciers at altitudes of 3,000 to 4,000 ft and flow northerly for about 8 mi to Solomon Lake. Water diverted for power generation draws the lake level down and substantially reduces flow in the natural channel of Solomon Gulch during winter months. In spring, runoff from melting snow and ice begins to refill the lake, and in most years the lake begins to overtop the spillway by early July. Water then flows through a small lake and eventually rejoins the natural channel below the dam. Between the lake and tidewater at Port Valdez, the channel is very steep, is incised in near-vertical rock walls, and includes a series of waterfalls. The channel itself is mostly bedrock, although the more gently sloping parts of the streambed are covered by gravel- to boulder-sized material.

The Geological Survey collected daily streamflow data at a site near the mouth of Solomon Gulch from July to December 1948 and from October 1949 through September 1956. Regulation and diversion from the dam since 1982 have significantly altered the natural flow characteristics of Solomon Gulch. In September 1986, data collection was begun in an attempt to determine mean daily discharge at four sites below Solomon Lake and thus document the effects of regulation and diversion of water on the flow at various points in the system. Periodic discharge measurements and continuous records of water stage are being obtained at two of the sites, and daily discharge values are being computed for all four sites. Descriptions of the

147°30'00"

61°00'

Figure l.~Valdez area showing location of Solomon Lake and Solomon Gulch south of Port Valdez.

146°20'00" 146°17'30"

Port Valdez15225996 Solomon Gulch Taiirace

near Valdez

15226000 Solomon Gulch near Valdez Fish hatchery

Powerhouse *= *..Terminal Highway

15225998 Solomon Gulch Bypass near Valdez

»*> 15225997 Solomon Gulchat top of fails near Valdez'Wine

Pipeline bridgeSolomon Gulch Penstock

1 KILOMETER

-61°05'00'

Figure 2.-Solomon Gulch downstream from Solomon Lake and location of U.S. Geological Survey data-collection sites.

VE

RT

ICA

L E

XA

GG

ER

AT

ION

X 5

MIL

ES

UP

ST

RE

AM

FR

OM

MO

UT

H

Figu

re 3

.-P

rofi

le o

f S

olom

on G

ulch

and

wat

er d

iver

sion

str

uctu

res.

Solomon Lake Reservoir

EXPLANATION PS Penstocks

UPS Unaerated penstocks PAS Aerated penstocks WW Warm water

15225997

Solomon Gulch

at Top of Falls

Falls Creek Diversion

I

Copper Valley Electric

Power Plant £±

Pump

15225998

Solomon Gulch Bypass

Tailrace Weir Pool

Valdez Fisheries

Development

Association

Fish Hatchery

©

15225996

Solomon Gulch Tail race

Discharge Measuring Section

15226000

Solomon Gulch

near Valdez

Port Valdez

Figure 4.-- Schematic diagram of Solomon Gulch flow pattern.

data-collection sites follow, and the records for September 1986 and water year 1987 (October 1, 1986 through September 30, 1987) are included in tables in this report.

DATA-COLLECTION SITES AND DISCHARGE RECORDS

Solomon Gulch Tailrace near Valdez

(USGS Streamgaging Station No. 15225996)

Description of site: Location is at weir in the discharge pool downstream from the CVEA powerhouse, 350 ft upstream from mouth of the tailrace at Solomon Gulch. Elevation is about 40 ft above mean sea level; flow is not subject to tidal influence.

Stage measurement and discharge values: Continuous stage record is obtained with an electronic data recorder located on the powerhouse "catwalk" and a pressure transducer installed in the weir pool. The concrete weir 35 ft below the powerhouse (fig. 5) provides a stable control for the gage pool. Water discharged into the tailrace (fig. 6) has passed through one or both turbines for power generation. Discharge values here represent flow past the weir and do not include any of the diversions to the VFDA hatchery.

Stage-discharge relation and discharge measurements: A stage- discharge relation developed for this site is verified by ongoing direct measurements near the weir. Twenty-six measurements were-made between September 1986 and August 1988.

Accuracy of records: The weir is virtually free of debris and does not appear to be affected by backwater from snow or ice. Records of discharge from the powerplant are available for comparison. Records of discharge at this site (table 1) are generally considered good.

Solomon Gulch Bypass near Valdez

(USGS Streamgaging Station No. 15225998)

Description of site: Location is in a pool at base of the farthest downstream falls on Solomon Gulch (fig. 7), 100 ft upstream from Solomon Gulch Tailrace and 300 ft upstream from the mouth at Port Valdez. Elevation is about 25 ft above mean sea level, and flow is affected (backwater) by extreme high tides on Port Valdez.

Stage measurement and discharge values: A continuous record of water stage in the gage pool is provided by an analog recorder driven by a gas- purge manometer system; the orifice is installed in the pool and the recorder is located in the CVEA powerhouse. Large boulders at the outflow from the pool create an extremely stable control for the gage pool.

Figure 5. - Copper Valley Electric Association powerhouse on Solomon Gulch.

Figure 6. - Tailrace downstream from Copper Valley Electric Association powerhouse.

Table I.-Discharge records at Solomon Gulch Tailrace near Valdez, September 1986 through September 1987

Day

Day

Discharge, in cubic feet p«r second, September 1986

Mean values

Day Day Day Day Day

12345

131138140135136

6789

10

101808983

104

1112131415

135132130122134

1617181920

135136134134131

2122232425

126135135131121

2627262930

97129126130126

September total - 3716 Mean - 124 Maximum - 140 Minimum - 80 Acre-feet - 7370

Discharge, cubic feet per second, water year October 1966 to September 1987

Mean values

Oct. Nov. Dec. Jan. Feb. Max. Apr. May June July Aug. Sept.

12345

6789

10

1112131415

1617181920

2122232425

262728293031

Total

Mean

Maximum

Minimum

Acre-ft

130130134120121

12613112912494

767278112133

124114119125128

129124125126117

114117102106105102

3587

HE

134

72

7110

104113111114105

7674797881

8587828180

83899Z

114111

11712111910588

9110510910697

2697

96.6

121

74

5750

10184818288

6281857884

8691959492

9592

119119119

113120117124126

12612112612011697

3154

102

126

78

6260

89928391

109

11493929179

8289889187

8778796983

8991878375

8496107103121122

2846

91.8

122

75

5650

125124123124121

117107109111118

118118118116114

120117115125126

126122127128124

94112128 ---

3327

119

128

94

6600

129123109107107

110100104103109

112111111106106

10588828385

8079807783

889296939695

3049

98.4

129

77

6050

9896959384

938282

103109

106111113112110

1101071059990

867245424.8

3846

.004660

2437.80

81.3

113

.00

4840

77454175101

901091069894

105122137141151

139138151150152

150150145136143

148146144143139131

3797

122

152

41

7530

138138139145146

137139141141144

146140134126134

134142140136126

126140134131135

134139139141140 -

4125

137

146

126

8180

139140139137139

141140143138146

146138134134137

141140139133134

132141138139133

129138133132144147

4284

138

147

129

8500

139143133142147

146146139137136

136116126126125

120116105122170

191184178180184

188190187184188113

4637

150

191

105

9200

176167196199165

186186166199201

194190176187191

192201188183180

183179185156135

132124134134139

5288

176

201

124

10490

Water year 1987 Total 43428.80 Mean 119 Maximum 201 Minimum .00 Acre-feet 86140

8

Figure 7. - Solomon Gulch Bypass.

Discharge values here represent flow over the spillway of the dam on Solomon Lake plus any inflow between the dam and the gage, minus the Falls Creek Diversion. Because channel conditions almost always prevent direct measurement of discharge near the gage pool, values of discharge at this site are determined by measuring discharge in Solomon Gulch below its confluence with the powerhouse tailrace and subtracting the discharge at the tailrace (station No. 15225996, Solomon Gulch Tailrace) at the time of measurement.

Stage-discharge relation and discharge measurements: A stage- discharge relation was developed for this site and is verified by periodic current-meter measurements. Twenty-three measurements were made between September 1986 and August 1988. On July 29, 1988, a direct measurement was also made between the gage pool and the mouth of the tailrace (fig. 8). The results verified the computed discharge with 1.2 percent.

Accuracy of records: The stage-discharge relation (rating curve) for this site is subject to considerable deviation or shifting. During summer and fall, various types of debris -- leaves, twigs, and dead salmon -- lodge between the boulders and raise the level of water in the gage pool. In winter, the stage-discharge relation is affected by backwater caused by snow and ice on the boulder control. Records of discharge (table 2) are considered good, except for those during periods of ice effect, which are rated as fair to poor.

Solomon Gulch at Top of Falls

(USGS Streamgaging Station No. 15225997)

Description of site: Location is at the top of a series of falls; 100 ft downstream from the Alyeska Pipeline Service Company bridge, and 0. 3 mi upstream from the mouth at Fort Valdez. Elevation is 400 ft above mean sea level, from topographic map.

Stage measurement and discharge values: Water stage is not being recorded. Daily discharge values for this site are determined by adding values of the Falls Creek Diversion, provided by employees of the VFDA hatchery, to daily discharge values for the Solomon Gulch Bypass site (station No. 15225998). Water is diverted to the hatchery via the Falls Creek Diversion, located about 1,000 ft downstream from this site and about 300 ft upstream from the bypass gage site.

Profiles of the high-water marks for the flood of October 11, 1986, and channel geometry on the upstream side of the pipeline bridge were surveyed in July 1987. Computations from this indirect measurement survey indicate a peak flow of 3,280 ft3/8 through the bridge opening. Figure 9 shows the maximum height of the water surface about 100 ft upstream from the bridge. At peak stage of the flood, water was in contact with the bottom upstream bridge stringer.

Discharge measurements: Only two direct measurements of flow have been made at the "Top of Falls" site -- on September 24, 1987 and on July 29, 1988.

10

Figure 8. - Discharge measurement in Solomon Gulch Bypass, just upstream from mouth of tailrace.

Figure 9. - Survey rod indicating height of water surface at peak flowon October 11,1986,100 feet upstream from the Alyeska Pipeline Service Company bridge over Solomon Gulch.

11

Table 2. -Discharge records at Solomon Gulch Bypass near Valdez, September 1986 through September 1987

Day

123* 5

Day

Discharge, cubic f««t per second. September 1986

Maan values

Day Day Day Day

138148965933

September total - 2477.1 Maan - 82.6 Maximum - 604 Minimum - 7.8 Acra-faat - 4910

6789

10

2544

20318493

1112131415

3818108.88.5

1617181920

8.38.8

2362

604

2122232425

351164782011

2627282930

8.47.97.87.88.8

Day Oct.

Discharge, cubic faat par second, water year October 1986 to September 1987

Mean values

Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept.

1 9.32 9.03 214 1845 94

6 327 128 119 10

10 828

11 214012 60313 57014 55515 247

16 11617 4818 2219 1220 11

21 2322 3623 1724 1525 11

26 1027 9.628 9.529 9.330 9.131 8.8

Total 5692.6

Mean 184

Maximum 2140

Minimum 8 . 8

Acre-ft 11290

9.113131413

1312121212

1212121212

1212121312

1212121111

1111111111 _

357.1

11.9

14

9.1

708

Water

1111111111

1111111111

9.59.59.59.59.5

9.59.59.59.59.5

8.58.58.58.08.0

7.57.58.59.5

1213

304.5

9.82

13

7.5

604

year 1987

1212121213

1314131412

11119.58.56.5

8.07.57.58.08.0

8.58.58.59.59.5

9.58.58.58.58.08.0

310.0

10.0

14

7.5

615

Total

8.07.57.57.57.0

7.06.56.56.56.0

6.06.05.55.55.5

5.05.05.05.04.5

5.56.57.58.59.5

101111

192.5

6.87

11

4.5

382

24234.2

1111121113

1314151617

1820212225

2627292319

161311109.3

9.08.58.48.29.09.1

474.5

15.3

29

8.2

941

Mean 66.4

8.68.58.48.89.0

8.78.58.49.39.6

8.78.88.76.86.7 .

6.67.99.59.59.5

9.68.36.76.76.7

6.78.4

111214 -

260.6

8.69

14

6.6

517

Maximum

1315151517

1617171717

1616171820

1820171717

1717151816

181617161717

519

16.7

20

13

1030

1618161616

1716151514

1414141414

1313131313

1314131312

1315151517

434

14.5

18

12

861

2140 Minimum 4.4

1313121212

116.76.66.46.2

6.48.5

14167183

216205222268369

349359360266262

331345309266250240

5094.8

164

369

6.2

10110

Acre-feet

197170157130201

330292197159148

142161164196183

127114987955

3623222641

504435324040

3689

119

330

22

7320

48070

214.4

2521520485

23413901040409329

19088683212

9.69.6

142317

111254168150

14694544722

6905.6

230

1520

4.4

13700

12

Accuracy of records: The direct discharge measurements indicate that computed discharges are from 5 to 10 percent low in the 150 to 200 ft s /s range. However, overall records of discharge at this site (table 3) are considered to be of fair to poor accuracy.

Solomon Gulch near Valdez

(USGS Streamgaging Station No. 15226000)

Description of site: Location is at mouth of Solomon Gulch at Port Valdez (sea level), 3.8 mi southeast of city of Valdez.

Discharge values: Neither discharge nor water stage are measured at this site. Computed discharge values represent the total flow for Solomon Gulch. This includes flow at Solomon Gulch Tailrace (station No. 15225996), Solomon Gulch Bypass (station No. 15225998), the Falls Creek Diversion, and all penstock diversions to the VFDA hatchery. Tables of daily diversion to the hatchery are provided by VFDA. However, because the hatchery discharges "used" water directly into Port Valdez, direct measurements of that discharge for verification are virtually impossible.

The average annual discharge of Solomon Gulch at its mouth for water years 1950-56 (7 years), before any regulation of flow, was 144 ft s /s; the computed mean discharge for water year 1987, adjusted for changes in storage in Solomon Lake, was 194 ft s /s, about 35 percent higher than the earlier, longer term average value. This higher value seems reasonable if it is compared to the nearest long-term station in a comparable environment, Power Creek near Cordova (USGS streamgaging station No. 15216000). The average discharge at Power Cre.ek for water years 1950-56 was 248 ft s /s. Mean discharge at Power Creek for the 1987 water year was 317 fts /s or 28 percenthigher than for the 7-year period.

In addition to the calculated "actual" daily flow values at the site,

the Geological Survey publishes an additional set of monthly flow values, adjusted to account for changes in storage in Solomon Lake. This is an attempt to "reconstruct" natural or unregulated runoff patterns for Solomon Gulch.

Accuracy of records: On the basis of comparison with Power Creek, and on the expected accuracy of records for other data-collection sites in the basin, records of discharge at the mouth of Solomon Creek (table 4) are considered good.

13

Day

Table 3. -Discharge records at Solomon Gulch at top of falls near Valdez, September 1986 ____________________through September 1987

Discharge, cubic feet per second, September 1986

Mean value*

Day

12345

138148965933

6789

10

2544

20318493

September total - 2481.2

Day Day Day Day

11121314IS

3818108.88.S

1617181920

8.38.8

2362

604

2122232425

351164782011

2627282930

8.49.08.88.89.8

Mean - 82.7 Maximum - 604 Minimum - 8.3 Acre-feet - 4920

Day Oct.

Discharge, cubic feet per second, water year October 1986 to September 1987

Mean values

Nov. Dec. Jan. Feb. Max. Apr. May June July Aug. Sept.

12345

6789

10

11121314

1516171819

2021222324

25262728293031

Total

Mean

Maximum

Minimum

Acre-ft

10102218494

32121110

828

2140603571557

249118492314

1224371816

12111111111010

5720

185

2140

10

11350

1014141514

1413131313

13131313

1414141415

1414141412

121212121212-~

396

13.2

15

10

785

1412121212

1212121212

11111111

1111111111

111010109.5

9.59.09.0

10111314

347.0

11.2

14

9.0

688

1414141314

1415141513

12121110

109.59.09.09.5

9.510101011

11111010109.59.5

353.5

11.4

15

9.0

701

9.59.09.09.08.5

8.58.08.08.07.5

7.57.57.07.0

7.06.5

. 6.56.56.5

6.07.08.09.0

10

11121313 ___---

236.0

8.43

13

6.0

468

1212131314

1516171819

20222324

2627283024

2017141214

15151414141515

552

17.8

30

12

1090

1515141515

1514141515

14141412

1212131111

1111131413

131312111214

---

397

13.2

15

11

787

1315151517

1617171717

16161718

2018201717

1717171518

16181718171818

524

16.9

20

13

1040

1719171717

1817151514

14141414

1413131313

1313141313

121315151618

443

14.8

19

12

879

1413121212

1217171717

171920

167

184216205222268

369349359360266

262331345309266250240

5167

167

369

12

10250

204177164137208

337299204166155

149168171203

19013412110586

6243302933

48575142394747

3906

126

337

29

7750

2811

2591530492

24114001050416330

191896934

1411111625

19131457

176

158154101564824

---

7037

235

1530

11

13960

Hater year 1987 Total 25078.5 Mean 68.7 Maximum 2140 Minimum 6.0 Acre-feet 49740

14

Table 4. - Discharge records for Solomon Gulch near Valdez, September 1986 through September 1987

Discharge, cubic feet per cond, September 1986 Mean values

D«y

12345

280297247204179

Day

6789

10

136134302277207

Day

1112131415

183160150141153

Day

1617181920

154155168207746

Day

2122232425

488310224162143

Day

2627282930

115147144148145

September total - 6506 M*an - 217 Maximum - 746 Minimum - 115 Acre-feet - 12900

September (adjusted for change in Solomon Lake storage) Mean - 201 Cubic feet per second per square mile - 10.20Runoff in inches - 11.39 Acre-feet - 11,960

Day

Discharge, cubic feet per second, water year October 1986 to September 1987Mean values

Oct. Nov. Dec. Jan. Feb. Mar. Apr. May June July Aug. Sept.

1 1492 ISO3 1664 3155 226

6 1687 1538 1509 144

10 932

11 223012 68513 65914 67815 391

16 25117 17218 15119 14820 149

21 16222 17023 15224 15125 138

26 13427 13728 12229 12530 12331 120

Total 9601Mean 310Maximum 2230Minimum 120Acre-ft 19040

123136134138128

9996

101100103

1071091049797

100106109132128

134138136120103

106120124121112

346111513896

6860

Hater

118999697103

97961009399

100105109108106

109106133133133

126133130137139

138133139134132114

359511613993

7130

year 1987

106109100107126

13111110910995

97104102104100

1009091

10296

1021041009789

98111120116134135

329510613589

6540

138136135136133

129118120122129

129129128126124

130127125135135

136133139141138

109128144

-=-

3652130144109

7240

145139126124125

129120125125132

136137138134136

136120116111109

101979695

101

106109113110114112

371712014595

7370

115113111110101

1109898120126

122127129126124

124122118112103

9987615720

5360136076 -

289596.512913

5740

Total 70162 Mean 192 Maximum 2230

Adjusted for

Oct.

Mean 291Cubic ft.per sec.per mi 2 14.8Runoff ininches 17.03Ac-ft 17.890

Nov.

79

4.01

4.474,690

Dec.

41

2.08

2.422,550

Jan.

39

1.98

2.262,370

change

Feb.

19

0.96

1.021,070

in storage

Mar.

51

2.59

3.003,150

90605690118

106126123115111

121138154159171

157158168167170

168168161155160

166163162160157149

432714017156

8580

Minimum

156158157163164

156157157157159

161154148140148

147155153149142

142157150147150

150157160163164 -

4621154164140

9170

159154152150152

154158161158166

166163160307327

363351368408510

488507505412402

467490449405401394

9607310510150

19060

353330307289365

493455353313301

295294307339325

264247220218242

244224217223242

255251239233245170

8853286493170

17560

2142094651740687

43715901240625541

395288254228212

210219211215206

203200248333294

287227198191171

125384181740171

24870

13 Acre-feet 139200

in Solomon Lake

Apr.

20

1.02

1.161,210

May

211

10.7

12.3713,000

June

436

22.1

24.7225,970

July

419

21.3

24.5225,760

Aug.

286

14.5

16.7217.560

Sept.

418

21.2

23.6824,870

Hater year 1987 Mean 194 Cubic feet per second per square mile 9.85 Runoff in inches 133.38 Acre-feet 140,100

15