Fr.Iip.Il ·~ US Army Corps of Engineers Omaha District

1 .fr.iiP.il ·~ US Army Corps of Engineers Omaha District

Annual R-epo·rt - 1990 Tributary Reservoir Regulation Activities (August 1989 - July 1990)

Pr•pared by ·Water Control Section Hydrologic Engineeri.ng Branch Entineering Division Otrlaha, Nebraska

December 1990 This Report is the Omaha District's portion of the Missouri River Division's '19'89-1990 Annual Report on Reservoir Regulation Activities MISSOURI RIVER DIVISION OMAHA DISTRICT SUMMARY OF 1989-1990 RESERVOIR REGULATION ACTIVITIES

SECTION PAGE

I. PURPOSE AND SCOPE 1

II. REFERENCES 1

III. RESERVOIRS IN THE OMAHA DISTRICT 1

A. Reservoirs With Flood Control Storage 1 1. Corps of Engineers Dams 1 2. Bureau of Reclamation Dams 2

B. Reservoirs Without Flood Control Storage 2

IV. TRIBUTARY RUNOFF 2

V. RESERVOIR ACCOMPLISHMENTS 8

A. Flood Damages Prevented 8 1. Corps of Engineers Dams 8 2. Bureau of Reclamation Dams 8

B. Recreation Usage 9

VI. RESERVOIR OPERATION 10

A. Previous Years Operation 10 1. Corps of Engineers Dams 10 a. Bear Creek Reservoir, Colorado 10 b. Chatfield Reservoir, Colorado 10 c. Cherry Creek Reservoir, Colorado 10 d. Bowman-Haley, North Dakota 11 e. Pipestem, North Dakota 11 f. Papillion Creek Basin, Nebraska 11 g. Salt Creek Basin, Nebraska 11 h. Snake Creek - Lake Audubon, North Dakota 11 2. Bureau of Reclamation Dams 12

B. Proposed Operations 12 1. Corps of Engineers 12 a. North Dakota 12 b. South Dakota 12 c. Colorado 12 d. Nebraska 13

i 2. Bureau of Reclamation 13 a. Canyon Ferry 13 b. Tiber 13 c. Yellowtail 13 d. Others 14

VII. MAJOR REGULATION PROBLEMS 14

A. Water Quality 14

B. Downstream Channel Capacity 14

C. Releases for Purposes Other Than Authorized Project 14 Functions

D. Potential Hazardous Conditions 14

VIII. WATER CONTROL MANUALS 21

IX. DATA COLLECTION PROGRAM AND PROCEDURES 21

A. Collection of Water Control Data 21

B. Automated Remote Sensors 23

C. Cooperative Hydrologic Programs 23

D. Water Quality 23

E. Sediment 24

X. FLOODING 24

A. Salt Creek Tributary Flooding, Nebraska 24 - Fall of 1989 1. General 24 2 . Pre flood Conditions 24 3. Flood Event 24

B. Perry Creek Basin Flood - May 1990 26 1. General 26 2. Preflood Conditions 27 3. Flood Event 27 4. Storm of 22-23 May 1990 29 5. Flood Stages 29

C. Eastern Nebraska and Western Iowa - June 1990 29 1. General 30 2. Preflood Conditions 30 3. Flood Events 30 ii

. t' D. Eastern Nebraska and Western Iowa - July 1990 33 1. General 33 2. Preflood Conditions 33 3. Flood Event 33 a. Southwest Iowa 33 b. Eastern Nebraska 34

XI. WATER CONTROL INITIATIVES 35

A. Missouri River Division Water Control Data 35 System Master Plan

B. Denver Model 36

c. High Pool Levels 36

XII. FERC Applications 36

XIII. TRAINING AND METHODS 38

XIV. PERSONNEL 38

APPENDIXES

1. MAP OF FLOOD CONTROL DAMS

2. PROJECT DATA SHEETS

3. TOTAL NUMBER OF FLOOD CONTROL RESERVOIRS IN OMAHA DISTRICT

4. REGULATION SHEETS FOR PAST YEAR

iii TABLES

1. PERCENTAGE OF NORMAL RUNOFF FOR REPORT PERIOD 3 (AUGUST 1, 1989 TO JULY 31, 1990)

2. PERTINENT 1990 WY PROVISIONAL PEAK DISCHARGES 6-7

3. FLOOD DAMAGES PREVENTED IN DOLLARS BY CORPS DAMS 8

4. FLOOD DAMAGES PREVENTED IN DOLLARS BY USER DAMS 9

5. RECREATION VISITATION IN HOURS 9

6. WATER QUALITY ISSUES AND PROBLEMS 15-20

7. WATER CONTROL SECTION WORK PRIORITIES 22

8. OMAHA DISTRICT TRIBUTARY LAKES - RESERVOIR STORAGE AND SEDIMENTATION RATES 25

9. PERTINENT GAGING LOCATIONS 31

10. PRECIPITATION SUMMARY (JUNE 10 - JUNE 17) 32

11. SELECTED STAGE REPORTS 34

12. UTILIZATION OF EXCLUSIVE FLOOD STORAGE ZONE 36

FIGURES

1. PERCENTAGE OF NORMAL RUNOFF 4

2. LONG TERM PALMER DROUGHT SEVERITY MAPS 5

3. STORM OF 18-19 MAY 1990, ISOHYETHAL MAP, PERRY CREEK 28 BASIN, SIOUX CITY, IOWA

. . . ' MISSOURI RIVER DIVISION OMAHA DISTRICT SUMMARY OF 1989-1990 RESERVOIR REGULATION ACTIVITIES

I. PURPOSE AND SCOPE. This annual report summarizes significant tributary reservoir regulation activities and tributary flooding within the geographic boundaries of the Omaha District. The period covered by this report is 01 August 1989 through 31 July 1990 and is referred to as the report period.

II. REFERENCES.

A. ER lll0-2-1400, 24 April 1970.

B. ER lll0-2-240, 8 October 1982.

c. MRD Letter, 1 October 1970, subject: Reservoir Regulation Reports.

D. MRD Letter, 21 August 1990, subject: Annual Division Water Control Management Report.

III. RESERVOIRS IN THE OMAHA DISTRICT. The Omaha District, Corps of Engineers, civil works boundaries include 414,900 square miles that comprise the Missouri River watershed above Rulo, Nebraska.

A. Reservoirs With Flood Control Storage. There are 35 tributary reservoirs with allocated flood control storage covered in this report. The dams are listed below. Included are 24 Corps of Engineers dams and 11 Bureau of Reclamation dams. The locations of these 35 tributary reservoirs are shown on Appendix 1 and pertinent data are presented in Appendix 2. Appendix 3 summarizes chronologically the closure date for each of these tributary reservoirs and the six mainstem dams.

1. Corps of Engineers Dams

1. Bear Creek Dam, co. 14. Pipestem Dam, N.D. 2. Bowman-Haley Dam, ND. 15. Salt Creek No. 2, NE. 3. Bull Hook Dam, MT. 16. Salt Creek No. 4, NE. 4. Cedar Canyon Dam, SD. 17. Salt Creek No. 8, NE. 5. Chatfield Dam, co. 18. Salt Creek No. 9, NE. 6. Cherry Creek Dam, co. 19. Salt Creek No. 10, NE. 7. Coldbrook Dam, SD. 20. Salt Creek No. 12, NE. 8. Cottonwood Springs Dam, SD. 21. Salt Creek No. 13, NE. 9. Kelly Road Dam, co. 22. Salt Creek No. 14, NE. 10. Papillion No. 11, NE. 23. Salt Creek No. 17, NE. 11. Papillion No. 16, NE. 24. Salt Creek No. 18, NE. 12. Papillion No. 18, NE. 13. Papillion No. 20, NE.

1 2. Bureau 2.f. Reclamation Dams

25. Boysen Dam, WY. 26. Canyon Ferry Dam, MT. 27. Clark Canyon Dam, MT. 28. Glendo Dam, WY. 29. Heart Butte Dam, ND. 30. Jamestown Dam, ND. 31. Keyhold Dam, WY. 32. Pactola Dam, SO. 33. Shadehill Dam, SD. 34. Tiber Dam, MT. 35. Yellowtail Dam, MT.

B. Reservoirs Without Flood Control Storage. There are two Corps of Engineers tributary lakes without allocated flood control storage included in this report. Both are subimpoundments of the Missouri River Main Stem Projects and were formed by the construction of relocations for transportation facilities and utilities. Lake Audubon, a subimpoundment of Lake Sakakawea, is located just northeast of Riverdale, North Dakota. Lake Audubon and Snake Creek Pumping Plant were to be major facilities of the Bureau of Reclamation's proposed Garrison Diversion Unit (GDU) Project. The GDU is presently being re-evaluated. While the project has not been deauthorized, it appears the scope of work will be scaled back and that irrigation will not be supported. Lake Pocasse, a subimpoundment of Lake Oahe, is located near Pollock, South Dakota. The Bureau of Reclamation planned to use this lake as a regulating reservoir for the proposed Pollock-Herried Irrigation Unit. The development of this unit, however, has not materialized. Both lakes are used for fish and wildlife and recreational purposes. Their locations are shown on Appendix 1 and pertinent data are presented in Appendix 2.

IV. TlUBUTARI RUNOFF.

Tributary flows during the report period were well below normal in most of the basin. Drought conditions continued but were not as severe as those experienced in 1987 through 1989. Table 1 shows calculated percentages of normal run-off at pertinent locations within the basin and Figure 1 shows the general trend of those percentages. The Long Term Palmer Reports for Drought Severity from years 1989 and 1990 are shown on Figure 2. Table 2 lists peak discharges at selected gaging stations including many reservoir release control points used by Omaha District.

Areas of extremely low run-off (less than 50% of normal) occurred in North Dakota, South Dakota, Montana and Wyoming. Corresponding river basins are: the James, Grand, Moreau, Heart, Powder, Tongue, and Beaverhead. These areas -are classified as "extreme" drought conditions by the 1990 Palmer Report.

Areas of 50% to 70% of normal run-off were in Colorado, south and central Nebraska, south and central Wyoming, southwest South Dakota, and most of central and northwest Montana. River basins in these regions include: the Platte, South Platte, North Platte, Wind, Big Horn, Belle Fourche, Cheyenne,

------~~------~----~--~.~~--~------~----~ ',I TABLE 1. Percentage of Normal Runoff for Report Period (Aug 1, 1989 to July 31, 1990}

AVBRAGE IDLOW INPLOW PROJECT ACRE-FEET ACRE-FEET % OF AVERAGE CORPS OF ENGINEERS BOWMAN HALEY DAM 2,486 21,568 12 BEAR CREEK DAM 18,969 39,847 48 CHERRY CREEK DAM 5,300 7,801 68 COLD BROOK DAM 297 567 52 PAPIO DAM 11 3,342 6,190 54 PAPIO DAM 16 208 1,112 19 PAPIO DAM 20 1,101 1,243 89 PIPESTEM DAM 3,852 25,682 15 SALT CREEK DAM 2 523 2,152 24 SALT CREEK DAM 4 1,862 4,012 46 SALT CREEK DAM 8 2,811 4,237 66 SALT CREEK DAM 9 1,705 2,661 64 SALT CREEK DAM 10 3,181 4,947 64 SALT CREEK DAM 12 3,005 6,246 48 SALT CREEK DAM 13 860 4,094 21 SALT CREEK DAM 14 4,933 8,206 60 SALT CREEK DAM 17 3,144 2,345 134 SALT CREEK DAM 18 11,720 29,545 40 TOTAL: 69,299 172,455 40

BUREAU OF RECLAMATION BOYSEN DAM 675,040 1,035,152 65 CANYON FERRY DAM 2,755,500 4,050,140 68 CLARK CANYON DAM 130,970 298,619 44 GLENDO DAM 742,424 1,227,909 60 HEART BUTTE DAM 15,220 99,521 15 JAMESTOWN DAM 2,564 29,466 09 KEYHOLE DAM 18,017 32,645 55 PACTOLA DAM 18,370 32,671 56 SHADEHILL DAM 34,643 73,647 47 TIBER DAM 829,615 669,491 124 YELLOWTAIL DAM 1,962,460 2,533,437 77 TOTAL: 7,184,823 10,082,698 71

3 N ·------

PAKL- CIIU eMS CW

ICAU IN MILU •=s25~0am~~==~··

4 FIGURE 1 DROUGHT SEVERITY (LONG TERM, PALMER) OCT 2e, 1989

MODERATE

\\~-,SEVERE EXTREME EXTREME NOAA/USDA JOINT AGRICULTURAL WEATHER FACILITY ...... ~- DROUGHT SEVERITY (LONG TERM, PALMER) AUGUST 4, 1 990

NOAA/USDA JOINT AGRICULTURAL WEATHER FACILITY ..... -~ ....,.,

Long Term Palmer Drought Severity Maps for October 1989 and FIGURE 2 August 1990. 5 TABLE 2

PERTINENT 1990 .WY PROVISIONAL PEAK DISCHARGES (C.F.S.) MAXIMUM MAXIMUM 1990 KN~ FLOOD DRAINAGE Pt;RIOO FLOOD AREA OF RECORD STAGE STAGE DISCHARGE STAGE DISCHARGE STREAM STATION (SQ. MI!.ES> (YEARS) (FEET) DATE (FEET) (CFS) DATE (FEET) (CFS) Red Rock River Blw. Lima Res., MT 570 68 1.1 07 JUN 1990 3.36 551 15 MAY 1933 6.40 2,500 Milk River At Havre, MT. 5,785 65 10.0 05 JUN 1990 6.68 1,850 12 APR 1899 19.30 20,000 A Milk River Nr. Saco, MT. 17,670 14 20.0 13 MAR 1990 6.76 1,300 03 APR 1978 24.20 12,400 B,C Milk River At Nashua, MT. 22,332 52 20.0 17 MAR 1990 9.27 1,700 18 APR 1952 31.38 45,300 B Missouri River Nr. Wolf Point, MT. 82,290 63 10.9 19 JAN 1990 10.29 13,500 25 MAR 1939 14.40 66,800 B,D Wind~River Riverton, WY. 2,309 &3 8.0 11 JUN 1990 6.27 2,480 15 JUN 1935 10.15 13,300 E Little Wind River Nr. Riverton, WY. 1,904 50 10.0 11 JUN 1990 5.98 2,970 17 JUN 1963 10.85 14,700 Wind River Blw. Boysen Res., WY. 7,701 40 N/A 01 JUL 1990 5.64 1,920 07 JUL 1967 13.35 13,500 Big Horn River At Kane, WY. 15,765 62 8.0 11 JUN 1990 4.58 6,310 16 JUN 1935 11.10 25,200 Yellowstone River At Miles City, MT. 48,253 64 13.0 14 JUN 1990 8.72 35,600 22 MAY 1978 16.50 102,000 Missouri River At Bismarck, N.D. 186,400 64 16.0 25 FEB 1990 8.97 311100 06 APR 1952 27.90 500,000 F,G N. ~ork Grand River At Haley, N.D. 509 56 17.0 11 FEB 1990 5.90 30 07 APR 1952 17.03 14,100 B,H Fall River At Hot Springs, S.D. 137 54 13.0 24 MAY 1990 4.63 399 04 SEP 1938 18.40 13,100 A Rapid Creek At Rapid City, S.D. 410 55 7.0 28 AUG 1990 4.93 204 09 JUN 1972 19.66 50,000 Belle Fourche River At. WY.-S.D. State Line 3,280 45 14.0 24 MAY 1990 11.88 1,980 18 JUN 1962 15.59 4,400 Pipestem Creek Nr. Pingree, N.D. 700 18 10.0 03 JUN 1990 5.55 21 20 APR 1979 11.60 2,520 I James River Nr. Grace City, N.D. 1,060 23 12.0 29 JUN 1990 6.71 294 13 MAY 1969 12.00 3,100 James River At Jamestown, N.D. 2,820 57 12.0 19 JUN 1990 3.50 80 13 MAY 1950 15.82 6,390 A 0\ James River At LaMoure, N.D. 4,390 42 14.0 03 APR 1990 7.10 89 14 APR 1969 16.17 6,800 James River At Columbia, S.D. 5,857 46 11.0 17 MAR 1990 4.99 5 24,25 MAY 1950 16.89 5,420 J James River At Ashton, S.D. 9,742 46 13.0 28 JUL 1990 6.09 259 24 APR 1969 20.63 5,680 K James River· Nr. Scotland, S.D. 20,653 63 13.0 27 MAY 1990 6.17 464 23 JUN 1984 20.45 29,400 Vermillion River Nr. Vermillion, S.D. 2,302 8 21.0 17 JUN 1990 13.52 1,410 23 JUN 1984 31.77 21,400 Big Sioux River At Akron, lA. 8,424 63 16.0 17 JUN 1990 14.45 5,550 09 APR 1969 22.99 80,800 Missouri River At Sioux City, lA. 314,600 94 36.0 19 MAY 1990 20.26 40,400 14 APR 1952 24.28 441,000 A Little Sioux River Nr. Turin, lA. 3,526 33 20.0 17 JUN 1990 22.55 19,500 21 JUN 1983 26.54 31,200 L Big Papio Creek Fort Crook, NE. 384 43 29.0 26 JUL 1990 ~27.45 7,130 21 MAY 1982 30.68 12,700 A,M Missouri River At Omaha, NE. 322,800 63 29.0 17 JUN 1990 26.89 84,400 18 APR 1952 40.20 396,000 North Platte River Nr. Sinclair, WY. 4,175 52 4.9 13 JUN 1990 6.30 6,030 11 JUN 1986 11.30 16,200 North Platte River Blw. Whalen Diversion, WY 16,425 82 4.5 02 JUL 1990 4.19 2,150 26 JUN 1955 9.85 22,000 Laramie River Nr. Ft. Laramie, WY. 4,564 76 6.5 16 JUL 1990 2.69 157 10 MAY 1973 9.40 6,260 North Platte River At Wy.-Neb. State Line 22,218 62 4.5 10 JUL 1990 3.37 1,690 02 JUN 1929 7.04 17,900 North Platte River At Bridgeport, NE. 25,300 86 8.0 04 OCT 1989 7.37 1,322 26 JUN 1899 5.39 24,900 A North Platte River At Lewellen, NE. 28,600 52 7.0 09 OCT 1989 5.34 1,450 04 JUN 1971 NR 13,500 North Platte River At North Platte, NE. 30,900 96 7.0 20 JUL 1990 4.95 2,680 11 JUN 1909 NR 29,600 South Platte River At Waterton, CO. 2,621 63 6 06 JUL 1990 2.43 907 23 APR 1942 5.68 5,700 Bear Creek At Morrison, co. 164 74 7.5 08 JUL 1990 5.59 372 24 JUL 1896 NR 8,600 South Platte River At Denver, CO. 3,861 98 9.0 29 MAY 1990 7.05 5,160 17 JUN 1965 18.66 40,300 Clear Creek At Derby, co. 575 75 8.0 29 MAY 1990 5.34 1,360 24 JUL 1965 8.97 5,070

J ~ TABLE 2 (Continued)

PERTINENT 1990 YY PROVISIONAL PEAK DISCHARGES (C.F.S.) MAXIMUM MAXIMUM 1990 KNOWN FLOOD '} DRAINAGE PERIOD fLOOD AREA OF RECORD STAGE STAGE DISCHARGE STAGE DISCHARGE STREAM STATION (SQ. MILES) (YEARS) (FEET) DATE (FEET) (CFS) DATE (FEET) (CFS) South Platte River At Henderson, co. 4,713 65 11.0 29 MAY 1990 8.90 8,510 06 HAY 1973 11.67 33,000 N South Platte River Nr. Kersey, co. 9,598 89 10.0 30 HAY 1990 6.98 6,050 08 HAY 1973 11.73 31,500 South Platte River At Julesburg, CO. 23,193 89 10.0 03 APR 1990 4.81 1,560 20 JUN 1965 10.44 37,600 0 South Platte River At North Platte, NE. 24,300 77 12.0 24 FEB 1990 2.98 751 03 JUN 1935 14.02 37,100 Platte River At Brady, NE. 56,200 54 5.0 21 JUL 1990 3.80 2,180 29 JUN 1983 NR 23,500 Platte River Nr. Grand Island, NE. 58,800 58 4.0 29 MAR 1990 2.76 3,050 06 JUN 1935 5.99 30,000 p Elkhorn River At Waterloo, NE. 6,900 72 17.0 16 JUN 1990 16.90 38,000 12 JUN 1944 16.60 100,000 A Salt Creek At Lincoln, NE. 684 42 20.5 26 JUL 1990 20.43 19,200 02 JUN 1951 26.15 28,200 Salt Creek At Greenwood, NE. 1,051 40 20.0 26 JUL 1990 25.50 38,900 13 JUN 1984 26.50 46,800 Platte River At Louisville, NE. 85,800 36 9.0 17 JUN 1990 9.16 67,000 14 JUN 1984 11.34 144,000 Q Missouri River At Nebraska City, NE. 410,000 62 18.0 19 JUN 1990 20.56 115,000 18,19 APR 1952 27.66 414,000 West Nishnabotna At Randolph, lA. 1,326 43 19.0 26 JUL 1990 23.50 27,200 26 HAY 1987 24.50 40,800 R East Nishnabotna At Red Oak, lA. 894 63 18.0 19 JUN 1990 19.25 13,000 13 SEP 1972 27.43 38,000 s Nishnabotna River Above Hamburg, lA. 2,806 65 16.0 27 JUL 1990 28.03 31,900 24 JUN 1947 26.03 55,500 T Missouri River At Rulo, NE. 414,900 42 17.0 20 JUN 1990 20.35 120,000 22 APR 1952 25.60 358,000 A) Site and datum then in use. B) 1990 Water year peak was ice affected ~ C) Maximum gage height = 26.70 feet on March 4, 1986 due to ice affect D) Maximum gage height for the water year occured on December 17 - ice affected E) Maximum gage height = 10.80 feet on December 30, 1983 F) Maximum discharge prior to Garrison Dam (1953) G) Since Garrison Dam:Max discharge= 68,900 c.f.s.;July 13, 1975;14.24 feet H) Maximum gage height= 17.10 on April 15,1950 I) Maximum of record ice affected J) Maximum gage height= 17.11 feet on March 24, 1987 K) Maximum gage height= 21.17 feet on April 13, 1969 (backwater from Snake Creek) L) Maximum gage height= 27.44 feet on February 19,1971 - backwater from ice H) Estimated stage at top of levee is approximately 40 feet N) Maximum gage height = 12.93 feet on June 17, 1965 0) Discharge is combined flow for channels 1,2,3 and 4. Maximum gage height occured in channel 1 & 2. P) Maximum gage height= 6.16 on March 27,1960- backwater from ice Q) Maximum gage height= 12.45 on March 30,1960 R) Maximum gage height = 24.8 feet on March 5, 1949 due to backwater from ice S) Maximum gage height = 28.23 feet on June 13, 1947 T) Maximum gage height = 28.27 on September 10, 1989 White, Milk, and Musselshell. These regions correspond closely to "severe" drought conditions on the 1990 Palmer Report.

River basins that experienced 71% to 100% of normal run-off were the Yellowstone River basin in Montana, the Shoshone River basin in Wyoming, and the Niobrara and Elkhorn River basins in Nebraska. The 1990 Palmer Report classified these areas as "moderate" drought conditions.

Regions that had more than 100% of normal run-off were the Marias River t basin in Montana, and the Boyer and Nishnabotna River basins in Iowa. The Marias River's discharge was above normal due to spring and early summer run off from mountain snowmelt. The Boyer and Nishnabotna Rivers discharges were 'f due to late spring, early summer rainfall. These areas are shown as "normal" to "moist" on the 1990 Palmer Report.

V. RESERVOIR ACCOMPLISHMENTS.

A. Flood Damages Prevented.

1. ~ of Engineers Dams. Flood damages prevented by the Corps of Engineers dams in 1990 and cumulative totals for each project are summarized in Table 3. Only the Salt Creek Reservoirs prevented or reduced downstream flooding.

TABLE 3. FLOOD DAMAGES PREVENTED IN DOLLARS BY CORPS DAMS

1990 Cumulative Total

Bull Hook (Havre Project) 0 20,664,000 Spring Creek (Lake Pocasse) 0 33,000 Bowman-Haley 0 0 Cottonwood Springs 0 0 Cold Brook 0 0 Cedar Canyon (Red Dale Gulch) 0 250,000 Pipestem 0 13,683,600 Papillion Creek Project 0 0 Chatfield 0 1,945,000 Bear Creek 0 450,000 Cherry Creek 0 163,267,000 Kelly Road (Aurora) 0 2,172,000 Salt Creek Project 16,700,000 43,794,000

16,700,000 248,096,600

2. Bureau .Qf Reclamation Dams. There was no downstream flooding prevented by any Bureau of Reclamation Dams this year. Flood damages prevented (both local and the Missouri River Main Stem) by the Bureau dams in 1990 and cumulative totals are summarized in Table 4.

8 TABLE 4. FLOOD DAMAGES PREVENTED IN DOLLARS BY USBR DAMS

1990 1990 1990 Cumulative Dam Local Main Stem Total Total

Clark Canyon 0 0 0 6,781,400 Canyon Ferry 0 0 0 69,684,000 Tiber 0 0 0 37,238,200 Boysen 0 0 0 27,967,700 Yellowtail 0 0 0 31,130,700 Heart Butte 0 0 0 11,824,100 Shadehill 0 0 0 7,742,300 Pactola 0 0 0 1,064,200 Keyhole 0 0 0 1,780,500 Jamestown 0 0 0 18,244,400 Glendo 0 0 0 28,905,300

TOTAL 0 0 0 242,362,800

B. Recreation Usage. Visitation hours for each project for FY89 and FY90 are tabulated in Table 5. Total visitation was up slightly more than 4 percent from 1989.

TABLE 5. RECREATION VISITATION IN HOURS

FY89 FY90 Percent Change

Bowman-Haley 126,600 123,415 -3% Cottonwood Springs 130,500 145,624 10% Cold Brook 318,600 359,384 11% Pipestem 307,045 272.805 -13% Papillion Creek #ll 2,845,185 2,938,724 3% Papillion Creek #16 2,072,665 2,049,825 -1% Papillion Creek #18 Not open for recreation Papillion Creek #20 4,051,390 3,690,300 -10% Papillion Creek Total 8,969,240 8,678,849 0% Chatfield 3,801,700 4,623,700 18% Cherry Creek 6,060,300 6,910,800 12% Bear Creek 320,900 400,700 20% Salt Creek #2 243,715 241,321 -1% Salt Creek #4 1,213,235 1,211,319 0% Salt Creek #8 1,002,640 928,316 -8% Salt Creek #9 1,075,670 1,046,344 -3% Salt Creek #10 289,470 278,192 -4% Salt Creek #12 699,565 687,523 -2% Salt Creek #13 290,042 267,680 -8% Salt Creek #14 3,579,725 3,485,749 -3% Salt Creek #17 3,928,190 3,872,594 -1% Salt Creek #18 3,735,710 4,192,075 11% Salt Creek Total 16,057,962 16,211,113 1%

TOTAL 36,164,692 37,726,390

9 VI. RESERVOIR OPERATION. Actual operations for the past year and proposed operations through calendar year 1990 are discussed briefly in the following subsections. Individual project operation summaries are contained in Appendix 4.

A. Previous Years Operation (August 1 1989 throug~ ~ ~ 1990).

1. Corps of Engineers Lakes. All Corps' tributary projects within the Omaha District were regulated in accordance with normal procedures during the period covered by this report. Only Bear Creek, Chatfield, Cherry Creek, Pipestem, Papio #ll, Salt Creek #8, #9, #10, #12, #14, #17, and #18 stored water in the flood storage zone or above their normal level at some time during the reporting period. A new low pool of record was established at Papio's #ll, #16, #20 and Salt Creek #13, while new second lows of record were established at Salt Creek #2, #9 and #18.

a. Bear Creek Reservoir. Colorado. During the report period, the district renewed the two temporary one year municipal and industrial water supply storage contracts for a to.tal of 74 acre feet under Section 6 of the Flood Control Act of 1944 (Public Law 534, 78th Congress), pending development of a long-term contract under the W'ater Supply Act of 1958, as amended. A revised Memorandum of Understanding (MOU) between the Corps of Engineers and the State of Colorado was signed on June 20, 1988, superseding the previous MOU dated May 11, 1977. Under the revised MOU, the State Engineer or his representative will determine the storage and releases necessary to satisfy downstream water rights requirements when the pool level is below elevation 5559.0 ft. MSL. This target elevation encroaches one foot into the flood storage zone and was selected to allow flexibility in targeting authorized pool levels. During the reporting period, no requests were received to change to continuous gated regulation to store water per the contract.

b. Chatfield Reservoir. Colorado. W'ater transfers along the South Platte River dropped the reservoir elevation to 5426 .19 ft. MSL on December 19, 1989. The Omaha District made a total of 8 release orders while the pool was in the flood control zone. The releases ranged from 200 cfs to 50 cfs and were required only to release inflows to maintain the target pool elevation of 5432.5. These releases occurred between March 31, 1990 and April 20, 1990. Before and after these dates, releases were made by the State Engineer. Releases made by the State Engineer varied from a maximum of 675 cfs on August 1, 1989 to 0 cfs from March 1 through March 29, 1990. The pool entered the flood control storage zone on March 25, 1990 and remained above elevation 5432 through May 7, 1990. Approximately 720 AF of "free" water was designated for transfer to Cherry Creek Reservoir to replace evaporation losses owed to the river as required by the State Engineers Office. All release orders during the reporting period were made by the State Engineer or his representative.

c. Cherry Creek Reservoir. Colorado. On April 1, 1988, the State of Colorado, through the State Engineer, implemented strict administration of water rights within the Cherry Creek Basin. When a senior river call is in effect, Cherry Creek Reservoir is required to pass inflow through the project. Releases from the project were coordinated by the W'ater

10 Control Section to comply with downstream river calls as determined by the Colorado State Engineers Office. A total of 8 release orders were made during the report period. The releases were made to release inflows to meet target pool elevation. Releases varied from 45 cfs to 0. Gate changes were ·made between March 30, 1990 and April 20, 1990.

d. Bowman-Haley. North Dakota. Beginning on August 21, 1989 and ending on October 3, a release of 2 cfs was made through the low level drawdown tube. Approximately 175 acre feet of water was discharged from the reservoir. This release was made for two reasons: (1) to flush any sediment buildup that may have occurred around the intake of the low level tube and (2) to release poor quality reservoir bottom waters.

e. Pipestem. North Dakota. Beginning on November 9, 1989 and ending December 10, 710 acre-feet of water stored in the flood control zone was released from the reservoir prior to winter freeze-up. The gates remained closed the spring and summer of 1990 as below normal run-off precluded the necessity for any gated release.

f. Papillion Creek Basin. Nebraska. Dam site #18 gate closure was held on December 7, 1989. Due to drought conditions, no low level releases were accomplished this year. The stilling basin seepage situation at the dam site #20 continues to be monitored closely. After analyzing all of the investigation data to date, no dam safety problems related to the stilling basin seepage have been identified.

g. Salt Creek Basin, Nebraska. During the summer of 1990, the Nebraska Game and Parks Commission requested that the lake level of Salt Creek #9 be lowered by ten feet to allow construction of islands in the upper end of the lake. The gate was opened on June 4, at a discharge of 34 cfs. I The lake level was reduced from 1270.4 ft MSL June 4 to 1261.4 ft MSL on June 30. I Releases were required from Salt Creek #18 to meet downstream senior water rights on July 27 - August 22, 1989, May 2 - May 4, 1990, and June 26 - July 20, 1990. A release was made from Salt Creek #18 on October 23 - November 9, 1989 as requested by the Nebraska Game & Parks Commission to lower the reservoir level 24 inches to reduce shoreline erosion.

h. Snake Creek .:. Lake Audubon, North Dakota. Lake Audubon was operated in accordance with the 1987 Letter of Understanding between the Corps, the Bureau of Reclamation, the Fish and Wildlife Service, and the North Dakota Game and Fish Department. During the fall and winter months, the lake level receded from releases down the McClusky Canal and evaporation to elevation 1846 ft. MSL. Beginning on April 5 and running intermittently until April 22, a total of 37,500 acre feet of water was pumped into Lake Audubon from Lake Sakakawea resulting in a pool elevation of 1847.2 ft. MSL, just short of the target pool of 1847.5 ft. MSL. During the months of May, June, and July, pumping was conducted periodically in order to maintain a level pool. The installation of a hydraulic powered operator on the control gate on the conduit between Lake Sakakawea and Audubon Lake is scheduled for completion in November 1990.

11 2. Bureau of Reclamation Dams. Reservoir operations at the eleven Bureau of Reclamation projects in the Omaha District were carried out in accordance with normal regulation procedures during the period covered by this report. None of the eleven Section 7 Bureau of Reclamation reservoirs stored water in the flood storage zone this year. No orders regarding flood control releases were issued by the Omaha District. Releases throughout the period were reduced to the absolute minimum required to meet authorized purposes. A number of the reservoirs set new record low pools. The only exception was Lake Elwell (Tiber Dam) , where inflows and storage were above average. See the individual project summaries for additional detail.

B. Proposed Operations.

1. Corps of Engineers. With the exception of Bear Creek, Cherry Creek, Chatfield and Pipestem, all Corps of Engineers tributary dams have ungated service outlets and no gate operations are normally required except for occasional opening of the low level outlets for various purposes. Releases to meet downstream water rights can be expected at Bowman Haley, Cold Brook, Chatfield, Cherry Creek, and Salt Creek #18. Evacuation of stored flood water in these projects is scheduled as soon as practicable after each flood event.

a. North Dakota. Flood releases from Pipestem Dam will be coordinated with those from the Bureau's Jamestown Dam. The low level gate at Pipestem will be opened when water is flowing over the drop inlet to assist in the improvement of lake water quality. At Bowman-Haley Reservoir, the water improvement program calls for releases from the low-level drawdown tube during periods of pronounced lake water stratification that typically occurs in late winter and again in late summer (target date July 15). If the local sponsor concurs and winter downstream conditions permit, water will be evacuated from ,the lower elevations starting in early February 1990.

b. South Dakota. Cold Brook reservoir inflows up to 1.1 cfs will be released to the Larive Lake Resort when requested to meet their water right.

c. Colorado. At Chatfield Reservoir, the pool level is expected to fluctuate between elevations 5423 and 5432 ft. MSL at all times except during prolonged periods of drought or excessive run-off. Each year, from May 1 to August 31, the pool level is not expected to fall below elevation 5426.85 ft. MSL (20,000 AF) for recreational purposes. Storage of water above elevation 5426.85 to elevation 5432.0 ft. MSL will depend on the availability of free water and/or excessive run-off and/or the desire of the City of Denver to store water. If free river conditions exist and the pool elevation rises into the exclusive flood storage zone, the Corps will request that one-half foot be held and released later in exchange for Cherry Creek Reservoir's evaporation losses. During the Colorado irrigation season, inflows to Cherry Creek Reservoir will be calculated by the Water Control Section and the State Engineer on a daily basis and releases will be balanced on a weekly basis to comply with State water rights. A Memorandum of Understanding will be developed between the Corps and State Engineer's Office to outline regulation responsibilities of the low flow gates and the reservoir

12 pending the response to the State's request to raise the level of multi purpose pool level. The sediment gate flushing will be scheduled in the fall if sufficient water is available. A fall flush is necessary for the improvement of water quality and to avoid fish kills. Flushes will not be scheduled during the December through March period. The flushing schedule utilizes approximately 267 AF of water. At Bear Creek Reservoir, the low level gate will be opened when practical during the June through August period when the lake typically stratifies to assist in the improvement of lake water quality if requested. Depending on the status of the temporary water supply contracts during the 1991 irrigation season, gated releases can be anticipated at Bear Creek Reservoir.

d. Nebraska. At Salt Creek Dam #18, releases of inflow up to a total of 11.57 cfs may be made. Releases up to 3 cfs without proving inflow will be made when required to satisfy downstream water rights. At Stage Coach, Salt Creek #9, the low level gate will remain open and the pool will fluctuate near elevation 1261 ft. MSL to allow the Nebraska Game and Parks Commission to complete construction of islands in the upper end of the lake. Low level releases will be made when practicable from the Papio projects to allow water to be discharged from lower elevations in an attempt to improve lake water quality.

2. Bureau of Reclamation. As in the past, the Bureau will continue to operate their reservoirs to meet flood control commitments and to coordinate operations with other interests to achieve optimum use of water resources. Generally, all reservoirs will be operated as close to the top of their conservation pools as possible. Pertinent special operating plans are described as follows: Boysen, Canyon Ferry, Clark Canyon, Tiber and Yellowtail Reservoirs require evacuation and refill of joint-use storage for flood control based on mountain run-off inflow forecasts.

a. Canyon Ferrv. The Canyon Ferry Reservoir Operating Plan requires that releases are adjusted as soon as the storage has peaked, usually in June or July, so the pool will be drawn to near elevation 3780 by the following March 1. In addition, the Montana Power Company will try to limit releases from Hebgen Reservoir to maintain Canyon Ferry pool below elevation 3794 after December 1. Storage below elevation 3794 prior to winter freeze up is des ired to prevent ice jam problems at the upper end of the lake. Beginning near the first of January, releases will be set based on the most probable spring inflow forecast to allow the reservoir to fill to elevation 3797 near the end of June.

b. Tiber. In accordance with the Water Control Agreement, the joint-use zone at Tiber Reservoir will be vacated to elevation 2976 by March 1. March-June releases are based on forecasted inflows with the objective of filling Lake Elwell to elevation 2993 ft. MSL by the end of June. However, if necessary, March-June releases may be based on filling the reservoir to as high as elevation 3008 ft. MSL by the end of June to provide replacement storage and assist the Corps in the operation of the main stem reservoir system.

c. Yellowtail. Yellowtail Reservoir will be regulated to be no higher than elevation 3630 ft. MSL by November 30 to reduce chances of headwater ice problems. The drawdown will continue through the winter months so that the pool elevation will be no higher than 3605 ft. MSL before the

13 beginning of spring run-off based on a normal run-off forecast. March through July releases will be based on forecasted inflows with the objective of filling Yellowtail Reservoir to elevation 3640 by the end of July.

d. Others. Replacement storage up to a combined total of 1,075,500 acre-feet can be made available in Clark Canyon, Tiber, and Canyon Ferry Reservoirs on a forecast basis. Fresno Reservoir in Montana is lowered each year and regulated to provided flood control in accordance with a June 4, 4 1957, Letter of Understanding. In addition to the reservoirs covered in this report, other Bureau reservoirs, without allocated flood control storage t space, will provide flood control in their normal operation of storing I seasonal run-off. Some of these projects are Gibson Dam in Montana and Bull Lake, Pathfinder, Seminoe, and Buffalo Bill Dams in Wyoming.

VII. H&lQR REGULATION PROBLEMS. Regulation problems experienced during the period of this report are discussed briefly in the following paragraphs.

A. Water Quality. Water quality problems including algal blooms and low dissolved oxygen exist at certain tributary reservoirs. The principal water quality issues and problems at each of the projects during 1989 are listed in Table 6.

B. Downstream Channel Capacity. Inadequate or reduced channel capacity is a problem below many of the tributary reservoirs. Encroachment by natural plant growth due to low flows, by flood deposits left in place, and by human construction and agriculture practices are common. In some cases, downstream channel capacity is significantly less than flood control releases. For example, the channel downstream of Cold Brook Dam is undefinable due to residential construction. The channel capacity of the South Platte River below the Tri-Lakes projects hinders or prevents releases in accordance with the three-reservoir (Chatfield, Bear Creek, and Cherry Creek) plan of regulation to evacuate flood storage. Compounding this situation is the fact that the reservoir design routings for Chatfield, Bear Creek and Cherry Creek Reservoirs were made independently of each other and that the individual routings neglected 1) the effect of the releases from the other two dams in the three-reservoir system, 2) the effect of the incremental run-off below the dams, and 3) the actual channel capacity below the three dams.

C. Releases ill Purposes other than Authorized Pro1ect Functions. Inquiries and requests received from states, cities, and other organizations for the release of water from the various projects for other than authorized purposes such as irrigation, water supply, and improvement of water quality. These requests pertain to supplemental discharges from the conservation pool or the retention of water and slow down of releases from the flood storage zone.

D. Potential Hazardous Conditions. A potential problem exists if water is released over the proj e.ct spillways where the land below the spillway has not been acquired and urban areas now exist. A hazard-to-life condition exists if a significant flow of water is discharged over the spillways at Cherry Creek Dam and Kelly Road Dam in Denver, Colorado; Salt Creek #17,

-·----· ------~--··-~---~--:--~---~-~--..,...... ~------

TABLE 6

WATER QUALITY ISSUES AND PROBLEMS IN MRD LAKES 1%9 OMAHA DISTRii;J

Algal Fish Potential Proble• * EPA AMbient Water Quality ** State Standard Project Blooms Kills Areas Criteria: Exceedances Exceedance

lake Audubon, Winter Kills IMPOUNDMENT: arsenic, Iron, IMPOUNDMENT: dissolved oxygen, North Dakota •anganese, dissolved oxygen, pH. Sub impoundment lead, unionized a..onla, pH. lake Sakakawea Yes No

Pocasse, Agrlcul tural IMPOUNDMENT: arsenic, Iron, IMPOUNDMENT: dissolved oxygen, South Dakota Runoff dissolved oxygen, pH, mercury, pH, unionized ammonia. Sub impoundment Containing •anganese, unionized a.. onla, lake Oahe Yes No · Pesticides and lead, copper. Nutrients ...... Winter Kills V1

Bowman-Haley, Ectogenic INFLOWS: Iron, sulfate, pH, INFLOWS: pH, sulfate. North Dakota Meromixis boron, manganese. Tributary Yes No RESERVOIR: Iron, pH, sulfate,. RESERVOIR: pH, sulfate. nitrate, manganese, unionized ••on fa. RELEASES: pH, sulfate. RELEASES: Iron, manganese, sulfate, unionized a..onla.

Pipes tell, Winter Kills INFLOWS: arsenic, Iron, pH, INFLOWS: sulfate, pH, North Dakota Algal Toxins •anganese, sulfate, dissolved dissolved oxygen. Trtbutary oxygen, unionized ammonia. No No RESERVIOR: arsenic, Iron, pH, RESERVOIR: pH, dissolved 11anganese, unlonhed ammonia, oxygen. dissolved oxygen, cadmium. RELEASES: dissolved oxygen, RELEASES: arsenic, Iron, pH. 118nganase, dissolved oxygen, lead.

* This column contains pesticides d,tected In project waters which are not covered by atate or federal standards. ** See the 1989 Water Quality Management Program Annual Report for 1989 Exceedancea Algal flail Potential Pr.obt .. * EPA A~tent Vater Quality** State Standard Project BloOIIS Kflh Areas Crlterl8: Exceedancea Exceec:lancea

Cottonwood Springs, IMPOUIIDMEIIII un.easured. IMPOUIIDMEJIT: Untleasured. South Dakota (\eaa than 1 acre-foot) (lese than 1 acre-foot) Tributary llo llo

Cold Brook, IIIFLQVS: lnter•lttent·un.eaaured. IIIFLOUS: lntar•lttent·unmeaaured. South Dakota Tributary RESERVOIR: arsenic, ..rcury, RESERVOIR: dtaaolved oxygen. Yea llo dissolved oxyten, unionized -.on fa. RELEASES: lnter.lttent·unmeaaured. r> .... RELEASES: lnter•lttent·un~~~eaaured •

Cherry Creek, Rapid IIIFLOVS: arsenic, Iron, IIIFLOVS: Iron, boron, copper, Colorado Urban hat I on •anganese. •anganese, dissolved oxygen, Tributary Winter Kills arsenic, ca~lu., lead, nickel, Yes tlo Bacterial RESERVOIR: anenlc, Iron, lead, selenh•, zinc. Conta•lnatfon •anganese, dlaaolved oxygen, Si11azine unionized ...onia. RESERVOIR: ca~lu., lead, Iron, dissolved oxygen, copper, boron, RELEASES: Iron, •anganese. arsenic, zinc, aelenlu., nickel, phosphate, •anganese. RELEASES: dlasolved oxygen, Iron, ca~IUII, •anganese.

Chatfield, Urbanization IIIFLOVS: araenlc, copper, INFLOWS: arsenic, dissolved oxygen, Colorado ContaMination •anganese, Iron, lead. Iron, boron, cad.lu., nickel, Tributary Fro lead, ..nganese, zinc, copper, llo llo Martin Marietta sel~IUII, phosphate. Low Dissolved RESERVOIR: dlsaolved oxygen, Oxygen Iron, arsenic, •anganese. RESERVOIR: Iron, lead, dissolved oxygen, boron, cadllfUII, copper, RELEASES: Iron, •anganese, •anganese, zinc, phosphate. lead, araentc. RELEASES: dlaaolved oxygen, Iron, boron, arsenic, ca~fum, copper lead, aanganeae, nickel, zinc, aelenlu., phosphate.

* This column contafna pesticides detected In project waters which are not covered by state or federal standards. ** See the 1989 Vater Quality Management Program Annual Report for 1989.Exceedances - _._,.._,.

Algal Fish Potential Problem * EPA Alibi ent Water Qual tty ** State Standard Project Bloo11s Kills Areas Criteria: Exceedances Exceedancea

Bear Creek, Bacterial and INFLOWS: arsenic, copper, INFLOWS: boron, copper, Iron, Colorado Viral sulfate, •anganese, lead, arsenic, dissolved oxygen, Tributary Conta11lnatlon Iron. sulfate, lead, cadlllu., zinc, Yea No Urbanization •anganese, nickel. Low RESERVOIR: dissolved oxygen, Dissolved Oxygen Iron, copper, •anganese, RESERVOIR: arsenic, copper, Iron, Ylnter Kills arsenic; lead. dissolved oxygen, lead, •anganese, boron, cadmlu., zinc, nickel, RELEASES: arsenic, copper, selenlu.. •anganese, lead, Iron, pH, unionized a.. onla. RELEASES: •anganese, copper, Iron, lead, dissolved oxygen, pH, boron, unionized a.. onla, arsenic, nickel, selenium, silver, zinc.

Pawnee Lake, Bloac:c:UIIUlatlon INFLOWS: arsenic, Iron, •anganese. INFLOWS: none Identified. Salt Valley of Mercury and dissolved oxygen. Reservoir Chlordane RESERVOIR: dissolved oxygen, Nebraska Algal Toxins RESERVOIR: arsenic, Iron, •anganese. atrazlne. Tributary Yea No RELEASES: arsenic, Iron, Manganese. RELEASES: none Identified.

Olive Creek Lake, Bloaccumulatlon INFLOWS: none Identified. INFLOWS: none Identified. Salt Valley of Mercury and Reservoir Chlordane RESERVOIR: arsenic, Iron, manganese, RESERVOIR: dissolved oxygen, Nebraska Algal lox Ins dissolved oxygen, unionized ammonia. atraztne. Tributary No No RELEASES: none Identified. RELEASES: none Identified.

Yankee Hill Lake, BloaccUIIIUlatlon INFLOWS: Mercury. INFLOWS: 11ercury. Salt Valley of Mercury and Reservoir Chlordane RESERVOIR: arsent c, l.ron, •anganese, RESERVOIR: dissolved oxygen, Nebraska Algal lox Ins dissolved oxygen, Mercury. atraztne. Tributary No No RELEASES: none Identified. RELEASES: none Identified.

* This colu.n contains pesticides detected In project waters which are not covered by state or federal standards. ** See the 1989 Yater Quality Management Progra• Annual Report for 1989 Exceedancea Algal Fi~h Potential Pro~le• • EPA Allblent Ueter Clualfty •• ·Stab 'tilnclitrd BJo011• Ktll• Are11s criteria: Excee~,n~•• · Exceedarn:es

Vagpn Trtin Lake, BI oac:cUIIU l atl on JNf~OW$; none l~entlfled. SIIU VaUey of Nercurya.,d aeurvofr Chlordtma IE$JRYOIR: dl•solyed oxygen, Nebraska Algal Toxins RESERVOIR: none ldentlfltd. atrazln,, ..rcury. · Tributary No RELJASE': none Identified. RELEASES: nonJ Jdentlfled.

HotJ!Ie!J Lake, Bioac:c:UIIUlation INF~~s: !lrtanlc. JNfL0~5: none Identified. Salt Valley of Mercury and Reservoir Chlordane R~S,RYOII: arsenic, pH, Iron, REsERVOIR: dlseolved oxygen, Nebraska Algal Toxins ..n,anese, dissolved oxygen, atrulne. · Tributary No No lea4. RELEASES: none Identified. RELEASES: none Identified.

'tuestelll Lake, Bioi!CC:'I!RI,Ilatlon INFLOWS: nona Identified. I"FLOUS: ~one Identified. Salt Valley of Hen:ury and Reservoir Ch l orc:h~ne RES~RYOIR: tre•nlc, Iron, RESERVOIR: dissolved oxygen, Nebraska Algal Toxins dissolved OJygen, ..ngane1e. atrazlne~ Tributary Yes No RELEASES: none Identified. RELEASES: none Identified.

East Tl!lln Lake, Bioac:c:uaiulatlon INFLOWS: arsenic, Iron, •ercury, INFLOWS: •ercury. Salt Valley of Mercury and ..neaneee. Reservoir Chlordane RESERVOIR: dissolved oxygen, Nebraska Algal Toxins RESERVOIR: arsenic, Iron, •anganese, 8trazlne. · Tributary Yes No Atrazine dissolved oxygen. Alac:hlor RELEASEs: ..rcury. Si•ulne RELEASES: ara11nlc, ..rcury. Metolachlor

Vest Twin Lake, Bioaccu.ulatlon INFLOWS: nqoe Identified. INFLOWS: none Identified. Salt Valley of Mercury and Reservoir Chlordane RESERVOIR: ..rcury, atrazlne. Nebraska Algal Toxins RESERVOIR: •ercury, arsenic, Tributary Yes No \linter Kills Iron, •anganese, unionized RELEAS~S: none Identified. Metotac:hlor a-onla. Simazlne RELEASES: none Identified • .---yhts-colu.n contains pesticides detected In project water• which are not covered by 1tate or federal standards. ** See the 1989 Vater Quality Management Progra• Annual Report for 1989 Exceedances

--- Algal Fhh Potential Probla• * EPA A~lent Water Quality** State Standard Project Blooms Kills Areas Criteria: Exceedances Exceedances

Stagecoach Lake, BI oaCCUIIUlett on INFLOWS: none Identified. INFLOWS: none Identified. Salt Valley of Mercury and Reservoir Chlordane RESERVOIR: araentc, Iron, aanganese. RESERVOIR: diaaolved oxygen, Nebraska Algal Toxins atraztne. Tributary No No Metolachlor RELEASES: dissolved oxygen, arsenic, Iron, manganese. RELEASES: atrazine.

Conestoga Lake, BioaccUIIulation INFLOWS: none Identified. INFLOWS: none Identified. Salt valley of Mercury and Reservoir Chlordane RESERVOIR: araenlc, pH, Iron, RESERVOIR: dissolved oxygen, Nebraska Algal Toxins aanganeae, •ercury, dtasolved atraztne, aercury. Tributary No No oxygen. RELEASES: atrazlne. RELE~SES: Iron, aanganese. 1-' \0 Branched Oak Lake, BloaccUIIulatton INFLOWS: none Identified. INFLOWS: none Identified. Salt Valley of Mercury and Reservoir Chlordane RESERVOIR: ·araenic, Iron, RESERVOIR: dlsaolved oxygen, Nebraska Algal Toxins aanganese, dlasolved oxygen, atrazlne. Tributary Yes No unionized a.. onta. RELEASES: none Identified. RELEASES: aanganese, Iron, araenlc.

Glenn Cunnlnghaa Lake, Oil Spills ·JNFLOWS: araenlc, cyanide, unionized INFLOWS: fecal collfora Papillion Creek 8 t oaccuaulatt on a ..onta, Iron, aanganese, nitrate, bacteria. Reservoir of Mercury and aelenlua. · Nebraska Chlordane RESERVOIR: dlsaolved oxygen, Tributary Yes No Bacterial aercury. Contaatnation RESERVOIR: araenlc, Iron, lead, Algal Toxins aercury, unionized aaaonla, aanganeae, dl'asolved oxygen. RELEASES: aercury.

RELEASES: araenlc, aercury, unionized aaaonla. Iron. aanganese.

* This coluan contains peatlcldas detected In project watera which are not covered by atate or federal standards. ** See tKe 1989 Water Quality Management Prograa Annual Report for 1989 Exceedances Algal Ftah Potential Proble• • EPA A~fent Uatar Qualfty *• State Standard Project Bloou Kflls Areaa Criteria: Exceedances Exceedances

standing Bear lake, lioacc~latlon INFLOWS: none Identified. IIFLOVS: fecal cotffor• Papillion Creek of Mercury and bacteria. Reaervofr Chlordane REIERVOIIa arsenic, pH, ..nganese, Nebraaka Bacterial dflsotved oaygen, ..rcury, lead, RESERVOIR: dllaolved oxygen, Tributary Yes No Conta•lnatfon copper. pi, ..rcury, fecal collfor• Algal Toxins IMcterla. Alachlor RElEASES: arsenic, ..rcury, Iron, Si•azfne ..nganesa. RELEASES: •ercury •

Site 20, Btoacc~tatlon INFLOWS: ar1enlc, Iron, ..nganase, IIFLOUI: fecal colffor• Papillion Creek of Mercury and nitrate, cyanide. bacteria. Reservoir Chlordane Nebraska Bacterial RESERVOIR: dlasolved oxygen, Tributary Yea No Conta•lnstlon RESERVOIR: arsenic, ..rcury, zinc, fecal collfor• bacteria, Algal.Toxlns dissolved oxygen, ..nganase, lead. Mrcury. RELEASES: unmeasured. RELEASES: unMe8sured.

N Site 18, Bioaccu.ulatlon INFLOWS: arsenic, cyanide, Iron, INFLOWS: fecal collfor• 0 Paptlllon Creek of Mercury and Mnganese. bacteria. Reservoir Chlordane Nebraska Bacterial RESERVOIR: not l•pounded. ·Tributary No No Contamination RESERVOIR: not i 11p0unded. Algal Toxins RELEASE SITE: fecal cotlfor• bacteria. RELEASE SITE: arsenic, Iron, •anganese, cyanide.

* This column contains pesticides detected In project waters which are not covered by state or federal standards. ** See the 1989 Water Quality Management Progra• Annual Report for 1989 Exceedances

------Holmes Park Lake, in Lincoln, Nebraska; and over the service spillway at Cold Brook Dam near Hot Springs, South Dakota.

VIII. WATER CONTROL MANUALS. Funds for revising and/or preparation of Water Control Manuals was deleted in both the FY90 and FY91 Civil Works Appropriation Bills. The District is allocating limited funds from other functions to work on high priority manuals. Work is expected to be completed in early FY91 on the Papillion Creek Preliminary Manual. Five projects do not have final manuals. They are Chatfield, Bear Creek, Canyon Ferry, Glendo and Papillion Creek. In addition many of the instructions to dam tenders and forecast equations, that are included in the manuals, need updating. Table 7 outlines the work priorities for the reservoir regulation activities.

IX. DATA COLLECTION PROGRAM AND PROCEDURES.

,, A. Collection of Water Control Data. Data from hydrologic gages for water control management is obtained from various sources including contract observers, project offices, National Weather Service, Geological Survey, Bureau of Reclamation and Satellite Data Collection Platforms (DCPs). The National Weather Service provides current weather conditions, 3-day forecasts I and precipitation and snowfall reports along with current river levels, river I level forecasts, and flood forecasts. Since March 1986, this service, called "Datacol", has been retrieved from a NWS computer in Kansas City. Additional weather analyses and forecasts are received through a Digital Facsimile Network via SISCORP Corporation. Products prepared by the National Meteorological Center (Camp Springs, Maryland) and other meteorological offices of the National Weather Service are received via a satellite/microwave transmission network. This weather facsimile service displays real-time surface maps, rainfall, temperature and other maps pertinent to forecasting.

Another real- time forecasting tool used to monitor meteorologic conditions is a weather radar monitor purchased from Kavouras, Inc. Instant radar echoes are received from approximately 100 radar sites conus-wide by telephone. The user has a choice of echo ranges from each site that are 60, 120, 180, or 240 nautical mile radii. The real-time weather patterns are displayed on a 19-inch color monitor that is coded in six colors, each designating a level of precipitation intensity. The radar monitor is used in conjunction with other forecasting tools for precipitation forecasting and to track intense rainfall movement for reservoir regulation. This system is particularly beneficial for monitoring those projects with short peaking times and for alerting and advising other District elements of threatening meteorologic conditions. A recent software package upgrade allows display of real-time satellite images of cloud cover across the continental United States on a dedicated microcomputer. Images are transferred across telephone lines. The addition of this package enables continuous monitoring frontal movement and weather patterns that could produce heavy precipitation.

The primary Corps of Engineers/Missouri River Division data archiving system is called the Missouri River Automated Data System (MRADS). The system resides in the Corps of Engineers/North Pacific Division AMDAHL mainframe computer. The data base contains river and reservoir data from throughout the

21 WORK PRIORITIES

FINAL RESERVOIR REGULATION MANUALS

PRIORITY PROJECT REMARKS

1 Papio Final Draft schedule to MRD 22 May 91 2 Chatfield Start scheduled 2 Jan 91 3 Bear Creek 4 Glendo 5 canyon Ferry 6 Audubon

PRIORITY PROJECT REMARKS

1 Pactola To reflect raise in dam and widening of spillway 2 Coldb rook To reflect changed outlet pipe and line from stilling basin to Larvie Lake 3 Shadehill To reflect changed outlet works

WAXER AGRIEMENT~

PRIORITY PROJECT REMARKS

1 Cherry Creek Pending proposed change in recreation pool level INSTRUCTION TO DAM TINDERS

PRIORITY PROJECT REMARKS

1 Heart B

VOLUME FORECAST PRIORITY PROJECT REMARKS

1 Clark Canyon Needs update to reflect change in availability SNOTEL data 2 Yellowtail Same 3 Glendo Same 4 Tiber Same 5 Boysen same 6 Canyon Ferry Same

22 basin and is used extensively for various reservoir regulation activities, such as bulletins, forecasting, graphics and archiving. The MRADS is an efficient network to obtain and distribute data to all water control users.

B. Automated Remote Sensors. State-of-the-art, remote site, satellite data transmissions are utilized for water control management. Satellite collection equipment being used by the District was purchased from Sutron • Corporation. The equipment was and is installed and maintained by Section l personnel and/or by contract. Currently, there are 22 data collection platforms (DCPs) in Montana, 4 in Wyoming, 21 in Colorado, 13 in North Dakota, 18 in South Dakota, 37 in Nebraska and 15 in Iowa for a total of 132 sites with 2 additional sites proposed for 1990.

The DCPs in the District transmit real-time river and reservoir levels, precipitation, evaporation, piezometer levels, wind, water and air temperature data. The hourly data collected by these remote sensors is transmitted to two ground receiving sites located in Omaha, Nebraska (Corps of Engineers) and Boise, Idaho (Bureau of Reclamation). This information is currently transmitted via GOES-west and GOES-central satellites located at 135 degrees west longitude and 98-108 degrees west longitude, respectively. The two ground stations, after receiving the satellite transmissions, send the data by land lines to the MRADS data base in Portland, Oregon. Once the data is entered in the data base it is available for use by water control personnel through office terminals. The District can also interrogate approximately 80 telemark sensors from any telephone. These remote sensors have been installed by the Corps of Engineers, Geological Survey and National Weather Service at Geological Survey and Corps of Engineers stream gaging stations.

Vandalism continues to be a problem at the gaging stations. The most frequently experienced destruction or theft occurs to the solar panels and antennas.

C. Cooperative Hydrologic Programs. Funding for the Omaha District's stream gaging activities is furnished through two programs. The Cooperative Stream Gaging (FC-33) program provides support to seven Geological Survey Districts. The districts are Colorado, Iowa, Montana, Nebraska, North Dakota, South Dakota and Wyoming. Collection and publication of data such as stage, discharge, sediment, water quality and ground water records are the primary functions of this program. The cooperative program also provides funding for DCP and telemark maintenance. The National Weather Service Reporting Network (FC-50) program provides financial support for the collection of data from 40 gaging stations within six river district offices. Formerly operated by the Corps of Engineers these stations are required for reservoir regulation. The stations are in addition to the regular National Weather Service reporting stations.

D. Water Quality. The Omaha District Water Quality Unit conducts sampling and analysis of physical, chemical and biological parameters on reservoirs in the Omaha District. Projects are normally sampled six times per year by in-house personnel, area personnel or under contract. Occasional surveys and special investigations on all projects are conducted as necessary to identify or resolve specific water quality problems.

23 In-house personnel sample the Papillion Creek and Salt Creek reservoirs. Bowman-Haley, Coldbrook, Chatfield, Bear Creek, Cherry Creek, Lake Audubon, Lake Pocasse, Lake Yankton Pipestem and the Missouri River main stem reservoirs are sampled by area personnel or under contract. Periodic sampling at Cottonwood Springs reservoir has ceased since this project currently impounds very little water.

Inflows and releases are sampled by area or in-house personnel at all tributary projects. Inflows and releases of main stem projects are sampled by area personnel or under contract by the USGS. • ~ Continual remote monitoring of dissolved oxygen and temperature and periodic monitoring of pH and conductivity is conducted at the releases of all l main stem reservoirs. I E. Sediment. All suspended sediment samples collected in the Omaha District are obtained by the Geological Survey under the Cooperative Stream Gaging Agreement. Complete sedimentation surveys of small reservoir projects are made at approximately 10-year intervals. These include aggradation surveys to update water volume storage and sediment accumulation values, monitor headwater disposition and lake shoreline erosion; and degradation surveys to monitor downstre~ channel changes. Complete resurveys were made of Pipestem and Stagecoach reservoirs this year. Table 8, shows the sedimentation rates at some of the reservoirs.

X. FLOODING.

A. 1111 ~ Trikutaxy Flooding. Nebraska ~ l!ll ~

l. G~meral. The Salt Creek basin drainage area encompasses approximately 1,645 square miles with more than twenty tributary creeks. Salt Creek headwaters start approximately 30 miles south of Lincoln and joins the Platte River approximately 3 miles downstream of Ashland. In early September, several watersheds near Lincoln, including Beal Slough, Antelope Creek, Dead Man's Run and Stevens Creek, flooded.

2. Preflood Conditions. Prior to the storms in early September, the basin had received very little precipitation. The long term Palmer index of August 26, 1989 showed extreme drought conditions for the basin and a moisture deficiency of 4.3 inches.

3. ~ Event. A line of heavy thunderstorms entered Lincoln from the southwest, about 0700, September 8, 1989, causing extremely heavy rain in southeast Lincoln and communities to the south and east. The heaviest rains in the Lincoln area were reported over the Antelope Creek and Beal Slough basins. A second line of heavy thunderstorms moved over the city about 1700. The heaviest precipitation fell to the northeast of the city, but at least an additional inch or two were reported in most areas of Lincoln from the second storm.

24 TABLE 8.

Dllh1 District Tributary Lakes RestrVOir Stor-ee .a Sedi..,ution Rat•

Origin~~l cap.city in 1,000 Ac...-Feet cur...,t cap.city in 1,000 Acre·Feet tapecity Reduced in 1,000 Acre•Feet Capeci ty Red.lced in Pltf"Centage Sedi-.,t Depletion Rate in Ac .. ft/Yr

5urvoy Flood CcnHt'Vo 11-tiW Irwctive Year Flood Conserv. Inective flood ConHN. rn.ct i w Oooign Flood CclnHn'. lrw:tive Project -- flood canurv. Yoor Pool Pool Pool ToUL Ynr Pool Pool Pool Total Elopood Pool Pool Pool Total Pool Pool Pool Total Rate Pool Pool Pool

Gl., Clnlingio• 1976 14.02 3.71 (0.00) 17.73 1987 13.90 3.26 (0.00) 17.16 11 0.12 0.45 0.57 0.86 12.13 3.21 0.01 0.04 0.00 0.05 0.25 0.30 0.01 0.04 sundlnv -· 1976 3.64 1.50 (0.00) 5.14 19114 3.59 1.25 (0.00) 4.84 a o.os 1.37 16.67 5.84 0.03 0.00 Popio 18 19115 7.59 3.47 (0.001 11.06 0.00 Wlllnpolln 19114 6.08 2.n (0.001 8.80 0.00 Chatftold 19111 Z04.74 26.69 (0.001 231.43 19114 206.94 28.15 (0.001 235.09 3 ·2.20 ·1.46 ·3.66 ·0.73 ·0.49 0.00 ·1.22 Olorry Crool< 1957 81.38 14.40 (0.001 95.78 1988 79.32 12.81 (0.001 92.13 31 2.06 1.59 3.65 2.53 11.04 3.81 0.07 0.05 0.00 0.12 0.39 - CrHit 19111 28.83 1.91 0.07 30.81 19114 28.76 1.86 0.07 30.69 3 0.07 0.05 0.00 0.12 0.24 2.62 0.02 0.02 0.00 0.04 --thlloy 1969 73.20 15.50 4.28 92.98 19114 n.n 15.46 3.31 91.49 15 0.48 0.04 0.97 1.49 0.66 0.26 22.66 1.60 0.03 0.00 0.06 0.10 Pfpest• .. 1973 137.01 9.59 o.28 146.88 0.00 Ollw Crool< - 1964 3.911 (0.00) 1.49 5.47 o.oo llue St• 1964 7.11 0.40 2.67 10.18 19114 7.11 0.39 2.30 9.80 20 o.oo 0.01 0.37 0.38 2.50 13.86 3.73 0.00 0.00 0.02 0.02 Wegan Trein.,.. 1963 6.79 0.83 1.66· 9.28 o.oo ,._.,...,_ 1964 4.70 (0.001 1.94 6.64 0.00 Yrioo Hill 1966 5.87 0.60 1.32 7.79 19115 5.85 0.59 1.12 7.56 19 0.02 0.01 0.20 0.23 0.34 1.67 15.15 2.95 o.oo 0.00 0.01 0.01 conoot... 1964 8.03 (0.00) 2.61 10.64 0.00 Tvtn Laa. ** 1966 5.25 0.81 2.02 8.08 o.oo 1966 20.33 ~0.001 8.83 29.16 19111 20.29 (0.001 7.83 28.12 15 0.04 1.00 1.04 0.20 11.33 3.57 0.00 0.00 0.07 0.07 Hol_ ... 1963 5.77 0.25 0.62 6.64 1963 5.119 0.27 0.63 6.79 ·0.12 ·0.02 ·0.01 ·0.15 -Brandied Oolk - 1967 71.57 12.74 13.25 97.56 o.oo Cold...... 1954 6.68 0.52 (0.001 7.20 0.00 Cottlll"lld.- 1974 7.73 0.25 0.41 8.39 0.00

IN'W in 1911 Chotflold -· .. Vol- ..,_ oro ••i-•. Detollod ..,.lata to be-'- fY9Q. - llot.. LaY otonae 1-- to -ion of 19114 -·

TABLE B The most extreme rainfall and run-off occurred near Holmes Lake, (Salt Creek Dam #17) on Antelope Creek. Rainfall apparently exceeded 11 inches in a few isolated locations upstream of the dam, during a 24 hour period. A wide area reported 8 inches or more from the two storms. A new record pool elevation of 1249.1 was reached on Holmes Lake early on 9 September 1989. This was the highest stage recorded for Dam 17 for the period 1962-1989. Point rainfall amounts in parts of the Antelope Creek and Beal Slough Basin greatly exceeded the 100-year 6 hour rainfall of 5.19 inches, as given in TP-40. Fortunately, most of the extreme rainfall fell above Holmes Lake and covered only a fraction of the unregulated urban watersheds.

Rainfall amounts from the flood-producing morning storm varied in the Lincoln area. Flooding from the morning storm was reported on Beal Slough, Antelope Creek and the upper part of Dead Man's Run. Stevens Creek also flooded. In addition to the upper Antelope Creek and Beal Slough watersheds which received more than 6 inches, parts of the South Central Lincoln reported over 5 inches. Lesser amounts ranging down to 2. 5 to 3. 5 inches were reported between the two areas of heavy rain. Most of the Dead Man's Run Watershed received rainfall amounts of 2. 5 to 5 inches, with the .. heavier amounts in the upper watershed. The least rain was received in the northwest part of Lincoln, where the morning storm dumped 1.5 to 2.5 inches of rain.

Antelope Creek exceeded bankfull, briefly, during the morning storm at the 40th Street bridge. Analysis of 16 years record at the 48th Street crest stage the flood was about a 20-year event in that reach. Below 27th Street on Antelope Creek a discharge of 2,750 cfs was computed. The discharge remained within the bank during the storm. The bankfull discharge was estimated to be about 6,2000 cfs, in that immediate reach. Based upon a gage height estimate at the old 27th Street gage, crest stage gage of 12.1 feet was reached. A SWMM model of the basin developed a discharge of 2,750 cfs near 27th Street, which corresponds to a 20-year flood at the gage.

A peak discharge of 3,100 cfs was computed for Dead Man's Run below the 38th Street (above Leighton Avenue) on East Campus. The flood remained within it's banks in this reach. The bankfull discharge is estimated to be 6,850 cfs in the slope area reach. According to a recent SWMM model of Dead Man's Run, a discharge of 3,1000 c.f.s. will occur every 5 to 10 years. The SWMM model produced a peak discharge for that reach of 3,500 c.f.s. with the bucket survey as input.

A peak discharge of 2, 250 cfs was computed for Beal Slough above 48th Street. The stream was out of bank in that area and flood damages were reported from upstream of 56th Street to the mouth. According to an old study, a discharge of 2,250 cfs would correspond to about a 20-year flood.

1. General. The Perry Creek basin includes 65 square miles and is located north and west of Sioux City. The basin starts about 20 miles n~rthwest of Sioux City and enters the Missouri River at Sioux City. A series

.., of storms hit eastern Nebraska and western Iowa in May 1990, which caused some local flooding throughout the area. The Perry Creek basin was particularly hard hit by rain. Also, the basin is heavily wooded, which added debris to the channel, reducing capacity and increasing the likelihood of flooding.

2. Preflood Conditions. Through early May, the Sioux City area was in a severe drought region as defined by the Long Term Palmer Drought Severity Index. This condition resulted from several years of below normal precipitation. By mid-May, weather patterns that had caused flooding in the south shifted northward with the subtropical jet stream. Rainfall amounts in the preceding week were light to moderate, but had served to partially saturate the topsoil. The heaviest rain preceding the flood occurred on 15 and 16 May when 0.54 inches of rain was reported at the Airport. Amounts of 1 to 2 inches were reported in parts of the Perry Creek basin from that storm.

3. Flood Event. During the morning of May 18th, a surface low organized in southeast Wyoming along with a low pressure trough that was oriented along an east-west line through Wyoming and western Nebraska. Driven by moderately strong winds aloft (45-50 kts), the low moved east-northeastward toward northeast Nebraska. By noon on Friday, a warm front had formed ahead of the storm center and was located across northern Nebraska and Iowa.

By late Friday night, the storm center deepened and moved towards the Sioux City area. Severe thunderstorms formed in western Nebraska late Friday afternoon and swept eastward ahead of the advancing storm center. By late Friday, conditions were ideal for heavy rains in eastern Nebraska and western Iowa.

Existing thunderstorms grew rapidly as they moved into the Sioux City area. From data collected during a rainfall "bucket survey", which was conducted by the Omaha District on 21 May 1990, it appears that two strong thunderstorm cells intensified over the city and moved northeastward, covering I, most of the basin with extremely heavy rain from 2100 to Midnight on 18 May.

Rainfall amounts in the basin ranged from under 3 inches at the extreme upstream end of the basin near Brunsville to around 6 inches in the East Central part of the basin West of Hinton. Amounts of 3 to over 5 inches were reported in most of Sioux City by 0700 19 May. Rainfall at the Airport, located 6 miles south of the basin was 1.89 inches during the storm.

The average basin rainfall was about 4.6 inches. This was computed from the bucket survey conducted on 21 May 1990. Over 40 rainfall measurements were included from a wide area of Woodbury and Plymouth Counties. An isohyetal map, which is shown on Figure 3, was prepared from the data obtained from the bucket survey.

The duration of the storm was estimated to be approximately 10 hours from information supplied by the Sioux City office of the National Weather Service on 21 May. According to data collected at the Airport, the storm began about 2000 18 May and ended about 0620 19 May. The peak rainfall intensity occurred about 2400 18 May.

27 tt!JIII:P.:I ; ".2 2" ·=~~ ...... ,.!

.. ··.···. ~~· -~·

4' ,...,...... :.: , .... ~ "':':t ,,

4' 3 ... 2'

3' 2'

I SIOUX I-29 I I

STORM OF 18-19~ MAY 1990 ISOHYETAL r~AP PERRY CREEK BASIN SIOUX CITY~ IO\v'A

X-1 28 Figure 3 An analysis of the depth-duration characteristics of the storm was made for comparison with hypothetical storms of various return periods.

The total rainfall which occurred over the Perry Creek basin during the 18-19 May 1990 storm exceeded the 50-year frequency event. However, the peak 1-hour intensity was less severe, approximately a 10-year event. It should be noted that the distribution of the storm was based on information obtained during the bucket survey, since no recording rainfall data were available to adequately define the storm distribution. This exceeded the 1.89 inches recorded at the Airport in the storm of 18-19 May. 'While no bucket survey was conducted for the second storm, it is likely that the total reported at the Airport was representative of rainfall amounts in the Perry Creek Basin.

Similar weather conditions caused additional flooding on May 23rd. A series of low pressure troughs moved across western Iowa between Tuesday afternoon and Wednesday morning. Feeding on locally available moisture and supported by moisture from the south at the 850 mb level, isolated heavy thunderstorms developed Tuesday night. Sioux City had the misfortune to receive the heaviest of those storms reported at official gages. The rainfall total at 0600 23 May was 2.10 inches at the airport. This exceeded the 1.89 inches recorded at the airport in the storm of 18-19 May. 'While no bucket survey was conducted for the second storm, it is likely that the total reported at the airport was representative of rainfall amounts in the Perry Creek Basin.

Antecedent moisture conditions were more favorable to flooding on 22 May than they were on 18 May. The soil profile was saturated and depression storage was nearly full from the flood 4 days earlier. Once the rainfall concentrated as run-off in Perry Creek, overbank flows were enhanced by debris from the earlier storm that clogged the channel.

5. Flood Stages Flood stages upstream of Stone Park Blvd. were in the 10 to 50-year range while from Stone Park Blvd. to Plum Creek flood stages exceeded the 100-year flood profile. Downstream of 26th Street, flood stages were near the 10-year flood profile. It appears that extremely high flood stages between Stone Park Blvd. and Plum Creek may have been caused by a debris blockage of the bridge openings at Stone Park Blvd. and Hamilton Street. The lower flood stages (10-year level) downstream of 26th Street were caused by the fact that flood flows entered the right bank floodplain near this location and the storage effect of the floodplain attenuated the flow and reduced the downstream peak discharges. Flows measured at the USGS recorder gage site ranged from 6 cfs on May 18 to 8670 cfs on the morning of May 10. The peak flow was at 0330 on May 19.

C. Eastern Nebraska and Western Iowa ~ June 1990

(Excerpts of the National Weather Service Monthly Report of River and Flood Conditions Report, July 10, 1990 were in this summary.)

29 1. General. Widespread rains and flooding occurred June 12 through the 17th in eastern Nebraska. Heavy rains caused flooding in Platte Center Nebraska, and near Neligh, Ewing, Rogers and Madison. Union Creek, Shell Creek, Maple Creek, Pebble Creek and many smaller streams were flooding. The counties of Platte, Madison, Colfax, Stanton, Dodge and Cuming were hardest hit by flooding. The lower Nishnabotna basin in Iowa was also flooded.

2. Preflood Conditions. Prior to the June storms, most of Nebraska was at normal to moderate moisture conditions according to the long term Palmer Index. The month of June was the 13th wettest June of record for the state of Nebraska. The average precipitation was 3.74 inches--some 0.91 inches above the 2.83 inch normal. The eastern third of the state was quite wet with parts of the northeast section receiving up to 8 to 12 inches.

The heaviest rains and the widespread flooding mainly occurred in the second week of June--during the 12th through the 17th days--in eastern Nebraska and western Iowa. Persistent subtropical moisture triggered by a stagnant weather front set off a series of damaging rainstorms during that week.

On the night of the 12th, some 1 to 4 inches fell in northeast Nebraska saturating the soils and priming the rivers and streams for heavy rains that came two days later.

3. ll22d Events. On the night of the 14th, widespread heavy rains fell in northeast, central and southeast sections of the state. Flash flooding from 4 to 5 inches of intense rains flooded one third of the homes and businesses in the small town of Platte Center, and washed away 15-20 cars and many empty ammonia tanks off the streets of nearby Lindsay and into the local creeks--both towns in northeast Nebraska. A three county area from near Beatrice to Fairbury to Friend in southeast Nebraska were flooded the night of the 14th when 3 to nearly 6 inches fell. In addition, 3 to 5 inch rains fell in the Grand Island to St. Paul area and in the Neligh to Ewing area.

On the very next night of the 15th, heavy rains of 2 to 3 inches fell again in the already flooding northeast sections of the state. A pocket of nearly 6 inches fell in the Madison area bringing the Union Creek well out of banks. Shell Creek, Maple Creek, Pebble Creek and many smaller streams all were flooding that night. Many county roads and some state highways closed due to flooding.

A third consecutive storm hit the northeast rivers of the state on the night of the 16th when another 1 to 2 inches fell. This aggravated the flooding rivers and brought the flooding to the moderate to severe level in Platte, Madison, Colfax, Stanton, Dodge, and Cuming Counties. Many rural bridges were washed out by the floodwaters and made impassable. Agricultural damages from soil erosion were quite severe. Widespread losses to young row crops resulted in the flooded areas, as well. By the 17th and 18th, the floodwaters crested in the larger rivers of northeast and east central Nebraska. The small town of Rogers along the lower reaches of Shell Creek in Colfax County flooded to a depth of 2 to 3

30 feet for 2 days. The communi t~r of King's Lake on the lower reaches of the Elkhorn River took on 1 to 2 feet of floodwaters, forcing the evacuation of around 150 people. On the Missouri River, many riverfront cabins, marinas and bottomland farms flooded form just upstream of Omaha to below Rulo in the southeast corner of the state. Around 15 to 30 homes in the !skies' and Holub's riverfront caught 2 to 4 feet deep floodwaters from the swollen Missouri River. On the afternoon of the 17th, flooding was occurring on the Nishnabotna River where between 3 and 8 inches of precipitation had occurred between June 12 and June 20th.

The flooding in northeast Nebraska was the most severe since the June 1984 floods. The Shell Creek floods were the greatest since the record floods on 1950. The Pebble Creek flood at Scribner exceeded the previous record flood set in 1984, and, the Union Creek at Madison set a record high stage.

Table 9 shows gage height information at selected sites and Table 10 shows precipitation.

31 TABLE 9. Pertinent Gaging Locations

Recurrence Preliminary Estimated Station Internal (Years) Date Peak/Flood Stage Discharge(cfs)

NEBRASKA: Elkhorn River Norfolk 6/16/90 9.41/10 West Point 10 6/17/90 14.17/2 28,000 Hooper 6/17/90 19.2/14 Waterloo 15 6/19/90 17.23/15 35,700 Union Creek Madison 100 6/16/90 28.57/20 30,000 Maple Creek Nickerson 2NW 50 6/18/90 16.3/12 11,600 Pebble Creek Scribner 50 6/17/90 23.90/13 22,700 Shell Creek Columbus 8NE 100 6/17/90 22.76/20 8,000 Logan Creek Uehling 6/17/90 * E 15.83/16 Platte River North Bend 6/17/90 7.68/8 Louisville 6/17/90 9.13/9 68,000 Beaver Creek Genoa 6/17/90 7.27/9 Missouri River Omaha 6/17/90 26.9/29 Nebraska City 6/19/90 20.6/18 Brownville 6/20/90 36.3/32 Rulo 6/20/90 20.3/17 Little Blue River Fairbury 6/15/90 12.1/10 Big Blue River Beatrice 6/15/90 * E 19.0/16 Barneston 6/15/90 24.9/20 IOWA: West Nishnabotna River Hancock 6/17/90 18.5/14 Randolf 6/18/90 19.6/19 Nishnabotna Hamburg 6/18/90 27.0/16 Floyd River Alton 6/28/90 14.28/12 Little Sioux River Spencer 6/20/90 10.15/10 Turin 6/17/90 22.53/20 Boyer River Logan 6/17/90 21.50/19

* E - estimated stage

-~~-- ---~--- --~----~----- '. TABLE 10. PRECIPITATION SUMMARY JUNE 10 - JUNE 17

LOCATION PRECIPITATION (INCHES)

NEBRASKA: West Point 4.36 Norfolk 4.27 Grand Island 8.27 Tarnov 9.84 Colwnbus 6.47 Hastings 4.89 Beatrice 5.68 Fairbury 6.39 Aurora 5.50 Haring ton 5.07 Oakdale 5.39 Wakefield 4.13

IOWA: (JUNE 12 - JUNE 20) Little Sioux 8.44 Dennison 7.60 Turin 7.98 Adair 4.70 Clarinda 4.63 Hancock 3.07 Shenandoah 4.10

D. Eastern Nebraska and Western Iowa ~ July 1990

(Excerpts of the National Weather Service Monthly Report, Aug 8, 1990 were used in this summary.)

1. General. Widespread storms again hit western Iowa and eastern Nebraska in mid July. Counties which were hit hardest were Adams, Clay, Fillmore and Saline in south central and south eastern Nebraska, and Mills and Fremont counties in Iowa.

2. Preflood Conditions. A series of rain storms beginning in May, broke the drought of the previous several years and returned hydrologic conditions to near normal. According to the 21 July Drought Severity Map (Long-Term Palmer) most of the region was neither in a drought nor considered moist. Antecedent conditions were normal or average.

3. Flood Event.

a. Southwest Iowa: Rainfall amounts from the storm were extremely heavy, ranging up to 15 inches in Fremont County, Iowa. Amounts of over 10 inches in 24 hours were reported over a large area. These extremely large 24-hour rainfall totals compare to 100-year 24-hour point rainfall values of about 6.8 inches for southwest Iowa was given in TP-40. According to HMR 53, the 10 square mile PMP for a 24 hour period in July and August is

33 32" for that region. Thus, rainfall amounts in Fremont County of western Iowa nearly equaled 1/2 of the PMP during the storms of 25 July 1990. An unofficial amount of 12.8 inches was reported at Imogene. Flooding on Skunk Creek forced the evacuation of 35 Thurman residents on 25 July. In the Nishnabotna basin, several roads were closed, and large areas of lowlands were flooded. Many homes experienced basement flooding in Hamburg, Riverton, Randolph and Oakland. Nishnabotna at Hamburg crested on 26 July @ 28.03 feet slightly below the record stage of 28.05 set in 1987.

Rainfall data were collected by bucket surveys conducted 26 and 27 July by CEMRO-ED-H. Additional data were obtained from Omaha, Lincoln and Council Bluffs newspapers.

b. Eastern Nebraska. Precipitation varied widely over the state of Nebraska in the month of July. The east central region was the wettest with an average of 6.5 inches, and the central and south central the driest with less than 2 inches. Overall, the state averaged 3.4 inches-- normal is 2.8 inches. This total was the wettest July since 1981, and the 13th wettest July of record.

There were only two damaging rainstorms during the month. The first storm occurred the night of the 19th. A narrow band of heavy rains fell in northeast part of the state. A 2-4 inch packet of rains fell from around Emerson to Sioux City, Iowa where some street and small stream flooding took place. On that same night in south central into east central Nebraska more general heavy rains fell. At least 1-2 inch rains fell from Minden to Lincoln. Four to 5 inches in the Hastings area caused urban flooding to the town, and 6-9 inches in northern Clay and northwest Fillmore counties brought flash flooding to Sutton from the flooding School Creek. Some 10-15 homes and businesses caught up to 3 feet of flooding to Sutton. Harvard received 6 inches of rains and some street flooding, as well. Many county roads and State Highways's 14 and 6 in the Sutton area wer~ closed due to flood waters for 2 days. Then, in the ensuing several days, flooding of lowlands took place along the West Fork Big Blue river downstream to Dorchester.

The second damaging rainstorm of July hit the east central area on the night of the 25th. Three to nearly 10 inches fell in the area from Flair to Polk to Crete to Nebraska City. The heaviest rains fell in the Salt Creek and Weeping Water Creek watersheds. Moderate to even major flooding took place along the middle and lower reaches of the Salt Creek. Street flooding happened in the city of Lincoln where 4 to 6 inches fell. Extensive flooding happened in the entire Weeping Water Creek where 5-8 inches were common. Urban flooding was felt in the low lying areas of Nehawka and Union, and State Highways's 34 and 77 near Union were closed due to flooding.

The Missouri River from around Plattsmouth to below Rulo came out of banks affecting mainly agricultural lowlands as run-off from southwest Iowa and east central Nebraska rivers contributed heavy flood flows in the latter part of the month.

. ' I J,\ TABLE 11. SELECTED STAGE REPORTS

Preliminary Peak/Flood Estimated Station Stage ilil Discharge(cfs)

IOWA Nishnabotna Hamburg 7/27 28.03/16 31,900 West Nishnabotna Randolph 7/26 23.50/19 27,200 East Nishnabotna Red Oak 7/26 12.85/18 4,960

NEBRASKA I Salt Creek Lincoln 7/26 20.43/20.5 19,200 • Greenwood 7/26 25.50/20 38,900 Weeping Water Creek Union 7/26 29.20/25 25,400 Ithaca 7/26 19.54/19 3,940 Missouri River Nebraska City 7/26 18.42/18 89,600 Rulo 7/27 18.77/17 98,700

XI. WATER CONTROL INITIATIVES.

During the report period, studies by the Water Control Section and others included the following:

A. Missouri River Division Water Control Data System Master Plan. Upgrading of the hardware and software systems for use with the Missouri River Division ground receive site and for the NPD AMDAHL computer continue to improve and expand data collection and management procedures in the Water Control Data System. The MRD Master Plan for Water Control Data Collection and Management System is completed and has been submitted to HQUSACE for approval. The plan calls for a microcomputer based UNIX operating system in an ethernet network environment.

A Water Control Task Group was formed in April 1987 within the Missouri River Division. The task group consists of representatives from the Missouri River Division Information Management Office, the Reservoir Control Center, the Kansas City District Water Control Section and the Omaha District Water Control Section. Meetings of the group act as a forum for exchanging information and a means of providing district input. This task group is charged with software concerns. An important function of the task group is to demonstrate and disseminate new developments in software. Meetings are held once every two months on the average. Major items covered this year were the movement of software on the AMDAHL mainframe to the microcomputer and the

35 implementation of the Platte River forecasting model. Information acquired through the Water Control Task Group regarding updated software has led to improvements in dealing with Section tasks.

At the end of this reporting period the office had 12 microcomputers. The section continues to utilize the Hydrologic Engineering Branch Network for storage and transfers of data files. A Xerox color ink jet printer purchased for use with the KAVOURAS radar system makes available hard copy color radar maps that can be used for displays, reports and for the study of unusual storm events throughout the District. The section continues to pursue state of the art equipment and software information in the areas of data base use, including data collection, screening and transfer, and graphics type applications.

B. Denver Model. The Denver Area Real-Time System (DARTS) has been converted from the North Pacific Division AMDAHL computer to operate on a 386 microcomputer. The remaining task involves completing the interface between I the model and the necessary input data. Trial runs will be conducted prior to the spring run-off season of 1991. • C. ll!&h Pool Levels. A tabulation of the number of cases that the exclusive flood control zones in the 35 Omaha District tributary reservoirs have been filled to 25, 50, 75 and 100 percent is shown on Table 12. Most of the near capacity pools occurred at the Section 7 Bureau of Reclamation projects.

XII. Ill& Applications. During the period of this report, 6 applications for preliminary permits, licenses or exemption from licensing were made to the Federal Energy Regulatory Commission by various entities for studies in connection with new or existing hydropower facilities within the Omaha District. These applications were reviewed and comments were prepared by the District on the impact of the proposed plant on the responsibilities of the Corps of Engineers.

36 TABLE 12. UTILI~\TION OF EXCLUSIVE FLOOD STORAGE ZONE OMAHA DISTRICT TRIBUTARY PROJECT

TOTAL NUMBER PERCENT OF FLOOD CONTROL STORAGE OF TRIBUTARY YEAR PROJECTS 25% OR MORE 50% OR MORE 75% OR MORE 100% OR MORE

1967 26 3 2 2 0 1968 27 0 0 0 0 1969 27 1 0 0 0 1970 28 2 2 0 0

1971 28 2 1 0 0 1972 28 1 0 0 0 1973 28 6 2 1 0 1974 31 1 1 0 0 1975 32 6 2 1 1 1976 32 2 1 0 0 1977 32 0 0 0 0 1978 33 5 1 0 0 1979 33 1 0 0 0 1980 33 2 1 0 0

1981 33 2 1 1 0 1982 33 2 1 0 0 1983 34 5 1 1 0 1984 35 7 2 1 1 1985 35 0 0 0 0 1986 35 5 0 0 0 1987 35 3 0 0 0 1988 35 0 0 0 0 1989 35 0 0 0 0 1990 35 0 0 0 0

TOTAL 56 18 7 2

100% OR MORE EVENTS: 1975 - Canyon Ferry Reservoir 1984 - Clark Canyon Reservoir

37 XIII. TiAINING ~ METHQDS. During the period of this report, employees in the Section attended the courses listed below:

1. Real Time Water Control Davis, CA 76 hrs Dec 89

2. Streambank Protection Vicksburg, MS 36 hrs Apr 90

3. Safety & Health for Kennesaw, GA 40 hrs Aug 90 Hazardous Waste Sites

- and - _. of this Section conducted a training and troubleshooting class on~ operation and maintenance of DCPs (Data Collection Platforms) for representatives of the United States Geological Survey (USGS). The class was held in Omaha in August 1990.

On-the-job instruction and training of new employees and existing staff members continues as duties and new techniques require.

XIV. PQSONNEL. The pers.onnel strength of the Water Control Section currently consists of five Hydraulic Engineers, four Hydraulic Engineering Technicians, one Clerk Typist, and one Hydraulic Engineering Technician (Part time college student); a total of 11 personnel.

Effective January 28, 1990 the Section name was officially changed from the Reservoir Regulation Section to the Water Control Section. This change was implemented to more effectively describe the functions of the section and to minimize confusion caused by similarly sounding names of other elements of the Omaha District. An organizational chart for the Omaha District is shown on Figure 5.

. \ ' I ' ~·. MAP OF FLOOD CONTROL DAMS

Appendix 1 -- OMAHA DISTRICT BOUNDARY

0 N

PAPILLION CREEK DAMS (C. E.)

E B R A s

I ~--- 1 I

I SCALE IN MILES 50 0 50 100

LEGEND: (C.E.) CORPS OF ENGINEERS (B.R.) BUREAU OF RECLAMATION FEDERAL TRIBUTARY PROJECTS WITH FLOOD CONTROL STORAGE U.S. ARMY ENGINEER DISTRICT, OMAHA TRI-LAKES DAMS CORPS OF ENGINEERS OMAHA, NEBRASKA (C. E.) REVISED AUGUST 1988 PROJECT DATA SHEETS - TRIBUTARY

(4 Sheets)

Corps of Engineers Dam Salt Creek Basin Dams - C.E. Papillion Creek Basin Dams - C.E. Bureau of Reclamation Dams Subimpoundment Dams (Two) - C.E.

Appendix 2 SUMMARY OF ENGINEERING DATA - FEDERAL RESERVOIRS WITH AUTHORIZED FLOOD CONTROL MISSOURI RIVER TRIBUTARIES - U.S. ENGINEER DISTRICT - OMAHA CORPS OF ENGINEER DAMS

ITEM BULL HOOK SUBJECT BEAR CREEK BOWMAN HALEY CEDAR CANYON CHATFIELD CHERRY CREEK COLO BROOK COTIONWOOD SPRINGS KELLY ROAD PIPESTEM NO SCOTI COULEE

Location of dam 3 m1. S.W of Denver, Colo 6 mi. W of Ha~y. N.D 1 m1 S. ol Havre. Mont 35ml W oiRapidCity.SD 2 mi S of Der.ver. Colo 10m1. S.E. of Denver, Colo 1 mi. N. of Hot Springs, S D 4 5ml. W of Hot Spnngs, S D. lowry A.F B. Denver. Colo 3 m1 N W Jamestown, N.D Rrverand river mtle BearCreek R M 8 N. Fk Grand R M.100 Bull Hook Cr -Scott Coulee Deadman's Gulch Southf>latteRrw R M.321 CherryCreek R.M.114 Cold Brook R M 1 Cottonwood Springs Creek Westerly Creek Pipestem Creek R.M 3 J Oramage area (sq mi.) 236 446 54 04 3,018 386 705 26 594 ReservtHrlength (mt) 0.5atel.5558 25ml aiel. 2755 Normally dry Normally dry 20atel5430 1.5atal5550 1.2ate136465 0.6 m1. atel. 3875 Normally"" dry 5.5atel14424 Locatlono!Damtender At Chatfield Dam Garrison Dam Ft. Pilck Dam Daile Dam Onsne At Chatfield Dam On site AtColdBrookOam Rocky Ml Area Onsrte Traveltime to Missoun River 2 weeks 1 day to Shadehill Dam 2 weeks 8 weeks 7 Max. dtschargeot record 8.600cls July 1896 14,100cfs April1952 _ 440cls August1949 110,000cfs June1965 58,000cfs June1965 8400cls Sept.t938 - 6,080cfs Aprtl1969 8 PrOjectcost(l) $61,700.000 $4,372,200 $1,837,200 $122,600 $101,130.000 $1<1,670,000 $1,571,000 $2,885,000 $232,000 (Original Cost) $9,277,500 DAM AND EMBANKMENT 9 Topol dam- ft. MSL 56895 27940 26133(8H) 261331SCI 35540 5527 56445 3675.0 3955.0 5372.0 53630WestEmb 15075 10 Lengtholdam-lt 5.300-mam2,100-South 5730 1900(8H) 1500(SC.) 1320 13,136 14300 925 1190 4700 4000 11 Heightofdam-tt 179.5-mam65-South 79 73(8H) 53 IS C.) 42 147 141 127 123 32 1075 12 StreamiJed -It MSL 5,510 2715 2540(8H) 25601SCJ 3512 5380 5504 3545 3832 5340 1400 13 Abutment formation Clay, shale. siltstone, sandstone LL!dlow. sandy day, Silty sand Glactal WI. lean day Minneka>Jtanmestone Sandywerburden-DawsonForm Sar.dstone.day.s1tt Sandstone,shale, limestone M1nnekahta limestone Overburden-sandyclay Sandyoverburden-P.Shale 14 Typeofhll Rolled earth Rolled earth Rolled earth Rolled earth Rolled earth Rolled earth Rolled earth Rolled earth Rolledea:th Rolled earth 15 Ftllquantttyincu tds 11.346.1XXl-mam770,000~Sooth 1,750,000 1,300,000 150.000 14,650.000 13.000.000 1.072.000 950,000 200,000 1,990,000 16 Oatealclosure Jul.1977 Aug.1966 Oct 1955 Sep.1959 Aug.1973 Oct 1948 Sept.1952 May 1969 Nov.1953 Rehab1978 Jul1973 17 Dateofmitlalflll(baseF.C.) May 1979 Mar 1969 Jun 1979 March1960 Jun.19ti3(3584.7) May 1974

SPILLWAY 'NotchmBH to2583 3600cfsatel53668 56.200clsatel.1502.8 18 Otschargecapactty-cls 153,500c!satel56845 62,97Dctsatel2789 25,200cfsatel2605 1400cfsate135506 t88,000ctsatel5521.6 38.350clsete156362 80.600clsatel.3667.2 39.600clsatel.3950.3 5362.0 1496.3 Creste~v -It MSL 56670 2777 25930(BH)' 258601SCJ 3545.0 5500.0 56087 36465 3936.0 120 1500 20 Wtdlh-ft 800 650 50 500 67 200 275 Uncontrolled " Ungatedearthchannel 21 Gates, number, size. type Ungatedearthchannel Ungatedearthnotch{2) Ungatedearthchannels Unjlatedrockchannel Ungaledconvergingchute Ungatedearthchannel Ungated sharp crested weir Ungatadbroadwetr Contrele U wall and chute

RESERVOIR ELEV AND AREA 3667.2 279d 13950.0 257a 53668 43a. 15028 7105a 22 Maximum pool 56845 1237a 2789.0 7916a 26050(8H&SC) 3B4a 35506 1S... 5521.6 5972a. 56362(3) 4544a 3936.0 5362.0 3& 1496.3 4754a Topoffloodcootrolpool 5635.5 27770 5131a. 25930(8.H.&SC) 283a 3545.0 1" 5500.0 4764a 5608.7 3101a 3651.4 19& 1585.0 33750 4" 14424 24 Topol multipurpose pool 55580 107a 2754.8 1732a none 5432.0 1422a 55500 "" " "" 30• 14150 25 Topotinacttvepool 5528.0 27400 565• none 35260 "'' "'· 38680 '"' "' " "' STORAGEZONES(Elev-Gapacityl Total-ISH &SC) 3.250AF 5362.0·53668 200AF 1496.3·1502.8 36.850AF 26 Surcllilrge 56355-5684.5 47.350AF 2777.0·2789.0 77.085AF 25930·26050 4000AF 35450-3550.6 74AF 5500-55216 3651.4·3667.2 3,600AF 39360-39500 ~~AF- 122,842AF 3585.0·36514 6,680AF 3875.0·3936.0 7,730AF 53420·53620 360AF 14424·1496.3 137,010AF 27 Floodcontrol 55580·56355 28,757AF 2754.8-27770 72,717AF 25400·2593.0 6500AF 35260·35450 123AF 5432·55000 206. ~~~ 249AF none 1415.0·1442.4 9.590AF 28 Multipuf]lOse 55280-55580 1.857AF 2740.0·2754.8 15,456AF none 5385-5432 28.124AF 55040·55500 12,805AF 3S..8.0·35850 520AF 38680·38750 406AF none 1400.0·1415.0 280AF 29 lnactwe 5510·55280 70AF 27150·27400 3.309AF 35120-35260 13AF 5377-5385 29AF 38320·36680 8.385AF 360AF 146,880AF 30 Grass(topoffloodcontrolpooll 30.684AF 91,482AF 136AF 235,098AF 7.200AF 6500AF 92.126AF

OUTLET WORKS 1-5511.ctrcuiarconduil 1-811 wcularconduit 31 Numberandstze-condut1s 1-711 Circular-upstream 1-1011.c1rcularcondull 1-301n.RCP,Bu11Hook 1-24m CM P 2-th.1611 oval conduit 2-8xt211.ovalcondult 1-6.6711 conduit 1-48m concrete 1-7x10511-downstream t-301n.RCP-Scot1Coulee t-1211.circularcondult 1-Bin supply line 1- J01nCMP 32 Condultlength-11 393ft -Bull Hook 230ft 128011 679.511. 9071! ~Oft. 67511. 169011 34111 Ungateddroptnlet-el.1442.4 ungateddropmlet-el.5558 UngatedGioryHole-eL2754.8 286ft -SconCoulee Ungateddrop1nlet~el.3585 Ungale(ldropmlet-el 3875 33 Number-s1ze-typegates 2-3x61! hydraulic slide 2-30tn.valves-el 27400 1-241n valve. Bull Hook Ungatedmlet-el.3526 2-6x13511.hydraullcslide 5-6x911 -hydraulicsllde 3-12in ga1evalves-al 3548 1-3x31t.gate-el.3868 Ungateddropmlet-el 53584 2-4x711 hydraulteshde 2-tx111 slide-gate on gate 1-30m.lntenorgatevalve 1-241n valve,Sconcoulee 2-2x2.1t slide-gate on gate 2-18ln.bypassga1es t-8tn valve Gated1nlet-el 53420 1-36in valve,t3x3ft.slide 1-30in mteriorslide(13te 1-72m butterfly 250cfsatei.3600.0 34 D1schargecapacity 2,160clsate15667 GloryHole-3206ctsa1el 2789 123cfsat2593-Bu11Hollk 49cfsatel3545 8400cfsatei55000 8100cfsate15598.0 1540cfsate1.36514 56{lcfsate1.3936.0 570cfsatel53620 2,300cfsatel 14963 30 in. ~al~e-140cfsatel 2755 103cfsat2593 Scott Coulee

35 POWER INSTALLATION

(1) Costsareasof9·30·80 November1990 (2) Bowman Haley Spillway equ1pped w1th Fuse Plug (Cres!EievatJon278071t MSL) {3) [JueloupdatedHydrologlcallmprovemenl Assesmenl for Cherry Creek ReservOir, w1th the ma~1mum pool the dam would be overtopped -

SUMMARY OF ENGINEERING DATA - FEDERAL RESERVOIRS WITH AUTHORIZED FLUDD CONTROL MISSOURI RIVER TRIBUTARIES - U.S. ENGINEER DISTRICT - OMAHA PAPILLION CREEK BASIN - NEBRASKA

ITEM SUBJECT DAM N0.11 DAM NO. 16 DAM NO. 18 DAM NO. 20 NO (Glenn Cunningham Lake) (Standing Bear Lake) (Zorlnsky Lake) (Wehrspann Lake) GENERAL Locat1on of dam 93rdStateStreet 132ndandFortStreet 156thand"F"Street t56thandGIIesRoad R1Verandm1leage Knigll!Creek- TnbutaryBig Pap1o- BoxelderCreek- Trib.SouthBranchPapto- Dramage area (sq. m1.) 178 6 164 13.1 Reservoir length in miles 25 1.0 1.5 15 locallon of Damtender None None None None Traveltime to Missouri RNer 5·10Hours 5·10Hours 5·10Hours 5-tOHours Max. diSCharge of record Proje~:tcost(t) $11,800.00{) $4,~00,000 $20.656,000 $14,934,000 DAM AND EMBANKMENT 9 Topol dam ft. MSL 1152 11300 1143.5 1131 10 Lengthofdam-!t 1940 1460 1400 1810 11 Heightofdam-tt 67 70 64 59 12 Streambed-ft MSL 1085 1060 10795 1069 13 Abutment formation Lsanclayloess Lean clay loess Lsanclayloess Lean clay loess 14 Typeaffill Rolled earth Rolled earth Rolled earth Rolled earth 15 Fillquanii!YII'ICU yds 656,000 481,000 1.263.000 767,450 16 Date of closure 5Aug1974 30ct1972 15Julyt984 21Sept982 17 Oateolmillalfill 2Sept977 240ctt977 26 May 1987

SPILLWAY Olschargecapaclty-cls(max pool) 18,700 9.500 30,000 12,000 Crestelev -ft. MSL 1142 1121 1128.2 1120 Widlh-ft 700 250 400 600 Gates. number, size, type Ungatedearthchannel Ungatedearthchannel Ungatedearthchannel Ungatedearthchannel

RESERVOIR ELEV. AND AREA 22 Maximum pool 1147 117Ga 1127 36& 11382 860a 11258 ..... 23 TO!Jaflloodcontrolpool 1142 991a. 1121 302a. 11282 594a 11131 .... 24 Top at multipurpose~ 1121 377a. 1104 137a 1110.0 "" 1095.83 "" (See(2Jfootnote)

STORAGE ZONES (Eiev.-Ca~clt~) 25 Surcharge 1142·1147 5,405AF 1121·1127 2,010AF 11282·11382 7,225AF 1113.1-1125.8 8,12BAF 26 Flood control 1121-1142 13,899AF 1104-1121 3.720AF 11100-11282 7,585AF 109583-11131 6,119AF 27 Multipurpose 1085·1121 3,262AF 1060·1104 UOOAF 10605·1110.0 3,470AF 1069·1095.83 2,682AF 28 Grossstorage(Exct.olsurcharge) 17,161AF 5,220AF 11,055AF 8.801AF

OUTLET WORKS 29 NumberandSIZe-condults 1-RCP-54"dlameter 1-RCP-36 'diameter 1-RCP-48 'diameter 1- RCP-48"dlameter 30 Condultlength-lt 680 736 782 656 31 Oischargecapacityofcondult-CFS(attopofF.C.Pool) 570 160 490 490 32 Gatedoutlets(No. -slze-mvertelev.oflntakelnlt MSL) 1-30"x30" 1100 1-24"x36" 1080.0 1-30"x30' 1090.0 1-30"x30"diameter 1077.0 1-6''dlameter 1104.25 1-S"diameter 1090.0 33 DISchargecapacltyofgatedoutlets-CFS(atbaseo!F.C.Pool} 90 90 140 140 34 Ungated outlets (No. - s1ze- Invert elev. -ft. MSL) 2- 2 O'x 4 0' 1121 2-10'x25' 11040 2-15'x3.5' 1110.0 2-1.25'x3.5' 1095.83 2-25'x90' 11275 2-20'x6.0' 1109.0 2-3.15'x8.0 1117.6 2-367'x80' 1103.4

35 POWER INSTALLATION None None None None

M RO , ~~~~. 1590 (1) Costasol5·3·88 October 1989 (2) Based on a survey of July 1987theelevationaftheovertlowllp was changed from 1096.0 ft. MSLto 1095 83ft. MSL. SUMMARY OF ENGINEERING DATA - FEDERAL RESERVOIRS WITH AUTHORIZED FLOOD CONTROL MISSOURI RIVER TRIBUTARIES - U.S. ENGINEER DISTRICT - OMAHA SALT CREEK BASIN - NEBRASKA

ITEM DAM NO.2 DAM NO.4 DAM NO.8 DAM NO.9 DAM N0.10 DAM N0.14 DAM NO. 17 DAM N0.18 SUBJECT DAM NO. 12 DAM N0.13 NO (Olive Creek Lake) (Blue Stem Lake) (Wagon Train Lake) (Stagecoach Lake) (Yankee Hill Lake) (Conestoga Lake) (Twin Lakes) (Pawnee Lake) (Holmes Park Lake) (Branched Oak Lake) GENERAL Location at dam 1 5 mi. E of Kramer 25mi.W.o1Spragua 15mL N lit Holland 1 m1. S of HICkman 35mi. E. at Denton 1.5 mi. N. of Denton 2mLN.W.o!Pieasantdale 2 m1 N.W. at Emerald SE.edgeafllncoln 4ml. W of Raymond Rivera!Kimlleage S.Trlb.oiOIIveBr NTnb.oiOiiveBr N. Trlb ofH1ckmanBr S. Tnb of Hickman Br GardweiiBr HolmesCr M!ddleCr N Middle Cr. AntelopeCr OakCr Drainage area In square miles 82 166 156 97 84 15.1 11.0 35.9 54 88.7 Reservoir length in mites 12 16 18 14 0.7 14 1.5 3.0 07 37 Location o!Damtender none none none none none none none none none none Travel time to Lincoln, NE 23hrs 13hrs 14hrs 3hrs 8hrs 13hrs. 7hrs. 3hrs 6hrs Max discharge of record '"" (1} Pro,ectcost (1} (1} (1} (1) (1) (1} (1) (1) (1) OAM ANO EMBANKMENT Top of dam II MSL 1359.0 13340 13120 1294.0 1270.0 1260.0 13640 12710 12730 13200 10 Lengthofdam-11 30200 2760.0 16500 22500 31000 3000.0 20750 5000.0 77000 52000 11 Helghtofdam-11 450 57.0 52.0 48.0 520 630 580 650 550 700 12 Streambed -II MSL 13140 1277.0 12600 12460 1218.0 11970 1306.0 12060 1218.0 12500 13 ADutmentlormatlon Clay-sand-silt Clay-sand COy Clay-sand Clay-sand Clay-sand CU!y-sand-SIIt Clay-sand Clay-sand C~y-sand-slll 14 Type of fill Rolled earth Rolled earth RolleCearth Rolled earth Ao!ledearth Rolled earth Rolled earth Rolled earth Rolled earth Rolled earth 15 Flllquantitymcu.yds 312.000 471,000 376000 374000 502000 658000 610000 870000 900000 2460000 17Sep 1962 16 Date ol c~sure 20Sep1963 12Sep 1962 24Sep 1962 27Aug 1963 50ct. 1965 24Sep1963 26Sep 1965 16Jul1964 21Aug.1967 17 DateofinitU.Iflll 30Jun.1965 6Jul1963 24Jun.1963 25 May 1965 10Jun.1967 May 1965 16 Mar 1969 21Jun 1967 2Jun 1965 16Jan 1973

SPILLWAY 800atel12697 7825atel13175 18 Oischargecapaclty-cfs 15875atel13571 22925atel.13317 23210ate113098 17565atel1291.6 12100ate1.12678 27220atel.12582 25200atel 13616 19875atel1269.1 12660 1311.0 19 Crestelev -fl. MSL 13500 13225 13020 1285.0 12620 1252.0 1353.0 12635 2000 20 Width-It 3400 3400 4300 430.0 4000 750.0 4000 700.0 500 Ungatedearthchannel 21 Gates, number, size, type Ungatedearthchannel Ungatedearthchannel Ungatadearthchannel Unpatedearthchannel Ungatedearthchannel Ungatedearthchannel Ungatedearthchannel Ungatedearthchannel Ungatedearthchannel

R!.@ERVOIRELEV. AND AREA 1269.1 1672A 12697 437A 13173 4207A 22 Maximum pool 1357.1 470A 13317 969A. 13098 875A 12916 645A 1267.8 624A. 1258.2 755A 1361.6 645A. 12635 1408A. 12660 391A 1311.0 3640A Topoflloodcontrolpool 13500 355A 13225 1302.0 660A 1285.0 490A 1262.0 494A. 1252.0 620A. 13550 505A 23 none Topoljolntusepool '"' 12443 737A 12424 123A 1284.0 1780A 25 Topol conservatiOn pool 1335.0 174A 1307.4 1287.8 303A. 12711 196A 1244.9 284A. 12329 230A 13410 255A. " 12443 737A 12400 102A 12757 1270A 26 Topofsedunentpool 13350 174A. 1306.1 "'''"' 1284.6 225A 1271.1 196A 1241.9 176A 12329 230A 1337.4 205A STORAGE ZONES (Eiev.·Ga~acl!l:l 12620·1267.8 3242AF 12520-1258.2 4245AF 1355.0·13616 379UAF 12635-12691 8593AF 1266.0-12697 1534AF 13110·13173 24720AF 27 Surcharge zone 13500-13571 2910AF 13225-1331.7 7215AF 13020·13098 5990AF 12850·12916 3725AF 12329·1252.0 8030AF 13410·1355.0 5250AF 1244.3-12635 20290AF 12424-12660 5885AF 12640·13110 71570AF 28 ExclusiVelloodcontrolzone 1335.0·13500 3980AF 13074-1322.5 7113AF 12878-1302.0 6790AF 1271.1·1285.0 4700AF 1244.9-12620 5854AF none none none none 29 Jolntusezone none none none none 12400-12424 273AF 12757-1284.0 12740AF none 1306.1-13074 386AF 1284.6·12878 830AF none 1241.9-1244.9 593AF none 1337.4-1341.0 810AF none 30 Consarvationzone 1250.0-12757 13250AF 1116AF 11970·12329 2610AF 13060-1337.4 2020AF 12060·12443 7826AF 12180-12400 632AF 31 Sedlmentpoojzone 13140·13350 1490AF 1277.0-1306.1 2295AF 1260.0-12846 t660AF 12460-12711 1940AF 12180·1241.9 10640AF 8080AF 28116AF 6790AF 97560AF 32 GrossStorage(Excl.olsurcharge) 5470 AF 9794AF 9280AF 6640AF 7563AF

OUTLET WORKS 1-CMP-42""0ia 1 -CMP-60"0ia 1-CMP-60""013 1-CMP-concrete 33 Numberal\dslze-conduits 1-CMP-48" Oia 1-CMP-60"" Oia 1-CMP-60" Dia 1-CMP-48'"Dia 1-CMP-42"" 01a 1-CMP-60"' 01a Wlth30""RCPiining Wlth42'"RCPiining Wilh42"" RCPI101ng Lmed-72"" 01a With30"RCPilning W1th42"" RCPIInlng Wlth42"RCPilnlng Wlth30''ACPIIning With 3D"' RCPUning W11h42""ACPiinmg 335 382 320 370 34 Conduitlength-11 280 313 299 280 300 318 1-36'"xJ6""Uflgate-t2280 1-42"'x54""Uflgate-13330 1-42'"x60"'liflgate-1236.0 1-36""x36""llflgate-12390 t-48""x72"Liltgate-1274.0 35 Gatedoutlets{No -size-type-lnvert.elev) 1-36""x36" Uftgate-13300 1-36""x36""lrttgate-1303.0 1-36'"x36"llttgalfl-1283.5 1-36"'x36''liflgalfl-1261.0 1-36"x36"" Ultgate-1237.0 2-30"'x96"-12490 1-10" Ola.SIIdegate-1276.3 2-30"x96"-1l924 2-24''x72''-t277.1 2-18""x63"'-12500 2-30'"x96""-12423 2-24""x63"-13410 2-J.4''x120""-1244.3 36 Ungalfldoutlets{Openings-size-elev) 2-24""x72''-t340.9 2-30''x96"-1313.5 2-12'"x36""-12425 2-42""x144''-128395 2-12"x30"-13350 2-12"x54"-13074 2-12''x54'"-1287.8 2-t2''x30"'-1271.1 2-12"'x30'"-12449 2-12'"x54"'-12329 60 300 37 01sch. taDaC- cfs(Atbaseof EFC zone) 80 75 75 80 95 80 145 210

POWER INSTALLATION 38 No.andslzeofturbines 39 Noandrafingofgentrat01"5 40 Plantcapacity 41 Power Plantd1sch. capac {At baseol EFC zone)

October1989 {1) Total projectllnancialcostmcludingall dams= $12,075,000 (Cosl5are as of9-30-80) SUMMARY OF ENGINEERING DATA - FEDERAL RESERVOIRS WITH AUTHORIZED FLOOD CONTROL MISSOURI RIVER TRIBUTARIES - U.S. ENGINEER DISTRICT -OMAHA BUREAU OF RECLAMATION DAMS

ITEM NO SUBJECT BOYSI:N CANYON FERRY CLARK CANYON GLENDO HEART BUTTE JAMESTOWN KEYHOLE PACTOLA SHADEHILL TIBER YELLOWTAIL

Locationoldam 20mi.S.o1Thermopolls,Wy. 17 mi N E of HeN!na, Mont t8mi. S.W of DillOn, Mont 4 5 m1 S E otGiendo, Wyo 15 m1 S of Glen Ullin, N.D. 1 m1. N. o1 Jamestown. N 0 12 m1 N E ol Moorcrafl, Wyo 15 m1. W of Rapid Crty, S.O 1 mi. W ol Shadehill, S.D. t5 m1 S.W at Chester. Mont 45ml SW otHardm, Mont River and mileage Wind R.M 295 Missoun R.M 2253 Beaverhead N~rth Plane R M 280 Heart RM.103.5 James A.M.580 BelleFourche AM 289 RapldCr AM 110 Grand R.M 90 Manas R M 7! Big hom 3 Oralnagearaa1nsquarem11es 7710 15900 2320 14330 1710 1300 1950 319 3120 4850 19,626 Reservoir length in miles 17.5atel4725 25atel3800 5atel55604 15atel.4635 12atel2094.5 40atel1454 10atel4111.4 45atel.46215 toatel.2302 25atel30125 71atel 3657 location of Damtender Onstte Onslle Dillon, Mont Ons1te Ons1te none PactolaDam Ons1te none On site Ons1te TraveltlmetoMissouriRiver 6days 4.5daystoF! Pf!ck 2.5daystoThreeForks About 3 weeks 2days About 7 weeks 5days 3days 2days 1.25days 4days Max discharge of record 29.800 cis Jul. 1923 47000cfsJun.1908 3720CFSJun 1908 30000cfsJun 1908 30,500cts May 1970 ±8000cts Apr1969 12.000cfs Apr.1g24 2200cfs May1952 58,000cfs Apr1950 40,000cfs Jun1948 37,400cfs Jun 1935 PrOjectcost(t) $33,498,000 $42,546,000 $12,108,000 $44,371.000 $3.576.000 $3,717,000 $4,722,000 $7,861.000 $7,269.000 $44,909,000(1983) $95,900,000 DAM AND EMBANKMENT 9 Topol dam- fl. MSL 47580 3808.5 55780 4675.0 2124.0 14710 41340 46550(3) 23180 30260 36600 10 lengthofltam-lt. 1143 1000 2950 2096 1850 1418 3420 5290 12,840 4300 1450 11 He1ghtoldam-1t 150 225 1475 167 124 85 118 245 122 201 524 12 Streambed-fl MSL 4608 3635.5 5446.5 4508 2000 1386 4016 4422 2196 28235 3166 13 Abutrnent!Ofmatlon Sandstone-shale-limestone Sllate-slate Sand-bentomtlctuff Sandstone-shale Sandstone Pierre shale Sandstone and shale Slateandschlst Sand,slltandclay Shale and sandstone limestone 14 Typeoflill Rolledearth Concretegravlty Rolled earth Rolled earth Rolled earth Rolled earth Rolledearthandrock Rolledearthandrock Rolled earth Rolled earth Concretethm·arch 15 Flllquantltylncu.yds t,527,000 407,100 1,884,000 2,676,000 1,140,000 963,000 1,329,000 4,532,000 3.391.000 12,049,000 1546.000 16 Oateofclosure Oct 1951 Mar 1953 Aug. 1964 Jun 1956 Aug 1949 May 1953 Mar 1952 Aug.1956 Jul.1950 Oct 1950 Dec 1966 17 oateotmitlalfill{topolcoi!Serpool) Jun 1952 Jul1955 Jun 1965 May 1959 Apr 1950 Apr.1965 May 1978 Jun 1963 Apr1952 Aug 1956 Jun 1S67

SPILLWAY 1Sel"o'IC8) 5700 127.000cfs 68,470 92000 18 Dlschargecapaclty-cfs(Max pool) 20,000atel4725 150,000 9530 10,300 5650 2930 11000 255,000 22719 2302.0 29750 35930 19 CresteN!v -fl. MSL 47000 37660 5560.4 46530 20645 1454 40993 46215 1500 66 50(net) 20 Wldth-fl 60{netl 66(totall 204(netl 222(gross) 100 27 9.5 19.25 425 2{30x25fl)radial Ungated Ungated 3- 22~38 It rad1al 2- 25~64.4 It radial 21 Gates, number, size, type 4 {51x34 5 H) radial Un113ted chute "Ungated agee welf Ungatedglol)lhole Ungatedgloryhole Ungal&d ogeewe1r Ungated ogeewe1r Glory hoM! eartncnannel RESERVOIR ELEV. AND AREA 12,t50a 3020.2 25,41Da. 36600 22 Maximum pool 4752.0 30,86Qa 3800.0 33,535a 55719 6600a. 46690 23,30Da 21182 10.950a 1464.4 17.43Da 4128.7 10.730a 4651.7 1,560a 2312.0 17.94Da 23,150i 3657.0 23 TopotlloodcontroiJ)OOI 4732.2 22,17Qa 38000 33,535a 55604 5900a 46530 17,9903 2094.5 6,580a 1454.0 13,210a 4111.5 13,7303. 4621.5 1,23Qa 2302.0 9900a. 3012.5 17,280a 17.890a 36400 12,600a 24 Topofjoln1uSIIpool 4725.0 19,560a. 37970 32.800a 5546.1 5160a 1432.67 2.- 2993.0 13,79Qa 36140 25 TopotconSIIrvatlonpool 4717.0 16,960a 37700 24,125a 55357 4495a 46350 t2.370a 20645 3,400a 14298 2.09Da. 40993 9,410a 4580.2 860a 2271.9 4800a. 2976.0 6915a 11,71Qa 35470 26 Topotlnacti'IIIJ)OOI 4685.0 9,28Da. 3728.0 11.480a 54706 220a 45700 3,130a. 20300 800a 14000 160a. 4051.0 82Da. 4456.1 1QOa. 2250.8 280Da. 29664 415Da

STORAGE ZONES (Eiev.-capaclty) 27 Surclwgezone 47322-4752.0 520.700AF 5560.4·55719 71,830AF 46530-46690 329.300AF 2094.5·21182 206,400AF 1454.0-1464 4 158,900AF 4111.5-41287 294,800AF 4621.5-4651.7 41.892AF 2302.0-2312.0 111,200AF 3012.5-3020.2 187.740AF 36570-36600 52,830AF 28 Excluslvefloodcontrolzone 4725.0-47322 150,400AF 3797.0-3800.0 99,460AF 55461-5560.4 79,090AF 4635.0-46530 271,900AF 20645-2094.5 147,900AF 1432.7-1454.0 185,400AF 4099.3-4111.5 140,500AF 4580.2-4621.5 43,057AF 22719-23020 218,300AF 29930-30125 400,900AF 3640.0-3657.0 258.330Af 29 Jotntusezone 47170·4725.0 146.100AF 3770 0-3797 0 795,135AF 55357·55461 50.440AF none none 14298-14327 6,600AF none none 2976.0-29930 268.oooAF 36140·36400 240,340AF 30 Consel"o'ationzone 4685.0-4717.0 403,800AF 3728.0-3770.0 711,460AF 54706-55357 126.120AF 4570.0·4635.0 454,300AF 2030.0·20645 69,000AF 1400 0-14298 28,100AF 40510-40993 185.800AF 4456.1-4580.2 54,955AF 22508-22719 80,900AF 2966.4-29760 121,700AF 3547.0-36140 336.100AF 31 lnactivezone 46080-46850 252,100AF 3635.5-3728.0 445,455AF 54465·54706 1,510AF 4508.0-45700 63,200AF 2000.0·2030.0 6,800AF 1386.0-1400 0 820AF 40160-4051.0 8.000AF 4422.0-4456.1 1.017AF 21960-2250 8 58,200AF 2823.5-2966.4 577.620AF 31660-3547.0 493,580AF 32 GrossStDfage(Exclolsurcllargel 952,400AF 2,051,520AF 257,150AF 789.400AF 223.600AF 221,000AF 334,200AF 99,029AF 357,400AF 1.555.960AF 1,J28.360AF

~ 33 Numberandsize-condurts 1-661n.I.D. 4-Min 10 1-911.10 1-21111.0 1-63111 1.0 1-9.511 -135ft 1-9.5x8.25 1-6tt 1-7tt.ID. 1 condu1tcontammg 2-841n 1-57in 10 1-1311.1.0 pump intake 1-72".1-22"pipes 1-9.511 34 Conduitlength-ft 300 84in.-115 741 2300 597 443.75 653.4 740 355 72"-111022"-1090 289-216-305 35 No. -s1ze-typegates 2-48in.Jetvalves 4-771n.Siide9500 2-3x6.511 Slide 3-725x77511 Slide 1-4x5tt. Slide 2- !)~6 It Slide 2-3.5x3.5ft.Siide 2- 2.75~2.7511 Slide t-6x6ft rad~al 1-5~5· Slide.1-18" butterfly 3-bulkheadgates 36 Disch capac.- cts{AtbueotEFCzone) 66in -640 1-13ft lila 600 2200 11.300 690 2175atel.14298 1250 1020 600atel2260 1425atel.2993 84m -2500each 57in.-670 3-13.5fl.dia.5,970 Au~ihary Outlet (see (2) footnote) 9511-862

POWER INSTALLATION 37 No.arMisizeolturbmes 2-10,500HP 3-23.500HP 2-16,750HP 4-87,500HP 38 No.arMiratingolgeneratMs 2 -7500KW 3-16,667 KW 2-12,000'f;W 4-62,500KW 39 Pfantcapacity 15,000 KW 50,000 KW 24.000KW 250,000KW 40 Power Plant dlsch. capac. {At base of EFC zone) 2300cfs 5200c1s 3300cls 7800cfs

(1) These costs to complete the dam and reservoir, the associated recreation and fiSh and w~dllle facntties and the power plant W8ffl applicable. Costs (3} Pactola Dam was ra1sed 15 teet 1111987 October1989 donotlncludeirrigatlonfacllltiesexceptthoselocatedatthedam. Costsareasof6-30·76

(2}TIBERAUXIUARY OUTLET No.andsizeofcondults 1-10.75ti.I.D Conduit length-fl. 1535 No.-Size-Typegates 1-7.25x9.25ft.sllde 2-7.0x12.0ft.sllde Discharge capacity-cis 4250ateL 3020.2

(3) Pactola Dam was ra1sed 15feet in 1987 PERTINENT DATA PERTINENT DATA

SPRING CREEK DAM SNAKE CREEK DAM (LAKE POCASSE) (LAKE AUDUBON) location • On Spring Creek ar• of Lake Oahe, at Pollock, South Dakota Location- On Snake Creek er• of Lake Sakakawee, approxlaately 12 miles northeast of Garrison Da•, North Dakota. ~ • It is e road relocation route for the area inundated by Lake Oahe. Control structures ere provided to regulate Lake Pocaase for fish ~ • The de• end reservoir are a relocation route for end wildlife, and recreation. transportation facilities and utilities which were Inundated by Lake Sakakawea, a regulating reservoir for the Bureau•• Garrison Diversion ~Area - 660 sq. •1. (224 sq. ai. of which Is non-contributing). Unit, and provide for fish and wildlife, and recreation.

~ 102 Embankment Drainage~- 250 sq. •i. (110 sq. •i. of which Ia non-contributing).

Type of Fill · Rolled Earth ~ and Embankment Top of Da• Elev. - 1625 ft. MSL Length of De• • 3,200 ft. Type of Fill - Rolled Earth Height of De• - 40 ft. ••xiaua Top of De• Elev. • 1865 ft. MSL StreaMbed - 1585 ft. MSL Length of Da• • 12,900 ft. Date of Closure - 1961 Height of Dam • 85 ft. ••xiaua Date of Initial fill • Between 1961 and 1964 StreaMbed - 1780 ft. MSL Date of Closure - 1952 ~ • Nine 6 x a ft. uncontrolled box culverts with a crest Date of Initial Fill • Sept. 1975 elevation of 1617 ft. MSL. ~ • None (An original designated ungated spillway of l • 60• Reservoir Elevatjons. a.tn.!!!Sl~ culverts with a crest of elevation of 1850 was filled In and closed In 1972 when the eMbankment was widened to provide for a four lane highway. £.!.... !!1!. Acres Acre-Fe!t It was located 180 ft. north of regulating conduit).

Top of Eabank•ent 1625 2,560 26,000 Reservoir Elevations. !£!! .!!!Sl ~ Spillway Crest 1617 1,520 11,000 Top of Mid-level Outlet 1614 1,130 7,000 fL. !!.a. w:n Acre· feet Invert of Mid· level Outlet 1609 500 3,440 Invert of Low-level Outlet 1602 60 1,000 Maxlaua Noraal Operating Pool 1850 20,620 396,000 StreaMbed 1585 0 0 Mlniaua Nor•al Operating Pool 1847 18,780 336,870 Top of Inactive Pool 1810 1,450 13,180 2Y!l!1 ~ · One 5 ft. CMP conduit with a 5 x 5 ft. sluice gate, S t realllbed 1780 0 0 invert elev. 1602 and a 5 x 12 ft. overflow roller gate, invert elev. 1609. 2Y!l!1 ~ - A 7 x 10 ft. reinforced concrete conduit, Invert elev. 1810, regulated by a 7 x 10 ft. sluice gate. An external crane is required to operate the gate. Located about 3,poo ft. south of north end of ••In eMbankment. Discharge capacity 2,300 c.f.s. under 15 ft. head differential. Two 7 x 10 ft. bulkheads one on each side of sluice gate. Stilling basin on Garrison side. TOTAL NUMBER OF FLOOD CONTROL

RESERVOIRS IN

OMAHA DISTRICT

Appendix 3 TOTAL NUMBER OF FLOOD CONTROL RESERVOIRS IN THE OMAHA DISTRICT MONITORED AND/OR REGULATED AND REPORTED BY THE RESERVOIR REGULATION SECTION

TRIBUTARY AS OF MAIN ------1 JAN STEM ~ U.S.B.R. TOTAL*

1937 0 0 0 0 1938 1 (Ft.Peck) 0 0 1 1939-48 1 0 0 1 1949 1 1 (Cherry Creek) 0 2 1950 1 1 1 (Heart Butte) 3 1951 1 1 3 (Shadehill, Tiber) 5 1952 1 1 4 (Boysen) 6 1953 2 (Ft Randall) 2 (Cold Brook) 5 (Keyhole) 9 1954 3 (Garrison) 3 (Kelly Road) 6 (Jamestown) 12 1955 3 3 6 12 1956 4 (Gavins Pt) 4 (Bull Hook-Scott Coulee) 6 14 1957 4 4 8 (Glendo, Pactola) 16 1958 4 4 8 16 1959 5 (Oahe) 4 8 17 1960 5 5 (Cedar Canyon) 8 18 1961 5 5 8 18 1962 5 5 8 18 1963 5 8 (Salt Creek) 8 21 1964 6 (Big Bend) 11 (Salt Creek) 8 25 1965 6 12 (Salt Creek) 9 (Clark Canyon) 27 1966 6 14 (Salt Creek) 9 29 1967 6 15 (Bowman-Haley) 11 (Yellowtail,Canyon Ferry) 32 1968 6 16 (Salt Creek) 11 33 1969 6 16 11 33 1970 6 17 (Cottonwood Springs) 11 34 1971-73 6 17 11 34 1974 6 20 (Pipestem,Chatfield,Papio) 11 37 1975 6 21 (Papio) 11 38 1976 6 21 11 38 1977 6 21 11 38 1978 6 22 (Bear Creek) 11 39 1979-82 6 22 11 39 1983 6 23 (Papio) 11 40 1984 6 24 (Papio) 11 41 1985-90 6 24 11 41

*Two Subimpoundments (Lake Pocasse and Snake Creek) are not included. REGULATION SHEETS FOR PAST YEARS

Appendix 4 CORPS OF ENGINEERS PROJECTS

BEAR CREEK DAM BOWMAN-HALEY DAM I • BULL HOOK DAM ~ ~ CEDAR CAYON DAM I CHATFIELD DAM CHERRY CREEK DAM COLDBROOK DAM COTTONWOOD SPRINGS DAM

I '- KELLY ROAD DAM PAPIWON DAM NO. 11 PAPIWON DAM NO. 16 PAPIWON DAM NO. 18 PAPIWON DAM NO. 20 PIPESTEM DAM SALT CREEK DAM NO. 2 SALT CREEK DAM NO. 4 SALT CREEK DAM NO. 8 SALT CREEK DAM NO. 9 SALT CREEK DAM NO. 10 SALT CREEK DAM NO •. 12 SALT CREEK DAM NO. 13 SALT CREEK DAM NO. 14 SALT CREEK DAM NO. 17 SALT CREEK DAM NO. 18 SNAKE CREEK DAM SPRING CREEK DAM BEAR CREEK DAM AND LAKE BEAR CREEK, SOUTH PLATTE RIVER BASIN, COLORADO 1989-1990 REGULATION

The Omaha District entered into two temporary one year storage con tracts for municipal and industrial water supply under Section 6 of the Flood Control Act of 1944 (Public Law 34, 78th Congress), pending development of a long- term contract under the Water Supply Act of 1958, as amended (43 U.S. C. I 390 b-f). The first contract dated September 17, 1987 was for 25 acre feet • with the Indian Hills Water District. This contract was renewed on December 5, t 1989. The second contract dated April 1, 1988 was with the Town of Morrison ~ for 49 acre feet of storage. This contract was renewed on April 1, 1990. The I cost of storage per acre-foot in each of these contracts is $1,650 and $1,726, respectively.

In response to the contracts for temporary water storage a revised Memorandum of Understanding (MOO) between the Corps of Engineers and the State of Colorado was signed on June 20,1988. This memorandum supersedes the previous MOO dated May 11, 1977. Under normal conditions the Bear Creek Dam outlet works is set to automatically pass streamflow up to 500 cfs when pool elevations are above the drop inlet-outlet weir crest of 5558 feet MSL. When conditions warrant, higher releases are made by opening two slide service gates in the dome type gated control structure buried under the embankment. Under the revised MOO, the State Engineer or his representative will determine the storage and releases necessary to satisfy downstream water right requirements when the pool level is below elevation 5559 ft MSL. Elevation 5559 is one foot into the flood storage zone and was selected to allow flexibility in targeting authorized pool levels. Bear Creek Reservoir was not made operational during the reporting period as has been done in the past.

The State of Colorado, Department of Natural Resources, Division of Game, Fish and Parks in a letter dated October 1, 1970 agreed to provide water for the initial filling and replenishment of evaporation losses from the recreation pool, by purchase or other means, consistent with Federal and State laws to assure effective operation of the project for recreation. For the 1990 irrigation season, the Colorado Department of Institutions provided its full entitlement to the Simonton Ditch to replace the evaporation losses from the recreational pool.

Runoff during the reporting period was 47 percent of normal. Snowmelt runoff occurred during February and March with inflows reported at 92 percent of the historic average. Record low inflow of 250 AF (8t of normal) occured in August 1989. A total of 201 AF of the 28,757 AF flood storage zone was utilized. No flood control was achieved during this period. Maximum of Record:

Daily Inflow-Data Daily outflow-Date

Highest 910 cfs May 1 80 800 cfs May 5-12 80 2nd 690 cfs Jun 10 79 800 cfs Jun 12 79 3rd 625 cfs May 23 83 605 cfs Jun 29· I Jul 2 83 t Pool-Date 1 Highest 5581.0 Jun 23 83 I Lowest 5576.3 May 19 80 3rd 5567.9 Jun 10 79

Minimums of Record (since initial fill) :

Pool Date

Lowest 5556.98 Feb 9 82 2nd 5557.08 Jul 9 86

Reporting Period: (August 1, 1989 tbzough July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

193,3, ''' of normal 19057, '7' of normal Peak Daily Inflow (CPS) Peak Daily OUtflow (CPS)

131, Apr 23 133, Jul 9

Peak Pool Elevation (Ft MSL) Minimum Pool Elevation (Ft. MSL)

5559.81, Jul 8 5557.69, Sep 7 BEAR CREEK DAM AND LAKE BEAR CREEK, SOUTH PLATTE RIVER BASIN, COLORADO 1"989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

5590 1 1 (TdP OF FLobo CO NTR ~L 'zdNE EL ~6~5.b) '

5580

~ 5570 (/). ~

5560 J I, A ti _'!- .J._ r ~__ .... >A .A .~ ... II-" w ~ -~-~ :J!~ ~-·~ ~- :-"!!' ~ rA--- ~ ------I.&.. ~ -- .. TOP OF MUL TIPURPOSE ZONE (EL 5558) 6 5550 1- < >w d 5540

5530

5520 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS REPORT PERIOD

,i BOWMAN -HALEY DAM AND LAKE GRAND RIVER BASIN, NORTH DAKOTA 1989-1990 REGULATION

Beginning on August 21, 1989 and ending on October 3, a release of 2 cfs was made through the low level drawndown tube. Approximately 175 acre feet of water was discharged.

Maximums of Record:

Daily Inflow-Date Daily Qutflow-Date

Highest 5,310 cfs Mar 27 78 2,390 cfs Mar 28 78 2nd 1,770 cfs Mar 11 72 1,124 cfs Mar 14 72 3rd 1,755 cfs Mar 21 69 930 cfs Mar 30 71

Pool-Date

Highest 2762.66 Mar 28 78 2nd 2758.50 Mar 13 72 3rd 2758.08 Mar 30 71

Minimums of Record (since initial fill):

Pool-Date

Lowest 2749.93 Nov 16 81 2nd 2750.84 Feb 16-20 89

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Iotal Outflow

2486, 12% of normal 242, 2% of normal

Peak Daily Inflow (CFS) Peak Daily Qutflow CCFS)

46, Mar 1 3, Jul 21

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation

2753.11, Aug 1 2751.43, Jul 31 BOWMAN-HALEY DAM AND LAKE GRAND RIVER BASIN, NORTH DAKOTA 1989-1990 REGULATION

A 10-year pool elevation hydrogroph is shown below, with the current reporting period expanded for ease of reading. 2760 1 1 (T0P oF- FLooo cONTR 'o~ z~N~ EL 27~7) '

2758 . _J. Cl! 2756 :::e TOP OF MULTIPURPOSE 1- ~ ~ ZONE {EL 2754.8) w j_ - w ~------fl - ~\------u.. 2754 ~- 1\-- -¥ .. '\. z '-. \ I\ 0 ' \ 1- fr' !"-- <( h 1\ I'-- I f'v. ~ 2752 \ l1 1'. J 1-1 _J \. "' I\ w \ 2750 f\

2748 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I BULL HOOK~SCOTT COULEE DAMS MILK RIVER BASIN, MONTANA 1989-1990 REGULATION

Bull Hook and Scott Coulee Dams are both part of the Bull Hook Unit providing flood control for the city of Havre, Montana. Bull Hook and Scott Coulee dams are both located south of Havre on Bull Hook and Scott Coulee Creeks, respectively. Under normal circuastances the conduit valves of both dams will be kept partially open to evacuate accumulated storage as expeditiously as possible to allow the dams to function as flood protection facilities if excess runoff occurs upstream. Valve openings are to be maintained that will allow only the minimal damages to occur in the city of Havre. At times of high flows on the Milk River it may be necessary to shut off releases in both dams to prevent flooding behind the Milk River levees.

No storage accumulated during the report period. Inflow was negligible and outflow was zero for the period. No flood control was achieved.

-----~-~--~ BULL HOOK - SCOTT COULEE DAMS MILK RIVER BASIN, MONTANA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the I I current reporting period expanded for ease of reading. 2600 r 1 1 TJP oFI FLobD c~NT RbL z~N~ (JL 25,93~ I ------2590

--! 2580 (/). ::!! INORMALLY DRY - NO RECORDS KEPT I Lj 2570 w L&..

~ z SCOTT COULEE STRE AM BED ( EL 2560) 0 2560 t- <( >w d 2550

BULL HOOK STREA BED (EL 2540) 2540

2530 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I CEDAR CANYON DAM" (RED DALE GULCH) RAPID CREEK BAS IN, SOUTII DAKOTA 1989-1990 REGUlATION

Cedar Canyon Dam is located on the western outskirts of Rapid City, South Dakota. The dam is. des.igned. as" a detenti.on structure with no permanent storage, however, a small pool may sometimes exist in the dead storage below the inv.ert of the. au.tlat pipe. The. dam collects. runoff from approximately 261 acres. The outlet and spillway are uncontrolled. No water accumulated during the report period. Inflow was negligible and outflow was zero for the period. No flood control was achieved..

.,, CEDAR CANYON DAM (RED DALE GULCH) RAPID CREEK BASIN, SOUTH DAKOTA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 3550 I I I I TOP OF FLOOD CONT RL UNJ cL '3L~ I 3545

• 3540 .....J. (/). I NORMALLY DRY - NO RECORDS KEPTj ::E 3535 1-- w w LL.. 3530 z ~ 0 TOP OF INACTIVE Z0 NE (EL 3526 ------~ 3525 w> .....J w 3520

3515 STREAM BED (EL 3 512) ------r----r----1 ------3510 r-r-r-- 79 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I CHATFIELD DAM AND LAKE SOUTH PLATTE RIVER BASIN, COLORADO 1989-1990 REGULATION

Before the dam became operational, the Corps (CEMRO-ED-HC) requested that the Colorado State Engineers office acting through the District 8 Yater Commissioner assume responsibility for determining releases from the multipurpose pool in an effort to keep the Corps free of water rights conflicts. This relationship was put into a formal document dated March 30, 1973 when the multipurpose pool was increased from elevation 5430 to 5432 ft. MSL and contained water storage commitments by the State. By contract, the State is committed to keeping the pool above elevation 5423 for recreation and fish and wildlife purposes. Since 1979, the City of Denver through the State of Colorado has been permitted to regulate storage in the conservation pool in return for the City's commitment to provide sufficient water in the pool for recreation. The City is committed ot keeping 20,000 AF (Elevation 5426.94 ft. MSL) of water in the pool from May 1 through August 31, and permitted to use 10,000 AF of storage space in the reservoir between elevations 5423.8 and 5432.0 ft. MSL. The original top of multipurpose pool level was at elevation 5426 ft. MSL.

The pool entered the flood control zone on March 25 and remained above elevation 5432 through May 8, 1990. The total monthly inflow for October was 3,014 AF (37% of normal) and established a record low total inflow for the month.

Flood storage space utilized was 962 AF of 206,945 AF or 0.5 percent of the flood storage space. No flood control was achieved during this period.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 3,370 cfs May 30 83 3,034 cfs May 15 84 2nd 3,155 cfs May 09 80 3,027 cfs May 27 87 3rd 3,030 cfs May 15 84 2,858 cfs Jul 08 83

Pool-Date

Highest 5447.58 May 26 80 2nd 5447.08 Jun 30 83 3rd 5445.97 Jun 16 83

Minimums of Records (since initial fill):

Pool-Date

Lowest 5424.46 Nov 17 85 2nd 5425.20 Dec 06 81 Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow CAfl Total Qutflow CAFl

84526, 44t of normal 78097, 4lt of normal

Peak Daily Inflow CCfSl Peak Daily Qutflow CCFS)

700, 9 Jul 675, Aug 1

Peak Pool Eleyation CFt. M$Ll Minimum Pool Elevation CFt. MSL)

5432.57, Apr 20 5426.19, Dec 19

------. -- ' ' I~·' ~ • '~ '' CHATFIELD DAM AND LAKE SOUTH PLATTE RIVER BASIN, COLORADO 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 5450 1 doP o~ FLdoo dONTR 'o~ z~Nk ~L 55~o) '

5445

0 5440 .....J 0 (/) 0 TOP 0 F MULTIPURPOSE :::!! 5435 zo NE (EL 5432) 1- w I". l1IJ -- ~ ------~ -- - -- ~ - -- w ,._!'V' ~-- -- ~ ~~ ~ '1 J~ ~ J --n-- ~- LL... 5430 II J .. v 1/ z ~ ../\...... _ \1\ 0 ~ ~ ~ v \ / ~ 5425 \ ~A ~ >w .....J w 5420

5415

5410 80 81 82 83 84 85 86 87 88 89 ASONDJFMAMJJ 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I Cherry Creek Reservoir Release Sunaary (As of October 31, 1989)

MAXIMUM DAILY AVG PEAK RELEASE RELEASE RELEASE DISCHARGE (3) YEAR (A. F.) MONTHS (1) (c.f.s.) (c.f.s. - date) ------1948 Embankment closed October 1948 (Gates reatained open) 1949 All Year 1950 936 All Year 1951 2,563 All Year 69 635 Aug 23 1952 2,367 All Year 51 321 Aug 29 1953 2.008 All Year 55 465 Aug 27 1954 1,574 All Year 104 480 JuT 21 1955 2,631 All Year 315 1,270 Aug 05 1956 2,795 All Year 727 1,440 Jul 31 1957 945 Jan thru May; C~) 190 315 May 09 1958 535 Jun, Jul, Aug 138 502 Jul 19 1959 174 Jun 62 106 Jun 03 1960 6,690 Mar, Apr, May 450 532 Mar 26 1961 880 Aug 330 508 Aug 07 1962 2,635 Feb, Mar 135 139 Feb 12 1963 2,010 Aug 250 260 Aug 07 1964 1,700 Apr 124 130 Apr 04 1965 16,620 Aug. Sep 560 574 Aug 06 1966 1,160 Apr 270 275 Apr 25 1967 NONE 1968 NONE 1969 NOliE 1970 920 Mar 125 144 Mar 25 1971 NONE 1972 NOICE 1973 19,580 Apr thru Jul 375 394 Jun 12 1974 12,300 Feb thru May 260 275 Mar 19 1975 1,820 Apr, May 57 85 Apr 23 1976 NONE 1977 NONE 1978 NONE 1979 NONE 1980 20 May Jul 5 75 Jul 13 1981 NOliE 1982 NONE 1983 23,835 Apr thru Aug 330 344 Apr 22 1984 35,535 Feb thru Dec 250 271 Aug 31 1985 17,045 Jan, Mar-Jun, Oct, Dec 300 302 Jun 03 1986 7,620 Jan thru Apr ' 200 (5) 625 Apr 16 1987 17,080 Feb-Jun, Aug, Nov, Dec 180 (6) 170 Jul 04 1988 13,820 Jan-Jun • Sep 135 (6) 286 Apr 19 1989 5,140 Jan-Jun 27 27 Mar 01.:29 1990 1,760 Mar-Apr 45 94 Mar 28

(1) Prior to Mly 15, 1957 gates on occassion were temporarily lowered for the flood control. {2) Gates closed on May 15. initiating perunent storage in the reservoir. (3) Determined by USGS gaging station 2000 ft. below the dam. {4) MaximUII of record since 1950 {5) Reservoir flushing operation, maximum release was 800 cfs for five minutes. (6) Reservoir flushing operation. maximum release was 800 cfs for ten minutes from each of the four gates. CHF.RRY CREEK DAM AND LAKE CHERRY CREEK, SOUTH PLATTE RIVER BASIN, COLORADO 1989-1990 REGULATION

Inflows to Cherry Creek Reservoir for the reporting period were 68% of average (5,300 AF). Inflows peaked in March with 1,690 AF of water entering the reservoir.

On July 25, 1988, the Omaha District received a request from the Colorado Department of Natural Resources to raise the conservation pool level at Cherry Creek reservoir to elevation 5552.0 ft. MSL. This change would allow the Department of Natural Resources to fully use the storage right that they hold and would provide some operational flexibility to store early spring runoff and deliver it at a later date. The Corps is preparing an environmental assessment required to receive approval from the Missouri River Division.

Releases from the project were made to evacuate flood control zone storage and to meet downstream calls. The pool was allowed to rise up to elevation 5552.0, two feet above the normal multipurpose pool elevation, in order to store water for later use in downstream calls and to help make up for evaporation losses. Water was also stored in Chatfield for the same purposes. The state was notified that this operation would be allowed on a temporary basis only until an investigation and an environmental assessment were completed.

The annual flushing operation to remove sediment from the intake structure was postponed during this reporting period. The Cherry Creek Valley Water and Sanitation District reported that "undermining of the creek bed has washed out the steel piling originally installed to protect water lines" located at Cherry Creek Drive and Iliff Avenue.

The flushing is scheduled to be completed in the spring of 1991. Work has been started in October 1990. A total of 1,523 AF or about 2 percent of the 79,960 AF exclusive flood storage zone was utilized. No downstream flooding was prevented by this project.

Maximums of Records:

Daily Inflow-Data Daily Outflow Data

Highest 5565.82 Jun 03 73 6,150 cfs Jun 16 65 560 cfs Aug 7-8 65 2nd 5562.52 Aug 01 65 3,195 cfs May 06 73 375 cfs Jun 08 75 3rd 5557.89 Jul 25 83 1.440 cfs Jul 24 83 330 cfs Apr 23-May 1 83 May 28-Jun 2 83 Maximum Hourly Infow: 56,000 cfs 7-8 p.m., June 16, 1965.

Minimum of Record (since initial fill):

Lowest 5543.51 Jan 29 65 2nd 5545.90 Nov 23-24 78 Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow CAF) Total Outflow CAF)

5300, 67% of normal 1760, 34% of normal

feak Daily Inflow CCFS) Peak Daily Qutflow CCFS)

105, Mar 6 45, Mar 31; Apr, 2 Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation

5551.75, Mar 30 5549.98, Oct 29

. ' CHERRY CREEK DAM AND LAKE CHERRY CREEK, SOUTH PLATTE RIVER BASIN, COLORADO 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 5560 I I I 111~111 I (TOP OF FLOOD C ONTR OL ZON EL 5598) / ...... _,....., 5558

• 5556 ....J. Vl. :=!! 5554 w~ w LL. 5552 ~ tvr 1'--. z r\J lr' ~"""" 0 (\ / r-. .._ ~ I tv rv-. ~ v ~ 5550- ~ ~~ v~ >w / ....J \ TOP OF MUL TIPURPOSE ZONE (EL 5550) w 5548 ~ I'\ A ~'f\.. I 5546

5544 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS REPORT PERIOD COLD BROOK DAM AND LAKE FALL RIVER BASIN, SOUTH DAKOTA 1989-1990 REGULATION

Releases from Cold Brook Reservoir are regulated to comply with State water law. Larive Lake Resort, located below the dam, holds a senior water right entitling it to the Cold Brook Reservoir inflow up to 1.1 cfs.

A dam safety exercise was held for Cold Brook Dam May 16-17, 1990. The purpose of the exercise was to evaluate the District's response to an emergency situation. As a result of the exercise, a flood warning system was installed in July, 1990.

Maximums of Record:

Daily Inflow-Date Daily Qutflow-Date

Highest 74 cfs Ju1 14 62 2.4 cfs Mar 23 87 2nd 65 cfs Ju1 8 61 2.0 cfs May 16-20 72 3rd 40 cfs May 19 82 1.9 cfs Oct 1 72 Jan 7 73, Jun 9-11 75 May 2-7 76 Pool-Date

Highest 3585.38 Aug 17 82 2nd 3585.26 Jul 22 82 3rd 3585.25 Jan 12 85 Feb 22-24 85 Mar 23/May 3 87

Minimums of Record (since initial fill):

Pool-Date

Lowest 3576.6 Oct 22 77 2nd 3576.8 Sep 14-0ct 2 81 Sep 21-22 77

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Qutflow (AF)

332, 53% of normal 276, 57% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

2.5, May 29 .5, Aug 89

Peat Pool Eleyation (ft. MSL) Minimum Pool Elevation C[t. MSL)

3582.06, Aug 1 3580.57, Jul 31 COLD BROOK DAM AND LAKE FALL RIVER BASIN, SOUTH DAKOTA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

3588 I I I I I I I _I I I ~ I I (TOP OF FLOOD CO NTR OL ZONE EL 3651.4) I I I I I I I I I I I TOP OF MULT !PURPOSE ZONE (EL 3585) 3586 \ - r------~ n------~------rv ~------.. --- --~------~ 3584 I (/). IN ::E \ \ ti 3582 ./ w ~ .\ LL. ~· \....J' 1'---. 1'--. lr- ""\..J ~ ~ \ ~ - ~ z 0 3580 i!\ I- < w> d 3578 \ ~M v~v 3576

3574 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I

i COTTONWOOD SPRINGS DAK AND LAKE FALL RIVER BASIN, SOUTH DAKOTA 1989-1990 REGULATION

During the Cold Rrook Dam safety exercise (May 16-17, 1990) the simulated partial filling of Cottonwood Dam was being monitored by the Rig Rend Project Office and the Monitoring and Evaluation Section of the Omaha District. The role of the observer at Cottonwood Springs was also a siJBulation. During the simulation, the observer was found to play an important part in getting information to the District.

Maximums of Record:

Pool Date l)ail,y Inflow-Date Daily Outflow-Date

Highest 3847.9 Jun 9 79 2nd 3845.7 Mar-Apr 83

Report Period: (August 12, 1989 through July 31, 1990)

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

3834.5, Aug 1 3832.4, Sep 30

'.' ·t'illi'!'il;•:>-~ ' ·~·- ,. ·' 1~', ·'·\; COTTONWOOD SPRINGS DAM AND LAKE FALL RIVER BASIN, SOUTH DAKOTA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

3852 1 1 cr'oP OF FL~oo cONTR 0L ZON~ EL 3936) I I I I I I I I I I I I I I 3850 1 (roP oF MUL TIPU RPO SE I Z~NE EL ~875) I 3848

~. 3846 ~ ( I- 3844 \ r\ w ~ w j u.... 3842 \ ~ r 1\ z ~ \j J 0 I- 3840 1\ 1\ h \ <( \_ > \ ~ 3838 \ w 3836 \ I \ 3834 \ ' \ PC Ol DRY L 3832 """ 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I KELLY ROAD DAM SAND CREEK BASIN, COLORADO 1989-1990 REGULATION

Kelly Road Detention Dam is located on Westerly Creek, a tributary of Sand Creek and the South Platte River and provides flood control for the City of Aurora. It is located entirely within the boundaries of Lowry Air Force Base. The project's sole purpose is flood control and was not designed to permanently store water. Water is automatically impounded by the project and released through a ground level 24-inch CMP conduit or high overflow inlet. A gate on the 24-inch conduit is kept in the open position. The intended closure of the gate is to contain oil or other spills within the air base. The City of Aurora is responsible for obtaining pool gage readings during flood periods and general observation of project operation. KELLY ROAD DAM SAND CREEK BASIN, COLORADO 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 5370

5365 TOP OF FLOOD CONT ROL ZONE (EL 5362) ------! 5360 (/). ~ ~ 5355 w Ll.. !NORMALLY DRY - NO RECORDS KEPTI z ~ .,_0 5350 < >w .....1 5345 w

STREAM BED (E L 5340) 5340

5335 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS I REPORT PERIOD I GLENN CUNNINGHAM DAM AND LAKE PAPILLION CREEK BASIN - NO. 11, NEBRASKA 1989-1990 REGULATION

Due to heavy precipitation, the pool level entered the flood control zone in September and remained until the first part of November when it receded be low the flood control zone and stayed. It re-entered the flood control zone in March and stayed through July receding below the flood control zone then re-entering it toward the end of the reporting period. Inflows to the project during September, March, April, May, June and July were 426 percent, 29 per cent, 11 percent, 41 percent, 41 percent, and 72 percent of average respectively.

Gated releases were made on November 6-14. No flood control was achieved during this period.

Maximums of Record:

Daily Inflow-Date Daily Qutflow-Date

Highest 345 cfs Jun 15 80 152 cfs Jun 18 84 2nd 344 cfs Mar 02 79 145 cfs Jun 19 84 3rd 301 cfs Jun 16 84 144 cfs Jun 17 84

Pool-Date

Highest 1124.4 Jun 17 84 2nd 1123.7 Jun 15 80 3rd 1123.2 Mar 03 79

Minimums of Record (since initial fill):

Pool-Date

Lowest 1119.5 Nov 15 89 2nd 1120.5 Jul 17 81

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Qutflow (AF)

3342, 55 % of normal 1857, 31% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

220, Sep 4 47, Sep 9

Peak Pool Elevation (Ft. MSL) Minimum Pool Eleyation (Ft. MSL)

1121.1, Sep 5 1119.5, Nov 15

-~-~------c----:-....,------;------c-----.,------. . ·'•' :.. • GLENN CUNNINGHAM DAM AND LAKE PAPILLION CREEK BASIN - NO. 11, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 1132 1 I I I I I I I f I {T0P 0~ FL~OD ~ ONTR OL ZONE EL 1142)

1130

. 1128 _J. U1. ~ 1126 t- w w LL.. .. 1124 z 0 t- I lk II A Jl <( 1122 > r\ l,/ w --~~ ~\~ v_~ --\j.J\ W_~ f\ r------~ ~ f-yl _J ~ ~ [V' w ~ ~ ~- l(; v 1120 r\ 1..-- '/ L ,_ v v

1118 _TOP OF MU(TIPURPOSE 1--1-- ZONE (EL 1121 )

1116 I I I 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I STANDING BEAR DAM AND LAKE PAPILLION CREEK BASIN - NO. 16, NEBRASKA 1989-1990 REGULATION

The pool level remained below the flood control zone during the entire report period. Heavy precipitation during September and July caused slight rises in the pool level. Precipitation during March, May and July caused some fluctuation within the pool level. Inflows to the project during September, March, May and July were 107 percent, 11 percent, 13 percent and 103 percent of average respectively. No flood control was achieved during this period.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 266 cfs Jun 14 84 65 cfs Jun 16-17 84 2nd 235 cfs Aug 09 87 64 cfs Jun 15 84 3rd 180 cfs Jun 17 83 57 cfs Aug 09 87

Pool-Date

I Highest 1107.8 Jan 16 84 2nd 1107.1 Aug 08 87 ~ 3rd 1106.8 May 21 82

Minimums of Record (since initial fill):

Pool-Date

Lowest 1097.6 May 22 90 2nd 1098. 3 Feb 11 82

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

208, 19% of normal 0

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

22, Sep 8 0 Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

1100.0, Sep 9 1097.6, May 22 STANDING BEAR DAM AND LAKE PAPILLION CREEK BASIN - NO. 16, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 1112 1 I I I I I I I I I (T0P 0~ FLdoo CONTR OL ZONE EL 1121)

1110

1108 _j. U'). ~ 1106 1-w I w flo, ,. l , L.&.. 11 04 .U "'- .r '~ z ~ v \[ TOP OF MULTIPURPOSE \t ZONE (EL 1104) 0 \ \ '\ vl ~ 1102 \ ~ >w \ __J 1100 1\ w l'l \ ~ ~. ~ ~ If' I"- ~ r.. t-"1 I'-- .,..... 1098 !---. f-.1 J N

1096 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS REPORT PERIOD ZORINSKY DAM AND LAKE PAPILLION CREEK BASIN - NO. 18, NEBRASKA 1989-1990 REGULATION

On December 7, 1989, the low level gate was closed and filling began. Due to drought conditions prior to and after the closing, the reservoir level has risen relatively slowly. Only one summer storm provided significant inflow to the project. After this event, the pool rose approximately nine feet, but there is still twenty feet until the top of multipurpose pool is reached. A data collection platform has been installed at the site, however, it has not been activated because the pool has not reached the orifice elevation. It is anticipated that once the pool exceeds elevation 1100, the DCP will be brought on line. Several site visits were made in the summer of 1989, and the pool elevations were noted. The levels were recorded from a staff gage placed near the outlet works at the project. The readings from the site visits are show below:

* December 7 1077.0 ft MSL August 17 1099.5 September 11 1098.8 September 20 1098.5

October 29 1097.9 I ~ * invert of low level gated outlet

I t PAPILLION CREEK BASIN - NO. 18, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

I I 1 1 _I I I I I I TOP OF FL00D CONTROL ZONE (EL 1128.2) 1128 ------

. 1124 _j (/). ~ 1120 1- w w LOW LEVEL GATE (EL 1 090) OPEN La... I z 1116 0 I- < > ~ 1112 w TOP OF MULTIPURPOSE ZONE (EL 111 0) ------

1108

1104 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS REPORT PERIOD WEHRSPANN DAM AND LAKE PAPILLION CREEK BASIN • 20, NEBRASKA 1989-1990 REGULATION

During the reporting period the level remained below the flood control zone. Heavy precipitation during September and July caused high rises in the pool level. Some fluctu.tion occurred during the months of March, May and June in the pool level because of precipitation. Inflow to the project during September, Karch, May, June and July were 147 percent, 38 percent, 42 percent, 125 percent, and 257 percent of average, respectively. No flood eontxal was achieved during this period.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 515 cfs Aug 25 87 77 cfs Aug 26 87 2nd 285 cfs Oct 11 86 28 cfs Jun 09 87 May 26 87 3rd 171 cfs Jul 12 86 22 cfs Sep 01 87

Pool-Date

Highest 1099.5 Aug 25 87 2nd 1096.7 May 27 87 3rd 1096.1 Jun 08 87

Minimums of Record (since initial fill):

Pool-Date

Lowest 1085.4 May 02 90 2nd 1086.9 Jun 01 89

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF>

1101, 89 % of normal 0

Peak D§ily Inflow (CFS) Peak DAily Qutflow (CFS)

167, Jul 26 0, Jul 26

~eak Pool Elevation (Ft. MSL) Minimum Pool Elevation ([t, MSL)

1089.6, Jul 26 1085.4, May 2 WEHRSPANN DAM AND LAKE PAPILLION CREEK BASIN - 20, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

1104 I I I I 1 1 1 r r r 1 r r (TOP OF FLOOD CO NTR OL ZONE EL 1113.1)

1100 . _J . 1096 ------"l·\ ------(/). TOP OF MULTIPURPOSE :::E ZONE (EL 1095.8) 1- J w 1092 1\ w l..&... .. 1'- z \ L 0 1088 1\ !"-.. ~~\ \ ~ 1- ~ I'-- ,__ <( ...... ,r-. :;-1'1 > v-r w "'"' d 1084 r I

1080

1076 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS REPORT PERIOD PIPESTEM DAM AND LAKE PIPESTEM CREEK, JAMES RIVER BASIN, NORTH DAKOTA 1989-1990 REGULATION

Beginning on November 9, 1989 and ending December 10, 710 acre-feet of water stored in the flood control zone was released from the reservoir prior to winter freeze-up. The gates remained closed the spring and summer of 1990 as below normal runoff precluded the necessity for any gated release.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 3,380 cfs Apr 20 75 310 cfs Oct 22-26, 31 Nov 1 75 2nd 3,000 cfs Apr 18 79 250 cfs Apr 10-12 76 3rd 1,945 cfs Mar OS 83 200 cfs Apr 26-29 79 Aug 30-Nov 12 79 200 cfs Apr 6-9 84 200 cfs Apr 7-15 88 Pool-Date

Highest 1468.35 May 10 79 2nd 1466.28 Apr 15 87 3rd 1466.06 Jul 17 75

Minimums of Record (since initial fills):

Pool Date

Lowest 1439.97 Jan 1 77 2nd 1440.50 Feb 9-10 75

Maximum Combined Discharge (Pipestem & Jamestown)

Combined Pipestem Jamestown Date

Highest 489 cfs 0 489 cfs Apr 16. 83 2nd 488 cfs 150 cfs 338 cfs Apr 28 75 3rd 475 cfs 125 cfs 350 cfs May 31 - Jun 8 74 4th 470 cfs 100 cfs 370 cfs Apr 15-19 87

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

3852, 15% of normal 710, 3% of normal

Peat Daily Inflow (CFS) Peak Daily Outflow (CFS)

105, Jun 4 28, Nov 10

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

1443.41, Nov 9 1442.00, Aug 17 PIPESTEM DAM AND LAKE PIPESTEM CREEK, JAMES RIVER BASIN, NORTH DAKOTA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 1475 1 I I I I I I I I I (TbP OF FLobo CO NTR OL ZONE EL 1496.3)

1470

. 1465 _j (/) ~ 1460 \ 1-- w w ~ LL 1455 1\ A z I 0 ~ 1450 >w _j w 1445 t 1-- ~ h.- J --- ~--"~~~- ~~ v V- ~ -- ~ r:.- 1440 TOP OF MULTIPURPOsE ZONE (EL 1442.4) -

1435 I I I I I I I I 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I OLIVE CREEK DAM AND lAKE SALT CREEK BASIN - NO. 2, NEBRASKA 1989-1990 REGULATION

Below average precipitation throughout the period caused the pool level to remain below the flood storage zone during the period. High rises occurred in the pool level during the month of September and slight rises occurred in July due to heavy rainfall totals of 5.64 inches in September and 4.21 inches during July. Inflows during September and July were 321 percent and 30 percent of average, respectively. No flood control was achieved during the period.

Maximums of Record:

Daily Inflow-Date Daily Outflow Date

Highest 764 cfs Jun 12 84 176 cfs Oct 12 73 2nd 749 cfs Oct 10 73 171 cfs Jun 13 84 3rd 730 cfs Oct 11 86 145 cfs Oct 12 87

Pool-Date

Highest 1342.6 Oct 11 73 2nd 1342.6 Jun 12 84 3rd 1341.3 Oct 11 86

Minimums of Record (since initial fill:)

Pool-Date

Lowest 1328.1 Aug 08 71 2nd 1329.6 Jun 21 89

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

523, 25% of normal 0

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

50, Sep 8 0

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

1332.3, Sep 9 1329.6, Aug 18 OLIVE CREEK DAM AND LAKE SALT CREEK BASIN - NO. 2, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

1344 I I I I I I I I I I I I I (TOP OF FLOOD CONTR OL ZONE EL 1350)

1342

• 1340 .....J. (/). ~ 1338 1- w w u.. 1336 -TOP OF SEDIMENT POOL - f-- .. ZONE (EL 1335} z ---- - 0 ~~-- N-- - M------~ 1334 \ \ \ \ \ \ ~ 'fl. >w ~ ~ .....J \ w 1332 \ ""'-., \ " r---.. r- \ - 1'-- v-- "-.., r-- \ ~ 1330 \l N ~\ ['..

1328 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS REPORT PERIOD BLUESTEM DAM AND LAKE SALT CREEK BASIN • NO. 4, NEBRASKA 1989-1990 REGULATION

The pool level remained below the flood control zone through the reporting period even with brief periods of heavy rain fall that occurred during the month of September that totaled 6.l9 inches, and 4.37 inches in May. Precipitation in September caused the pool level to come within .6 feet from entering the flood control zone. The pool level continued downward from that period until Kay when a slight rise occurred and then started dropping again during July. Inflow to the project during September and May were 452 percent and 21 percent of average respectively. Gated releases were made on October 25·30.

Maximums of Record:

Daily Inflow-Date Daily Qutflow-Date

Highest 1,447 cfs Oct 10 73 342 cfs Oct 12 73 2nd 911 cfs Oct 11 86 198 cfs Jun 13 84 3rd 908 cfs Jun 13 84 139 cfs Oct 12 86

Pool·Date

Highest 1316.5 Oct 11 73 2nd 1314.5 Jun 13 84 3rd 1312.5 Oct 11 86

Minimums of Record (since initial fill):

Pool·Date

Lowest 1299.9 Sep 1 77 2nd 1301.8 Sep 21 81

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow CAf) Total Outflow (AF)

1862, 46 % of normal 111, 4% of normal

Petk Daily Inflow (CFS) Peak Daily Outflow (CFS)

270, Sep 8 21, Oct 26

Petk Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

1306.8, Sep 15 1302 . 2, Aug 20 BLUESTEM DAM AND LAKE SALT CREEK BASIN - NO. 4, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

1316 I I I I I I I I I I I I I (TOP OF FLOOD CO NTR OL ZONE EL 1322.5)

1314

• 1312 _J. Vl. ::E 1310 1-w w LL.. 1308 .Jl ~ TOP OF CONSERVATION .. ____ZC?~E- (_E_ L _! 39~ ._4 )_ __ z ---- ~-- -- - ~ ------0 -\ I ~~ A l\ 1\ ~ 1306 \ \ \ J !'.... ~ 1'-, > \. 1\ "¥- w ""'-...... , _J v- ' - V' ~ r w 1304 \ \ L'Y ~ 1\~ \~ 1302 ""

1300 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I WAGON TRAIN DAM AND LAKE SALT CREEK BASIN - NO. 8, NEBRASKA 1989-1990 REGULATION

The pool level entered the flood control zone during the month of September due to heavy precipitation which caused a high rise in the pool level and established a new third high maximum of record. The pool level dropped below the flood control zone in October and remained throughout the period. The pool level fluctuated some during March through June and started to decline again in July. Heavy rain fall of 7.09 inches in September and 5.72 inches during July produced inflows to the project of 867 percent and 29 percent of average respectively. Gated releases were made during the end of October.

Maximums of Record: I Daily Inflow-Date Daily Outflow-Date • • Highest 1,199 cfs Oct 10 73 329 cfs Oct 12 73 • 2nd 1,027 cfs Oct 11 86 175 cfs Oct 12 86 • I 3rd 874 cfs Sep 08 89 170 cfs Jun 14 84 • Pool-Date

Highest 1295.4 Oct 11 73 2nd 1293.2 Jun 13 84 I Oct 11 86 3rd 1292.8 Sep 09 89 f 1 Minimums of Record (since initial fill): Pool-Date ~ Lowest 1282.2 Nov 28 75 2nd 1284.6 Oct 21 81

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Qutflow CAF)

2811, 67% of normal 1737, 56% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

874, Sep 8 72, Sep 9

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

1292.8, Sep 9 1285.3, Jul 24

,,~--~--~

r ... :1 ·. ~ ,o WAGON TRAIN DAM AND LAKE SALT CREEK BASIN - NO. 8, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 1298 1 1 (T0P 0~ FL~OD CONTR -'o~ zoNk EL 13b2) I

1296

• 1294 .....J. (/). ::E 1292 1- w w u.. 1290 .. TOP OF CONSERVATION- z ZONE (EL 1287.8) 0 [...)./ 1288 II ~~ ll ~l \ v ~ ---- -~ ~ ------n - - lt - ~ -R w> .....J \ ~ '\...... w 1286 \ r\ --'- \ t"\f ~ f"J 1284

1282 80 81 82 83 84 85 86 87 88 89 ASONDJFMAMJJ 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I STAGECOACH DAM AND LAKE SALT CREEK BASIN - NO. 9, NEBRASKA 1989-1990 REGULATION

Due to heavy rain fall in September the pool level entered the flood control zone and produced a highrise in the pool level. The pool level reclined below the flood control zone at the end of September and remained throughout the reporting period. Inflow to the project during September was 701 percent of average respectively. Gated releases were aade during October 25-31 and Hov.-ber 1-2. During the summer of 1990, the Nebraska Game and Parks Commission requested that the lake level be lowered 10 feet to allow construction of islands in the upper end of the lake. The lake level was reduced from 1271.0 ft MSL t~ 1261.3 ft MSL. The low level gate was opened on June 4 and will remain open until the spring of 1991. The pool level set a new minimum second low. No flood control was achieved during this period.

Maximums of Record:

Daily Inflow-Pate Daily Outflow-Date

Highest 958 cfs Oct 10 73 190 cfs Oct 12 73 2nd 829 cfs Oct 11 86 116 cfs Oct 12 86 3rd 482 cfs Jun 12 84 109 cfs Jun 14 84 Pool-Date , Highest 1279.0 Oct 11 73 2nd 1277.4 Oct 11 86 1 3rd 1217 .1 Jun 13 84

Minimums of Record (since initial fill):

fool-Date

Lowest 1260.5 Aug 09 76 2nd 1261.3 Jul 22 90

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow Total Qutflow (AF)

1105. 65 ' of normal 2129, lllt of normal

Peat Daily Inflow CCFS) Peak Daily Outflow (CFS)

275. Sep 8 69, Sep 9

Peak P0ol Elevation CFt. MSL) Minimum fool Elevation (Ft. MSL) 1273.7, Sep 8 1261.3, Jul 22 STAGECOACH DAM AND LAKE SALT CREEK BASIN - NO. 9, NEBRASKA 1989-1990 REGULATION

A 10-year paol elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

1282 I I _I I I I I I I I I I I (TOP OF FLOOD CONTR OL ZONE EL 1285) 1280

1278

_j. 1276 (/) TOP OF SEDIMENT POOL . ZONE (EL 1271.1) :::E 1274 1- v tj 1272 I I I LL.. ~ll WJ~ ~- ~- r:.; ~ -1-J ------"" bi, ~ ~ rl _. 1--- ~ z 1270 ~ hr' ~ 0 1.- r-~ 1-" 1- <( 1268 w> d 1266

1264

1262 \ ,J' 1260 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I YANKEE HILL DAM AND LAKE SALT CREEK BASIN - NO. 10. NEBRASU 1989-1990 REGULATION

Heavy rainfall during Septeaber caused a high rise in the pool level which caused the pool level to enter the flood control zone and stayed until the end of October. The inflow to the project during September was 846 percent of average respectively. The pool level receded below tbe flood control aone during Noveaber and stayed until Hay when it re-entered the flood control zone and fluctuated above and below due to precipitaton throughout the period. The inflow set a new second maximum of record.

Maximums of Record:

Paily Inflow-Date Qaily Qutflow-Date

Highest 690 cfs Oct 10 73 145 cfs Oct 12 73 2nd 575 cfs Sep 08 89 114 cfs Jun 14 84 3rd 538 cfs Oct 11 86 100 cfs Mar 25 87

Pool-Date

Highest 1252.3 Oct 11 73 2nd 1250.7 Jun 13 84 3rd 1250.0 Mar 25 87 Minimums of Record (since initial fill): Pool-Date

Lowest 1238.9 Aug 08 77 2nd 1239.1 Sep 19 81

Report Period: (August l, 1989 through July 31, 1990)

Total Inflow CAf) Total Qutflow CAF) 3181, 65\ of normal 1757, 43% of normal

Pe§t Paily Inflow CCFS) Peak Daily Outflow CCFS)

575. Sep 8 77, Sep 9

Peak Pool Eleyation

1248.2. Sep 8 1241.6, Aug 19 YANKEE HILL DAM AND LAKE SALT CREEK BASIN - NO. 1O. NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

1254 I I I I I I I I I I I doP JF FLbOD CONTROL ZONE EL 1262)

1252

• 1250 .....J. (/). :::!: 1248 f- TOP OF CONSERVATION UJ UJ ZONE (EL 1244.9) L.a.. 1246 II II v .. \ v z ~ ~ _, ;. 0 ~~------~ -- _f:: -- --~ ----1 ~ f-. r-:. wM --\- --\ 8J r1-- ""'- lr lJ- ~ 1244 v > UJ .....J ~ UJ 1242 ~ t\~ \ ~ 1'-r

1240 1\ ~ ~

1238 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I CONESTOGA DAM AND LAKE SALT CREEK BASIN - NO. 12, NEBRASKA 1989-1990 REGULATION

Heavy rainfall during September, May, June and July (8.86 inches, 5.06 inches, 4.05 inches and 5.48 inches respectively, at the dam site) caused the high rises in the pool level. The pool level entered the flood control zone in September and receeded below this level at the end of the month and stayed until the end of July when it re-entered the flood control zone and stayed throughout the period. Inflow to the project during September, May, June and July were 652 percent, 18 percent, 15 percent and 158 percent of average respectively. Gated releases were made on October 23-30. No flood control was achieved during this period.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 907 cfs Mar 24 87 185 cfs Mar 25 87 2nd 661 cfs Jun 27 83 152 cfs Jun 16 82 3rd 620 cfs Jun 15 82 51 cfs Oct 12 73

Pool-Date

Highest 1241.1 Mar 24 87 2nd 1239.6 Oct 11 73 3rd 1238.3 Jun 15 82

Minimums of Record (since initial fill):

Pool-Date

Lowest 1228.4 Aug 28 77 2nd 1230.0 Jul 30 81

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow CAF) Total Outflow CAF)

3005, 49% of normal 1876, 35% of normal

Peak Daily Inflow CCFS) Peak Daily Outflow CCFS)

546, Sep 8 105, Sep 9

Peak Pool Elevation

1235.6, Sep 8 1230.3, Nov 28

• • l ' CONESTOGA DAM AND LAKE SALT CREEK BASIN - NO. 12, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 1244 (TbP oJ FLobo C~NTRbL ZONE EL 1252) 1242

. 1240 .....J. (/). ~ 1238 1-- w w La.. 1236 z ~ 0 TOP OF SEDIMENT POOL ZONE (EL 1232.9} ~ 1234 I / > ~ / w ---- ~-~------!.. ------.....J -\ ~vv ~-v ---v ~ ~~ \-- \~ w 1232 ~ fJ '\, \ ~ --. N ~ lr r 1230 h ""'

1228 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I TWIN LAltES DAM AND lAKE SAt.'l' Clli!:EK BASIN · NO. 13, NEBRASKA 1989·1990 REGULATION

The pool level remained below the flood control zone throughout the reportlns ,er1od. Heavy rainfall in September and July of 7.95 inches and G.05 inchea at the dam slte eauaed high r1aes within the pool level. Inflow to the ,roject clurift! S•pteaber and July were 215 percent and 94 ~rcent of a~erage t'ea,eotlv.ly. Gated releaaes were aade on September 8 ·18 . No flood control was achieved during the period.

Maxl~s of Record: Daily Inflow·Pate Daily Qutflow·Date

Highest 539 efs Mar 23 87 168 cfs Jun 30 83 2nd 507 cfs Jun 28 83 167 cfs Mar 24 87 lrcl 476 cfs Jun 12 84 162 cfs May 20 84

Pool-Date

Hi~hest 1346.9 Jun 29 83 2nd 1346.0 Mar 23 87 lrcl 1344.6 Kay 19 84

Minimums of Re~ord:

Pool·Date Lowest 1332.2 Aug 18 89 2nd 1336.3 Jul 29 81 Aug 29 77

Report Period: (August 1, 1989 through July 31, 1990) Total Igflow CAF) total Qutf1ow CAF)

860, 2lt of normal 121, 4\ of normal

bak, l>aily Inflow CCF$) !et.k Daily Outflow CCFS)

151, Sep 8 17, Sep 9

!eak bml Elevation CFt. MSL) M1nillUpl. Pool Elevation !Ft. MSL) 1334.7, Sep 8 U32.2, Aug 18 TWIN LAKES DAM AND LAKE SALT CREEK BASIN - NO. 13, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 1348 I I I I I I I I I I I dop ~F FLbOD CONTROL ZONE EL 1355)

1346

• 1344 .....J. (/). ~ 1342 t-- TOP OF CONSERVATION - 1- II. ZONE {EL 1341) w ~ ------~ -1-- ~~ J_ ~- -~ ~------w ' LL.... 1340 v v z 0 ~ 1338 w> .....J \ w 1336 ~

1334 L ----- "v-. \\ /""" r---. r f-.r" 1332 rv "" 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS REPORT PERIOD

' PAWNEE DAM AND LAKE SALT CREEK BASIN - NO. 14, NEBRASKA 1989-1990 REGULATION

Precipitation that amounted to 8.44 inches in September and 8.15 inches d.uring. July caused the pool level to enter the flood control zone and produce hish rises within the pool lavel. The pool level droppe.d below the flood control z:one in October and stayed toward the end of July when it re-entered the flood control zo.ne and stayed to the end of the reporting period. Inflow to the projeet during September and July were 354 percent and 199 percent of average respectively. Gate releases were made on October 23-31 and 26 thru 30 July. No flood control was achieved during this period.

Maximums of Record: 4 Paily In£low-Date Daily Qutflow-Pate

Highest 1,381 cfs Mar 24 87 419 cfs Mar 25,26 87 2nd 1,074 cfs Ju1 19 85 311 cfs Jun 13 84 lrd 901 cfs Ju1 01 86 294 cfs Ju1 01 86

Pool-Date

Highest 1248.4 Mar 24.25,27 2nd 1247.1 Jun 12 84 lrd 1246.8 Jul 01 86

Minimums of Record (since initial fill):

Lowest 1240.2 Oct 14 79 2nd 1241.2 Jan 01 77

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (A[} Total Outflow CAfl

4933, 63% of normal 1658. 32., of normal

Peak Daily Inflow CCFS) Peak Daily Outflow (CF$)

454, Sep 8 43, Sep 10

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation CFt. .MSL)

1245.2, Sep 9 1241.8, Nov 27 PAWNEE DAM AND LAKE SALT CREEK BASIN - NO. 14, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

1252 I I f I I I I I I I I I I (TOP OF FLOOD CO NTR OL ZONE EL 1263.5)

1250

• 1248 .....J. (/'}. ~ 1246 ~ TOP OF SEDIMENT POOL - ZONE (EL 1244.3) 1-w w ~ u ~~ ;v A-- -.Ji-- ~~-~~~ --\!- -- -\r- J ~ J~~ -- lA------~ ------u.... 1244 y\. z ~'tv \.r ~ 1- 0 \ r--- .r I~ ~ 1242 lr' >w .....J w 1240

1238

1236 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS I REPORT PERIOD I ANTELOPE CREEK DAM AND HOUIES PARK lAKE SALT CREEK BASIN~ NO. 17, NEBRASKA 1989-1990 REGULATION

Inflow during August, September and July were caused by heavy precipitation. The pool level entered the flood control zone in August and fluctuated within the zone until mid September when it receded below the flood control zone and stayed toward the end of July then re-entered the flood control zone and stayed to the end of the reporting period. High rises occurred within the pool level during September and July. Inflow to the project during August, September and July were 297 percent, 720 percent and 430 percent of average respectively. Gated releases were made on August 28-29. No flood control was achieved during this period.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 567 cfs Sep 08 89 187 cfs Jun 29 83 2nd 401 cfs Jun 27 83 140 cfs Sep 09 89 3rd 381 cfs Jun 27 83 134 cfs Kay 25 84

Pool-Date

Highest 1249.1 Sep 08 89 2nd 1248.1 Jun 27 83 3rd 1247.9 Oct 11 86

Minimums of Record (since initial fill):

Pool-Date

Lowest 1232.9 Aug 3 77 2nd 1236.8 Feb 26 76

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Qutflow

3144, 163% of normal 2478, 183% of normal

Peak Daily Inflow CCFS) Peak Daily Qutflow (CFS)

567, Sep 8 140, Sep 9

Peat Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

1249.1, Sep 8 1240.3, Apr 30 ANTELOPE CREEK DAM AND HOLMES PARK LAKE SALT CREEK BASIN - NO. 17, NEBRASKA 1989-1990 REGULATION

A 1 0-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

1252 I I I I I I I I I I I I (TOP OF FLOOD CONTR OL ZONE EL 1266)

1250 t

• 1248 .....J. (/). ::IE 1246 I-w w TOP OF CONSERVATION LL. 1244 t-- .. r- ZONE {E~ 1242.4) - z 0 --- ~ --It - -~ ~ ------i! ------~ 1242 N~- 1111 ~ -~ I" ' > II 'If w ~ 1\ ~ \ 1\ " I'1"-- ~ ~ .....J M~, 1--r... ~ I-N ~ v w 1240 1\ ~ 1238

1236 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I BRANCHED OAK DAl'f AND LAKE SALT CREEK BASIN - NO. 18, NEBRASKA 198~-1~9~ REGULATION

Heavy preeipitation during September, May and July (7. 78 inches, 5.15 im:l'le-.s au 7.04 btehes at 1the· c!lam site} caused high rises and some fluetuation in 1tlile pool lr«el. The pc~o-l level entered tlte fleod control zone in Septemher aJDd receG!ed below the flood eofttro-l zone in Octobe·r and remained: 1throughout 1the :reywrti.ng period'. Inflow to tile project during September, l!lay and July were 337 pereent:, 2' pereent, and 74 pereent of average respectively. Gated rele-ases were aaclie durbtg At1gust li-22, October 23-:n, November 1-9, June 26-30, and July 1-20'. No flood control was achieved during this period.

Maximums of Record: Daily Inflow-Date Daily Outflow-Date • Highest 3, 700 cfs Aug 25 87 730 cfs Aug 26 87 2nd 2,435 cfs Mar 23 87 670 cfs Jun 19 83 3rdi 1,780 cfs Jun 18 83 667 cfs Mar 24 87

Pool-Date

Highest 1287.9 Aug 26 87 2nd 1287.7 .Jun 18 83 Mar 23 87 3rd 1287.2 Jun 13 84

Minimum of Record (since initial fill):

Pool-Date

Lowest 1280.9 Jan 1 77 2nd 1281.5 Nov 25 89

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

11720, 41% of normal 7196, 32% of normal

Peak Daily Inflow (CFS.) Peak Daily Outflow (CFS)

1165, Sep 8 106, Sep 10

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

1285.1, Sep 9 1281.5, Nov 25 BRANCHED OAK DAM AND LAKE SALT CREEK BASIN - NO. 18, NEBRASKA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

1294 1 1 (TOP OF FLOOD CONTR'o~ ZONE EL 1311) '

1292

• 1290 .....1. (/). ~ 1288 1- w w TOP OF CONSERVATION I..L... 1286 ZONE {EL 1284) z / 0 v ~ j? ~ 1284 >w .....1 "-- v-.,

~ w 1282 ~ v ~ I~ - _,../ f--

1280

1278 80 81 82 83 84 85 86 87 88 89 A S 0 N 0 J F M A M J J 1989 1990 CALENDAR YEARS REPORT PERIOD SNAKE CREEK DAM AND LAKE AUDUBON LAKE SAKAKAWEA SUBIMPOUNDMENT MISSOURI RIVER BASIN, NORTH DAKOTA 1989-1990 REGULATION

Lake Audubon is a subimpoundaent of Garrison Reservoir and is located 8 miles northeast of Riverdale, North Dakota. The embankment, known as "Snake Creek•, has a crest elevation of 1865 ft. MSL. At the original planned operating level of 1850 ft. MSL., Lake Audubon would cover 20,600 acres and contains 396,000 AF of water.

The embankment was constructed with the primary purpose of relocating U.S. Highway 83 and the Soo Line Railroad across the Snake Creek Arm of the Garrison Diversion. In addition, during the planning stage it was decided to create a gated subimpoundment for the dual purpose of fish and wildlife en hancement, and the future diversion of water for anticipated irrigation. The pool level has been kept below elevation 1850 because (1) all land surrounding • the lake has not been acquired to maintain the 1850 level and (2) that level (head) is not needed to supply water to the revised lower irrigation acreage. Garrison pool levels are limited to less than 15 feet above the Audubon pool for dam safety consideration. Most of the time, however, the Lake Audubon level is higher than the Garrison pool. If the latter condition exists, the Snake Creek pumping plant, operated by the Bureau, is used to transfer water from Garrison Reservoir to Lake Audubon. Gravity flow discharge to or from Lake Audubon is conveyed by a gated conduit 7 feet wide by 10 feet high with invert elevation at 1810 ft. MSL. This gated conduit is normally closed.

Lake Audubon was operated in accordance with the 1987 Letter of Under I standing between the Corps, the Bureau of Reclamation, Fish and Wildlife 1 Service, and the North Dakota Game and Fish Department. During the fall and winter months, the lake level receded to elevation 1846 due to releases down the McClusky Canal and evaporation. Beginning on April 5 and continuing in termittently through the spring, water was pumped into Lake Audubon from Lake Sakakawea. The pool was maintained as close to the target pool of 1847.5 as possible.

Maximums of Record: Minimums of Record:

Pool-Date Pool-Date

Highest 1848.61 Apr 26 76 Lowest 1843.39 Mar 13 85 2nd 1848.57 May 21 79 2nd 1844.02 Mar 29 88

Report Period: (August 1, 1989 through July 31, 1990)

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation

1847.32, Jun 29 1844.87, Apr 5 SNAKE CREEK DAM AND LAKE AUDUBON LAKE SAKAKAWEA SUBIMPOUNDMENT MISSOURI RIVER BASIN, NORTH DAKOTA 1989-1990 REGULATION A 1 0-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 1851

I I I I I I I I ·~ I I OP ~~ATJNG POO_L {EL 1850) 1850 ------LLNtJ------

• 1849 .....J. (/) TARGET POOL FOR FISH AND . _j __ A WIL DLIFE {PRESENTLY EL 1847.5) ~ 1848 _,... -..... ------1- ~~ w v~ ~~ ------I~ ------w ll~ ~ " ~-- ~ LL. 1847 ~ 11M ~ J" N .. ~ \ z • 0 1\ I\ ~ 1846 ~~ 1'1 "r'- >w f"- .....J "~ 1- w 1845 r\ ~

1844

1843 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I SPRING CREEK DAM AND LAKE POCASSE (I...AKE OAHE SUBIMPOUNDMENT) MISSOURI RIVER BASIN, SOUTH DAKOTA 1989-1990 REGULATION

Lake Pocasse is operated and administered as the Pocasse National Wildlife Refuge by the Department of the Interior's Fish and Wildlife Service under an agreement with the Corps of Engineers. The pool levels of Oahe Reservoir and Lake Pocasse are contiguous at or above elevation 1617.00 ft. MSL, the top of the annual flood control and multiple use zone in Lake Oahe. The long-term plan of regulation is to maintain the Lake Pocasse level as high as possible. Every 4 or 5 years, an early summer drawdown to elevation 1614 ft. MSL will assist in the re-establishment of shoreline vegetation and improved water quality. In addition, upon evaluation of hydrologic conditions prior to the spring runoff each year above Pocasse, decisions may be made by the Section to lower the pool to accommodate the appropriate runoff volumes.

Maximums of Record:

Pool Date

Highest 1625.00 Mar 23 87 2nd 1621.20 Mar 19 78 3rd 1620.52 Mar 19 72

Minimums of Record (since initial fill):

Lowest 1609.10 Dec 7 21 2nd 1610.52 Jul 30, 31 88

Report Period: (August 1, 1989 through July 31, 1990)

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

1616.13, Aug 5 1613.75, Jul 31 SPRING CREEK DAM AND LAKE POCASSE (LAKE OAHE SUBIMPOUNDMENT) MISSOURI RIVER BASIN, SOUTH DAKOTA 1989-1990 REGULATION A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 1626 I TOP OF DAM CEL 1S2S) I ------1624

1622

0 .....1. V'! 1620 :2: l 'll ~ t!:l1618 v -SPILLWAY CREST u.. (EL 1617) ------_, ------~ -\-- -r\- ~- -~- -~- 5 1616 \r-JiJ ""j -...... \t ~ 1- \ t----,..."'

1610 \ \

1608 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I NON-CORPS PROJECTS

Regulated for flood control according to regulations in the Federal Register and supplemental agreements (between the Bureau of Reclamation and Corps of Engineers), in compfiance with the 1944 Flood Control Act.

BOYSEN DAM CANYON FERRY DAM CLARK CANYON DAM GLENDO DAM HEART BUTTE DAM JAMESTOWN DAM KEYHOLE DAM PACTOLA DAM SHADEHILL DAM TIBER DAM '-- YELLOWTAIL DAM BOYSEN DAM AND LAKE BIGHORN RIVER BASIN, WYOMING 1989-1990 REGULATION

Boysen Reservoir is regulated by the Bureau of Reclamation (Regional Director) except when the pool level rises into the exclusive flood control zone as per the Field Working Agreement dated May 5, 1967. When this occurs release determination is the responsibility of the Corps of Engineers (Dis trict Engineer).

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 19,253 cfs Jun 23 67 14,204 cfs Jul 7 67 2nd 17,975 cfs Jun 17 63 8,518 cfs Jun 24 63 3rd 15,780 cfs Jun 8 57 8,146 cfs Jun 30 71

Pool-Date

Highest 4730.83 Jul 6 67 2nd 4729.85 Jul 5 57 3rd 4727.89 Jul 4 83

Minimums of Record (since initial fill):

Pool-Date

Lowest 4684.18 Mar 18-19 56 2nd 4686.42 Sep 21 60

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

675,040, 65% of normal 748,010, 72% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

4709, Jun 12 1481, Jun 3

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

4718.99, Aug 1 4710.01, Jun 5 BOYSEN DAM AND LAKE BIGHORN RIVER BASIN, WYOMING 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 4735 1 1 ~OP JF FLI000 ------~~~!~~lj~~~_ c~(_1~~¥~1t __ 4730

TO P OF JOINT USE ZONE (EL 4725) ~ 4725 (/). ~ ~ A I T~P loJ cbN~ElvlTIIoJ ~ ZONE (E~ 4717) ~ 4720 \ LLJ " ["\ u... __ !~ .. - -- ,------~ t-:' ~ ------z -\ ~ 0 4715 \ ;::: ~· [\ ry < 1\ \ > ...... __ LLJ \ 1\ \ ..._j d 4710 1\ ~ v 1\ J v :~ 4705 v

4700 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I

' . CANYON FERRY DAM AND RESERVOIR MISSOURI RIVER BASIN, MONTANNA 1989-1990 REGULATION

Canyon Ferry Reservoir is regulated by the Bureau (Regional Director) except when the pool level rises into the exclusive flood control zone or that portion of the joint use (conservation-flood control) zone required for flood control, as per the Field Working Agreement dated May 23, 1977. When this occurs, release determination is the responsibility of the Corps (District Engineer).

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 29,050 cfs May 24 81 25' 720 cfs Jun 13 81 2nd 27,570 cfs Jun 19 74 24,370 cfs Jun 19 64 3rd 27' 110 cfs May 30 56 24,030 cfs May 31 56

Pool-Date

Highest 3800.00 55,56,62 2nd 3799.93 Jul 7-12 75 3rd 3799.66 Jun 4-5 62

Minimums of Record (since initial fill):

Pool-Date

Lowest 3764.70 Apr 11 67 2nd 3772.75 Mar 25 62

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

2,755,500, 68% of normal 2,476,917, 60% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

11,748, Jun 13 5,323, Feb 28

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

3794.37, Jul 8 3777.79, Apr 3 CANYON FERRY DAM AND RESERVOIR MISSOURI RIVER BASIN, MONTANA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 3805

TOP OF FLO OD CONTROL ZONE {EL 3800) 3800 ------I I I I I I I I I I I I p 0 ------ti------T~ F_ ~.QI~_l~ -~?;_ ~-Q~;- {;_L_ -~?~?)_ __ ~ 3795 en. r' ::E ~ A /\ ~ 3790 w LL.. u .. 1/ ~ ~ 3785 Av 5 W'' \ ~ <( ------V- ~ ------> \II 1 w vl IW u i\ - v d 3780 1\ 1/ ~ i) BASE OF REPLACEMENT ZONE (EL 3783) 3775 v

3770 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I CLARK CANYON DAM AND RESERVOIR BEAVERHEAD RIVER BASIN, MONTANA 1989-1990 REGULATION

Clark Canyon Reservoir (Hap Hawkins Lake) is regulated by the Bureau (Regional Director) except when the pool level rises into the exclusive flood control zone or that portion of the joint use (conservation-flood control) zone required for flood control, as per the Field Working Agreement dated November 19, 1971. When this occurs, release determination is the responsibility of the Corps (District Engineer).

Following the end of irrigation season at the end of August, releases to the East Bench Irrigation District were terminated. Despite reducing releases to record winter time low of 35 cfs, inflow was not sufficient to fill the conservation pool prior to the resumption of irrigation releases in May. This was the second consecutive year that the pool level had not risen to the top of the conservation pool.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 3,416 cfs Jun 22 84 2,561 cfs Jun 25 84 2nd 2,800 cfs Jun 20 75 1,289 cfs Jul 31 75 3rd 2,208 cfs Mar 31 69 1,275 cfs Aug 12-24 75

Pool-Date

Highest 5564.70 Jun 25 84 2nd 5556.88 Jul 22 75 3rd 5554.54 Jun 25 76

Minimums of Record (since initial fill):

Pool-Date

Lowest 5508.67 Aug 23-25 89 2nd 5516.80 Oct 11 74

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

130,970, 44% of normal 124,071, 41% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

418, 21 Mar 90 942, Jun 30

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

5531.88, May 6 5508.67, Aug 23 CLARK CANYON DAM AND RESERVOIR BEAVERHEAD RIVER BASIN, MONTANA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 5570

I I I I I I I I I I I I I I TOP OF FLO 00 c ONTROL ZONE (EL 5560.4)

5560 - - t l J t J. J .l J. l _l J l J TOP OF REP LACE MENT ZONE (EL 5556.5) ------

~ 5550 U') . ------TO P OF JOINT USE ZONE (EL 5546.1) fltvA ~-- !1------, ~--r-1--r-l--l--r-l ______~ / V\ \,. } ti 5540 ~~v ~I ~I TOP OF CONSERVATION w NE (EL 5535.7) L.a.. v zo .. ---V------~l ------z -IP--- 0 5530 I v r\ 1-- / [\ <{ v v > v w v / \ d 5520 I \ l/ 1\ v 5510 v '-v

5500 80 81 82 83 84 85 86 87 88 88 A S 0 N 0 J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I

" . GLENDO DAM AND RESERVOIR NOR'l :i PLATTE RIVER BASIN, WYOMING 1989-1990 REGULATION

Glendo Reservoir is regulated by the Bureau of Reclamation (Regional Director) except when the pool level rises into the exclusive flood control zone. When this occurs release determination is the responsibility of the Corps (District Engineer) as per the Field Working Agreement dated May 12, 1977. The bureau imposed an elevation restriction of 4650 ft. MSL in December of 1983 due to increased dike seepage. This restriction reduces the available flood storage space to 80 percent of the previous storage and precludes the use of the spillway and surcharge storage zone. on April 17, 1989, construction began to stabilize the downstream toe of the dikes. The final inspection was conducted on October 17, 1989. On February 16, 1990, the Bureau of Reclamation's Regional Office in Billings, Montana, officially rescinded glands Reservoir's operating restriction. The top of flood control pool is again at elevation 4653.

Glendo began the report period at elevation 4599.19 ft MSL (4. 86 feet lower than the beginning of the last report period). For the report period, inflows were 33 percent of average. No flood control was achieved during the report period.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 18,840 cfs May 15 65 10,292 cfs Jun 30 84 2nd 171560 cfs Jun 13 70 10,266 cfs Jul 01 84 3rd 14,661 cfs May 21 73 10,060 cfs Aug 26 83

Pool-Date

Highest 4650.90 May 27 73 2nd 4650.27 Jun 14 83 3rd 4648.45 May 31 71

Minimums of Record

Pool-Date

Lowest 4548.10 Sep 28 66 2nd 4560.42 Sep 26 72

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

742,421, 33% of normal 756,490, 63% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

4302, Aug 28 7610, Aug 1

Peak Pool Elevation (ft MSL) Minimum Pool Elevation (Ft MSL)

4627.45, Jun 11 4569.96, Sep 6 GLENDO DAM AND RESERVOIR NORTH PLATTE RIVER BASIN, WYOMING 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 4660 I I I 1 1 TOP OF FLOOD I cbN+R6L z6NEI (~L 46~3~ I ------] l_T_T_f_T_r-rT-r------4650 POOL RE STRICTION (EL 4650)

4640 ------t ------1_-- )-- OP 0 F-CONSERVATION- 4630 1 "-- f1 zo NE (EL 4635) ~ ( . ' I N r II ::::E I~ f ..... 4620 AI ! LLJ LLJ I "' / 1\ LL... 4610 z 0 v \ i= 4600 / <( > ~ 4590 ,/ LLJ 4580 1/

4570 I

4560 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I HEART BUTTE DAM AND RESERVOIR (LAKE TSCHIDA) HEART RIVER BASIN, NORTH DAKOTA 1989-1990 REGULATION

Heart Butte Reservoir is regulated by the Bureau of Reclamation (Regional Director) except when the pool level rises into the exclusive flood control zone. When this occurs, release determination is the responsibility of the Corps (District Engineer) as per the Field Working Agreement dated March 15, 1951.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 22,450 cfs May 09 70 4,050 cfs Apr 09 52 2nd 22,000 cfs Apr 17 50 3,931 cfs May 31 78 3rd 12,960 cfs Apr 06 52 3,864 cfs May 13 70

Pool-Date

Highest 2086.23 Apr 09 52 2nd 2083.77 Mar 31 78 3rd 2082.70 May 12 70

Minimums of Record (since initial fill):

Pool-Date

Lowest 2052.80 Dec 31 61 2nd 2054.70 Apr 01 62

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

15220, 16% of normal 15685, 17% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

500, May 25, Jul 2 127, Jul 17

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

2057.95, Aug 1 2054.44, Jul 31 HEART BUTTE DAM AND RESERVOIR (LAKE TSCHIDA) HEART RIVER BASIN, NORTH DAKOTA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the . ' current reporting period expanded for ease of reading. 'j 2095 ------t-----t---- I r- -1-- t- -1-- i--r- +-t-+-i--t-+- TOP OF FL 000 CONTROL ZONE (EL 2094.5)

2090

2085 _j. V! 2080 ~ 1- tj 2075 u.. .. 6 2070 I- <( TOP OF CONSERVATION JL I l.ll r-____ ?9~E _{E!:-_ ~-OEJ~.!? r-- ~ 2065 ------1~- - ~- If~ ------...J -t ~- w {\ 2060 l f\.l \ \ A y v 'v \., ~\ \.. 1\~ f--. r\ 2055 -

2050 80 81 82 83 84 85 86 87 88 89 ASONDJFMAMJJ 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I JAMES RIVER BASIN, NORTH DAKOTA 1989-1990 REGULATION

Jamestown Reservoir is regulated by the Bureau of Reclamation (Regional Director) except when the pool level rises into the exclusive flood control zone or that portion of joint use conservation-flood control zone required for flood control, as per the Field Working Agreement dated July 15, 1975. When this occurs, release determination is the responsibility of the Corps of Engineers (District Engineer).

The pool level remained below the top of the conservation zone for the entire report period and hit a record low (since initial fill) of 1425.58 ft above MSL. This is indicative of the continuing drought conditios experienced in this region.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 7,220 cfs Apr 18 69 489 cfs Apr 16 83 2nd 3,300 cfs Apr 04 87 400 cfs Mar, Apr, May 66 400 cfs May, Jun, Jul 69 3rd 2,900 cfs May 03 79 370 cfs Apr 15-19 87

Pool-Date

Highest 1444.10 Apr 27 69 2nd 1442.04 Apr 16 87 3rd 1440.90 Apr 01 73

Minimums of Record (since initial fill):

Pool-Date

Lowest 1427.25 Jul 31 89 2nd 1427.46 Sep 31 73

Maximum Combined Discharge (Pipestem and Jamestown)

Combined Pipestem Jamestown Date

Highest 489 cfs 0 489 cfs Apr 16 83 2nd 488 cfs 150 cfs 338 cfs Apr 28 75 3rd 475 cfs 125 cfs 350 cfs May 31-Jun 8 74 4th 470 cfs 100 cfs 370 cfs Apr 15-19 87

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

2564, 9% of normal 9, 0% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

74, Sep 24 3, Oct 17

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

1427.22, Sep 11 1425.58, Jul 31 JAMESTOWN DAM AND RESERVOIR JAMES RIVER BASIN, NORTH DAKOTA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 1455 ------J---- _I_--- _I_---- t I__ 1__ I__ J__ ! __I __ l __ L_ ------TOP OF FLOOD CONTR OL ZONE (EL 1454)

1450 . _J. ~ 1445 :::E 1- w w LL... 1440 z 0 1\ i= ~ TOP OF JOINT USE <( ZONE (EL 1432.7) Ci 1435 II _J w ------~ ------(\ \ (\ -kl/ ,_A f./""-A __ ,_ -\ 1430 \ ---- ~ ------'1-----'t.fll_,.,. ------~ ------

TOP OF CONSERVATION r-....- r--. :--.. ZONE (EL 1429.8) ~ ~ 1425 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS I REPORT PERIOD I

.. +·: .... ,., ...... ,~ ...... ,' " ' KEYHOLE DAM AND RESERVOIR BELLE FOURCHE RIVER BASIN, WYOMING 1989-1990 REGULATION

Keyhole Reservoir is regulated by the Bureau of Reclamation (Regional Director) except when the pool level rises into the exclusive flood control zone as per the Field Working Agreement dated February 11, 1970. When this occurs release determination is the responsibility of the Corps of Engineers (District Engineer).

The pool level hit a record low of 4070.73 feet above MSL on September 19, 1989. This was due to releases made in response to irrigation demands.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 10 '720 cfs May 19 78 1,347 cfs May 24 78 2nd 4,780 cfs Feb 29 72 820 cfs May 23-24 62 3rd 3,530 cfs Jun 18 62 801 cfs Mar 11-15 72

Pool-Date

Highest 4100.38 May 21 78 2nd 4098.78 Mar 07 72 3rd 4096.41 May 06 73

Minimums of Record:

Pool-Date

Lowest 4071.51 Dec 12-25 81 2nd 4074.08 Jul 31 89

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

18017, 55% of normal 18217, 113% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

683, Feb 26 177, Aug 1

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

4075.53, May 24 4070.73, Sep 19 KEYHOLE DAM AND RESERVOIR BELLE FOURCHE RIVER BASIN, WYOMING 1989-1990 REGULATION

A 1 0-year pool elevation hydro graph is shown below, with the current reporting period expanded for ease of reading. 4115 1 I I I I .1 I I I _I rbp 0~ FLO~D cONTR OL ZONE (EL 4111.5) ------4110

4105 . ~ 4100 ------. TOP OF CONSERV ATIO N ZONE (EL 4099.3) ~ 1- 4095 w w ~ u..... 4090 z 0 \ 1- 4085 ~ <( > ~ ("'- ~ 4080 J D !"\ 1\ w \_ ~ \r~ \_ 4075 ~ rv r J\ ~ ~... lr r--- l f l i\ 1\ 4070 -

4065 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS I REPORT PERIOD I

''·):·, ';:1 ·t ,{ :"';ii''', <'"·"''·\.,; ,.~ w ~\~ • ~. ; I ~- ·; PACTOLA DAM AND RESERVOIR RAPID CREEK BASIN, SOUTH DAKOTA 1989-1990 REGULATION

Pactola Reservoir is regulated by the Bureau (Regional Director) except when the pool level rises into the exclusive flood control zone. When this occurs, release determination is the responsibility of the Corps (District Engineer) as per the Field Working Agreement for this project dated August 27, 1969.

The pool began the report period at elevation 4539.70 ft. MSL, almost 40 feet below the base of the flood control zone. The pool remained in the conservation zone the entire period. From August 1 to September 30 the pool continued to decline until May through June when the pool levels started to rise and then decline in July. The pool remained fairly level from September through February with a minimum release of 15 cfs made in order to maintain downstream fisheries. Beginning in April storage was again drafted in response to irrigation demands.

A new lowest pool of record was set. No flood control was achieved during the period.

Maximums of Record: Daily Inflow-Date Daily Outflow-Date

Highest 1,110 cfs l1ay 16 65 500 cfs May 20 65 2nd 485 cfs May 11 78 350 cfs May 22 78 3rd 445 cfs Jun 10 72 255 cfs May 11 83

Pool-Date

Highest 4585.87 May 19 65 2nd 4585.44 May 21 78 3rd 4585.06 Jan 22 72

Minimums of Record (since initial fill):

Pool-Date

Lowest 4533.12 Feb 21 90 2nd 4539.94 Jul 31 89

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

18370, 60% of normal 4030, 62% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

95, Apr 25 110, Jul 3

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

4543.65, Jun 18 4533.12, Feb 21 PACTOLA DAM AND RESERVOIR RAPID CREEK BASIN, SOUTH DAKOTA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 4630 I I I I I I I I I I I I TOP OF FLOOD CONTRO L ZO NE (EL 4621.5) ------4620

4610 . ~. 4600 :::::?! 1- 4590 w w TOP OF CONSE RVATION ZONE (EL 4580.2) l.L. 4580 - - __ fl. - ... - _/:'\._ ------.. v fftV z vl 0 ~~ 1 ~ .LL 1- 4570 v r <{ J > \ v ~ 4560 u w l }\ 4550

V"' 4540 / \._ ~ ..-" 4530 ""' 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS REPORT PERIOD

• . ' ,. _.~.. •f.:' ' ' • SHADEHILL DAM AND RESERVOIR GRAND RIVER BASIN, SOUTH DAKOTA 1989-1990 REGULATION

Shadehill Reservoir is regulated by the Bureau of Reclamation (Regional Director) except when the pool level rises into the exclusive flood control zone as per the Field Working Agreement dated May 15, 1972. When this occurs, release determination is the responsibility of the Corps of Engineers (District Engineer).

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 32,152 cfs Apr 08 52 5,078 cfs Apr 10 52 2nd 9,900 cfs Mar 29 78 4,190 cfs Apr 01 78 3rd 6,730 cfs Mar 13 72 3,020 cfs Mar 16 72

Pool-Date

Highest 2297.90 Apr 10 52 2nd 2282.42 Apr 01 78 3rd 2276.37 Mar 15 82

Minimums of Record (since initial fill):

Pool-Date

Lowest 2258.62 Nov 17 81 2nd 2259.11 Feb 28 62

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

34,643, 47% of normal 20,428, 34% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

525, Feb 28 40, Jul 4

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

2269.49, May 7 2266.10, 4 Dec SHADEHILL DAM AND RESERVOIR GRAND RIVER BASIN, SOUTH DAKOTA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading.

2305 I I I I I I I I I I I I TOP OF FLOOD CONT ------R_q~_ Z~t-:!~ {~!:--~-~Q?)__ ------2300

2295 . ~. 2290 ~ 1- 2285 1-- w w l.&... 2280 z - 0 1- 2275 1--t- TOP OF CONSERVATION ·- ~ ____ -~Qr_-Jf.:_ _(_E_~ _~??_U~j______> ------1\-- -1\-- f\-- ~- -1\------~ 2270 A- w V'~ \. \ v ['.. \ ['... -- ~ u~ 1'-- _/ 2265 ~ _[\. \ J 2260 1\ -"\ "\,

2255 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 CALENDAR YEARS REPORT PERIOD

''i •,, • '!". ;, . :A,_,.., . '', ~·~ •._ TIBER DAM AND RESERVOIR (LAKE ELWELL) MARIAS RIVER BASIN, MONTANA 1989-1990 REGULATION

The Bureau of Reclamation and the Corps signed a new Water Control Agreement and Flood Control Storage Reservation Diagram for Lake Elwell and Tiber Dam, on March 14, 1983. The previous agreement, made October 30, 1964, was void on March 29, 1966 when the Bureau gave notice that structural problems with the spillway and its foundation required that the spillway gates remain fully open until repairs could be made. Repairs, completed in October 1981, consisted of replacing the upstream section of the spillway and raising the dam 5 feet.

The Reservoir is regulated by the Bureau except when the pool level rises into the flood control zone or that portion of the joint use (conservation-flood control) zone required for flood control as per the water control agreement. When this occurs, release determination is the responsibility of the Corps (District Engineer). When replacement storage is required for the downstream Fort Peck Reservoir, releases from Tiber Dam will be adjusted beginning March 1, based on anticipated inflow, to fill the reservoir to elevation 3008.1 ft. MSL prior to mid July. Minimum releases to achieve this fill are 300 cfs.

Winter inflows were at record levels. November's was the highest since the project was completed in 1957. November's inflow was 424% of average, December's was 265% of average and January's was 225% of average. Despite record maximum discharges in December, January, and February, the March 1 pool elevation was 2981, 5 feet higher than the target pool of 2976. The maximum pool of 2992.5 on July 5 was the fourth highest of record.

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 102,888 cfs Jun 10 64 10,300 cfs Jun 13-14 64 2nd 53,053 cfs Jun 21 75 5,777 cfs Jun 25 75, Jul 11 75 3rd 25,200 cfs Feb 26 86 5,308 cfs Jun 22-24 67

Pool-Date

Highest 3005.59 Jul 12 65 2nd 3001.91 Jun 13 64 3rd 2993.94 Jun 29 75

Minimums of Record (since initial fill in August 1956):

Pool-Date

Lowest 2953.81 Mar 28 68 2nd 2955.31 Apr 27 67 TIBER DAM AND RESERVOIR (LAKE ELWELL) MARIAS RIVER BASIN, MONTANA 1989-1990 REGULATION

A 1 0-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 3015 ------_____ L____ l ____ ! ____ I ill_ _l _ _L l_L 1_ J_ ~ l ____ -. TOP OF FLOOD CON TROL ZONE (EL 3012.5) 3010 ______l ____ L____ l ____ j __ j __ ----- I L_J __ L_J __ i __ l_J __ l ____ -. TOP OF REPLACEMENT/LOCAL FL 000 CONTROL ZONE (EL 3008.1) 3005

• 3000 _J. ~ 2995 ~ ------·------TOP OF JOI NT USE ZONE (EL 2993) A 1\ ti 2990 IL w 1\ u_ 2985 ~ fl\ ~ ~ 1---- h. I .. ) v \... kf ~ z ~ \ {\ 0 2980 ~ A \ ""-1--lJ 1- \ 4: __ (\_ w~ IY____ )------' ------· > 2975 'J--- ~\d-\ w ~N _J TOP OF CONSERV ATIO N w 2970 ZONE (EL 297 6)

2965 \ 1\,rj \~i 2960 ~.1

2955 80 81 82 83 84 85 86 87 88 89 A S 0 N 0 J F M A M J J 1989 1990 [ CALENDAR YEA}§] I REPORT PERIOD I

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

829,615, 124% of normal 724,812, 119% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

5064 May 31 1794, Aug 1

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

2992.51, Jul 5 2980.58, Apr 1 YELLOWTAIL DAM AND LAKE (BIG HORN LAKE) BIG HORN RIVER BASIN, MONTANA 1989-1990 REGULATION

Yellowtail Reservoir is regulated by the Bureau of Reclamation (Regional Director) except when the pool level rises into the exclusive flood control zone (3640 ft. MSL) or that portion of the joint use zone required for flood control as per Field Working Agreement dated March 5, 1971. When this occurs, release determination is the responsibility of the Corps of Engineers (District Engineer).

Maximums of Record:

Daily Inflow-Date Daily Outflow-Date

Highest 29' 775 cfs Ju1 01 67 24' 721 cfs Ju1 08 67 2nd 19,005 cfs Jun 10 81 14,947 cfs Jul 03 70 3rd 18,607 cfs Jun 26 69 12,462 cfs Jun 10 68

Pool-Date

Highest 3656.36 Jul 06 67 2nd 3648.55 Jul 13 78 3rd 3646.99 Jul 16 83

Minimums of Record (since initial fill):

Pool-Date

Lowest 3583.30 Apr 14 89 2nd 3584.45 Mar 11 70

Report Period: (August 1, 1989 through July 31, 1990)

Total Inflow (AF) Total Outflow (AF)

1,962,460, 77% of normal 1,788,170, 72% of normal

Peak Daily Inflow (CFS) Peak Daily Outflow (CFS)

7117, Jun 12 3703, Nov 23

Peak Pool Elevation (Ft. MSL) Minimum Pool Elevation (Ft. MSL)

3635.45, Jul 31 3593.39, Apr 13 YELLOWTAIL DAM AND LAKE (BIG HORN LAKE) BIG HORN RIVER BASIN, MONTANA 1989-1990 REGULATION

A 10-year pool elevation hydrograph is shown below, with the current reporting period expanded for ease of reading. 3660 ------!---- _L____ l ____ J L_ J _l_ J _J __ l_ J _J_ J _ ------(TOP OF FLOOD CON TROL ZONE EL 3657) 3650 ~ TOP OF JOINT USE ZONE (EL 3640) • 3640 ...J. ~ (~ (/). ~ ~ ~ (\ ~ 3630 ~ .I 1- L.a.J L.aJ "' ~h./ 1/ \ L.a... 3620 .. 1\ j Il z I -.../ 0 ------~- -- -- ~ -f .\ w \~ ~ ~~~ ~ 3610 I L.aJ> ...J 1\ ( L.aJ 3600 1/ ~ \ v v 3590 ~ T OP OF COLERVATION zONE (EL 3614) ~ 3580 80 81 82 83 84 85 86 87 88 89 A S 0 N D J F M A M J J 1989 1990 I CALENDAR YEARS I I REPORT PERIOD I

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