BOWDOIN NATIONAL WILDLIFE REFUGE

and WETLAND MANAGEMENT DISTRICT

ANNUAL WATER MANAGEMENT PLAN 1999 WATER USE REPORTS 2000 RECOMMENDATIONS

Black Coulee NWR/WP A Crcedman Coulee NWR Hewitt Lake NWR/WP A Thibadeau NWR

Beaver Creek WP A Dyrdahl WPA Holm WPA Ko rs beck WP A

McNeil Slough WPA Pearce WPA WebbWPA

Submitted: Date: Refuge Manager

Approved: Date: GARD, Northern Ecosystems

Concur: Date: Refuges Supervisor

Reviewed: Date: Chief, Div. Of Water Resources

ANNUAL WATER MANAGEMENT PLAN

1999-2000

BOWDOIN NATIONAL WILDLIFE REFUGE Malta, Montana

and

BOWDOIN WETLAND MANAGEMENT DISTRICT Phillips, Valley, Blaine and Hill Counties, MT

by

Fritz Prellwitz March 2000

ANNUAL WATER MANAGEMENT PLAN

INTRODUCTION

Water management during 1999 was similar to that of 1998 with an inability to purchase adequate water to fill Refuge wetlands (Figure 1) after a spring with minimal runoff. A moderate botulism outbreak killed 303 birds on Lake Bowdoin, probably due in. part to a lack of adequate water. With no more Drought Relief Funds and insufficient base funding, water could not be purchased in sufficient quantity to reduce the risk of a disease outbreak. Lake Bowdoin entered the winter of 1999-2000 with a water level 1.44 feet lower than the fall high in 1996. Migratory Bird money ($3,500) was again used to purchase water for the Lakeside and Lakeside Extension Units for duck banding purposes. Water was delivered to Lake Bowdoin during 09-27 August and to the Lakeside Unit during 21 July to 16 August. No water was delivered to Goose Islands Pond and the Drumbo Unit in 1999. With reduced funding for water delivery costs, these units received water only from summer flows of irrigation return water and runoff from precipitation falling on irrigation- saturated soils. Both units were significantly lower in fall of 1999 than in fall of 1998.

The U.S. Geological Survey (USGS - Helena) completed a final report for their Water/Salt Balance Computer Model for Refuge water units at Bowdoin in March, after nearly ten years of data gathering and model calibration. The report tested several water management scenarios (Figure 2) with regard to possibly lowering salt load in Lake Bowdoin and Dry Lake. The computer model, however, would allow input only of an average annual irrigation return flow amount, and USGS Hydrologist Eloise Kendy recommended that actual amounts as determined by flow measurements be reported in Annual Water Use/Management Plans as documentation of our water use in support of our water rights. The final report was immediately put to use for assessing impacts of an irrigation water storage proposal from the Montana Reserved Water Rights Compact Commission.

Beaver Creek did not flood during spring of 1999, and spring runoff was minimal. A water transfer from Lake Bowdoin to Dry Lake under the ice was tried once again during late winter and early spring of 1998 - 1999. The intent was to transfer salt-concentrated water under the ice (pure water) into Dry Lake where salt might blow away after summer evaporation the following year. Considerable salt did blow away during periods of high wind during the afternoons of 07-08 October.

Two impoundments southeast of Lakeside Extension modified during summer of 1996 were named during 1999 via a contest among Refuge employees. Durbian was the winner with Boot and Leg Marshes, or Bootleg Marsh when discussed as one. Prellwitz completed basin area/capacity surveys for Boot and Leg Marshes during 12-13 July at the request of Cheryl Williss, Water Resources (WR) Chief. Data were sent to Ken Bottle in WR for computer map generation prior to any reserved water right determinations for Bowdoin Refuge. Initial maps indicated that a few more laser shots were needed. Prellwitz completed additional surveying on 27 October and notes for an additional 230 points were sent to Ken Bottle on 01 November. No water was pumped into Bootleg Marsh during 1999. Minimal spring runoff had entered these

impoundments and both were dry by mid summer, but the water level in Lakeside Extension was insufficient for pumping to Bootleg Marsh.

I. GENERAL

A. Water Rights

Water rights filings for Bowdoin NationaJ Wildlife Refuge (NWR) (Figure 1) have a complicated history, involving agreements and coordination with the Bureau of Reclamation (BR) during construction of the Milk River Project, a federally funded irrigation project for North central Montana (Table 1). Water rights claimed for Fresno Reservoir, an instream BR storage facility on the Milk River northwest of Havre, involve potentiaJ storage in the reservoir for later release through the Milk River to a diversion at Dodson where water can enter the Dodson South Canal and then be transported to Bowdoin NWR. The Dodson South Canal lies on the north edge of the Refuge, and was built primarily for transporting water to Nelson Reservoir, an offstream storage facility. The canal, when constructed, diverted several small drainages which had supplied runoff water to Lake Bowdoin.

Other water rights often are ineffective in supplying necessary water for wildlife habitat management at Bowdoin NWR. Beaver Creek water rights primarily are flood waters which can enter major water units at Bowdoin NWR during spring runoff or during other major weather events. Flood waters enter Bowdoin less than five times in ten years. Water from Beaver Creek is not available at other times because of senior water rights on private lands located downstream. Wind mills have not been used since livestock grazing was eliminated from the refuge in the 1970s. Bowdoin NWR has a complex system of dikes, canals and water control structures for use in moving water between water units, and for handling flood waters entering from Beaver Creek (Figure 2). The Montana Department of Natural Resources, Water Rights Bureau, is continuing to give adjudication priority to the Milk River System.

Negotiations for a reserved water right for Bowdoin Refuge came to the forefront in 1999 as the State Water Compact Commission began a series of hearings on settlement of the Milk River Basin, especially in regards to tribal water claims for the Fort Belknap Reservation. It was the opinion of Regional Office Chief of WR Cheryl Williss and solicitor John Chaffin that a Bowdoin settlement should be reached at the same time and be included in the Compact in order to receive Congressional funding for any designated water facilities and/or purchases. It was also an opportune time to reach some kind of discharge agreement in order to release high conductivity water into Beaver Creek outside of the irrigation season. A Compact settlement passed by both the State legislature and Congress would bring favorable politicaJ pressure on the State's Department of Environmental Quality to agree to some type of release plan. Luna, Prellwitz, Chaffin, Williss, and Jana Varner (WR) met at Bowdoin on 25 May to prepare for an upcoming Commission meeting in Helena on 23 July. They identified data gaps and began to prepare a draft proposal for water quantities needed for the various impoundments at Bowdoin Refuge.

Compact Commission Hydrologists and Engineers, however, caught us by surprise by offering an irrigation water storage alternative for Bowdoin to the negotiations. Their proposal was to store up Table 1. Water rights volumes and priority dates for Bowdoin NWR.

Priority Filing Source RateNolume Date Date Diffuse surface 1,600 AF 02/ 14/ 1936 12/09/1981 runoff and irrigation return

Fresno Reservoir 8,000 AF 09/09/1937 12/09/1981 (FWS filing)

Fresno Reservoir 3,500 AF (BR filing)

Beaver Creek 3,500 CFS/ 02/ 14/1936 12/09/1981 35,500 AF

Windmill Well #1 5 GPM/0.31 AF 05/11/1972 12/09/1981

Windmill Well #2 20 GPM/1.39 AF 05/17/1972 12/09/1981

Spring (pond, SE .09 GPM/1 .0 AF 02/ 14/1936 12/09/1981 comer by Dry Lake)

Headquarters Well #2 55 GPM 12/03/1979 40M-C-025539 Use: DOM POD: SENENW Sec. 5, T30NR3 l E

Headquarters Well 30GPM 02/28/1937 - Res. 1936 40M-W-189874 Use: DOM (fire protection) POD: SENENW Sec. 5, T30NR31 E

to 10,000 AF of irrigation water in Lake Bowdoin and/or other water units for release to Glasgow Irrigation District irrigators during late July and August, with refilling of Bowdoin during September and October. The additional water would come from the Milk River System, and from construction of a canal from Beaver Creek to Bowdoin to create a flow-through system whereby water from spring runoff and minor flood events would flush Bowdoin water units and lower conductivity levels to more acceptable levels in 7 to 10 years for discharge to Beaver Creek. It was up to us to identify biological concerns and constraints, and to assist with a project

reconnaissance survey in cooperation with the Commission, BR, and local landowners. We initiated contacts with aquatic plant and aquatic systems experts immediately.

Luna and Prellwitz attended the Reserved Water Rights Compact Commission meeting in Helena on 23 July. Prellwitz and Eloise Kendy (USGS) made presentations on Bowdoin Refuge and the salt/water balance model development. Prellwitz submitted additional data on spillway elevations to Kendy on 30 July for use in running additional model runs if Bowdoin were to be used for increased deliveries of irrigation water for storage and then discharge. Luna and Prellwitz met with Berg (CMR NWR) and Compact Commission staff Stan Jones and Bill Greiman during 25-26 August regarding the feasibility of the proposal to make Bowdoin a water storage facility for downstream irrigators. They looked at potential sites for directing water from Beaver Creek to Bowdoin.

Luna and Prellwitz attended a second Reserved Water Rights Compact Commission public meeting in Malta on 21 September. Water users were concerned about an environmental group's proposal to drain Sherburne Reservoir because of concerns over bull trout. One derogatory comment on piping plovers on Nelson Reservoir was also aired. The proposal to route Beaver Creek water through Bowdoin Refuge and also store irrigation water in Bowdoin brought very little comment. Stan Jones, Hydrologist for the Commission, then toured Bowdoin and the Beaver Creek area with Prellwitz on 22 September in anticipation of future reconnaissance survey work. Jones, Steve Henry (CMR NWR) and Prellwitz began those surveys on 30 September, completing them on 08 October. Joe Rohde, a Hydrologic Engineer for BR, toured the proposed Beaver Creek diversion routes with Jones and Prellwitz on 12-13 October prior to developing a cost estimate for proposed facilities .

Luna and Prellwitz invited Dr. Ned "Chip" Euliss from Northern Prairie Science Center to Bowdoin on 23 November to tour the Refuge and make recommendations regarding the significance of impacts from the Compact Commission's irrigation water storage proposal. We also received comments from Don Reed, a Wisconsin botanist who has worked on a plant list for Bowdoin since 1987.

B. Purpose and Methods

Water is paramount to wildlife management at Bowdoin NWR. Water diverted to Bowdoin NWR is used to maintain and manage ponds, lakes, and marshes ranging in size from one acre to more than 5,459 acres. These wetlands provide habitat for waterfowl, water birds and other wetland wildlife. Water management is primarily intended to provide production and migration habitat for waterfowl and other migratory birds indigenous to the area (a primary Refuge objective at Bowdoin) and to manage for the threatened piping plover.

Precipitation, irrigation return flows, Beaver Creek flood water, and Milk River Project water are the primary sources of water for Bowdoin NWR. Most water movement on Bowdoin Refuge is by gravity flow. The first two sources normally contribute nearly I 0,000 acre-feet (AF) per year. Beaver Creek floods infrequently and the magnitude of flooding is variable. Milk River Project

water, delivered by the Malta Irrigation District, is the most significant and dependable source of water for the Refuge. The long term yearly average of delivered Milk River Project water is about 5,500 AF, with a high of 9,340 AF in 1990. Water intake structures divert Project water directly into Lake Bowdoin, Goose Islands Pond, Headquarters Pond, and the Lakeside Unit. Drurnbo, Dry Lake Pond, Dry Lake, Farm Ponds, and Teal Ponds receive water secondarily from water flowing through the previous water units and then discharged through a system of dikes and canals. Strater Pond, Black Coulee Pond, and Patrol Road Pond, receive water from natural runoff, groundwater recharge and irrigation return flow. Amounts of water received annually are quite variable (Table 2), and difficult to measure. Black Coulee is a significant source of natural runoff, but it is not possible to differentiate runoff from irrigation return flows entering the Refuge through Black Coulee.

It has been the objective of past water management at Bowdoin to maintain operational water levels in all Refuge wetlands. This management philosophy has not provided for periodic flushing, except during infrequent flooding by Beaver Creek, due to an inadequate water supply. The long term effect has been elevated saline conditions in Lake Bowdoin Dry Lake, and Drumbo, as measured by conductivity. Conductivity levels in Lake Bowdoin and Dry Lake are above legal discharge limits set by the State of Montana Department of Environmental Quality.

Present management emphasizes maintaining freshwater conditions in smaller units such as Lakeside, Teal Ponds and Farm Ponds, while attempting to reduce salinity in Lake Bowdoin, Dry Lake Pond, Dry Lake, and Drurnbo when adequate water is available. Construction of new water facilities during the 1980s has significantly improved water management capabilities at Bowdoin Refuge. New facilities include a dike between Drumbo and Lake Bowdoin, a water control structure in the Southeast Bay dike of Lake Bowdoin, a dike separating Dry Lake Pond from the remainder of Dry Lake, and spillways ("Texas Crossings") in the Lake Bowdoin and Dry Lake dikes.

C. Problems

Water quality is a problem at Bowdoin which has received increased emphasis in recent years. A long range goal is to reduce salinity and restore freshwater conditions in Refuge wetlands. This will not be possible in the larger water units until an adequate supply of supplemental water becomes available for use at Bowdoin, and then only if discharged Refuge water can meet State of Montana water quality standards for releases into the State's waterways. Present water management facilities, however, do permit efficient use of available water. The Water/Salt Balance Computer Model has tested several hypothetical water delivery/discharge scenarios and determined that improvements in water quality can be made through innovative water management.

Water quality has been monitored for a number of years at Bowdoin NWR. Monitoring started with a few study sites in 1976. The program was expanded and modified several times. The most recent addition was chemical analyses (pH, DO, hardness, dissolved solids, and alkalinity) in 1988. Previously, only conductivity data were collected at each sample site. Surface water

sites, as well as temporary well sites, are now monitored from April through November when water might be entering Bowdoin and water quality could be changing. Table 2. Water sources, normal annual volumes (AF), and volumes

received (AF), Bowdoin NWR, 1994-1999.

Normal 1994 1995 1996 1997 Source Annual Volume VQlume VQlume VQlume VQlume

I Irrigation I

3,500

I 1,500 2,752 2,869 4,993

return* Runoff# 5,000-30,000 4,260 5,246 6,400 7,209 Milk River 3,500-6,000 8,076 6,290 8,849 3,683 Project Total 10,450-37,950 13,836 14,288 18,118 15,885

I°998 1999 VQlume VQlume

5 164 3,791

6,726 6,025 2,390 3,538

14,280 13,354

* Estimated for 1993 through 1994. The 1995 amount was calculated from comparisons to flow meter measurements in 1997 - 1998. The 1995 - 1999 amounts also include measured leakage from the Dodson South Canal. # Includes precipitation and Beaver Creek flood water. Estimated for 1994. Flood waters measured in 1996.

Conductivity (mmhos/cm3 or microsiemen per centimeter) readings from Lake Bowdoin during summer of 1999 (Table 3), for example, demonstrate the impact of evaporation in early summer, and water deliveries in mid summer, on water quality. Lake Bowdoin receives water along the west shoreline from the Malta Irrigation District via the Dodson South Canal. Delivery of fresh water during 09-27 August 1999 had an immediate effect on conductivity readings on the west side of Lake Bowdoin, but the east shore was not affected due to a lack of mixing. Conductivity readings increased significantly near the east shore of Lake Bowdoin by late October, but readings were relative to the amount of water in the lake. A higher water level dilutes the salts while a lower water level concentrates salts. Higher conductivity readings in fall of 1992 and 1993 were an indication of lower water levels, while the decrease in conductivity readings in 1994 - 1996 were a product of more water in the lake. The conductivity reading on the east shore was higher again in 1997 - 1999 because of there being less water Lake Bowdoin than in 1996 (Table 4). It is difficult to determine if salt levels are stabilizing unless one can compare conductivity levels at the same time and at the same water level each year.

Table 3. Conductivity readings from west and east shorelines of Lake Bowdoin, 1992 - 1999.

Date West East 12-13 May 6,830 8,110 18-19 August 580 9,010 02 November 7,200 9,060

I

West East Year Conductivitv

Fall 1992 7,410 10,2 10 Fall 1993 7,150 9,190 Fall 1994 6,020 8,040 Fall 1995 6,600 8,240 Fall 1996 5,410 7,350 Fall 1997 3,250 8,110 Fall 1998 5,350 9,450 Fall 1999 7,200 9,060

II. IMPOUNDMENT DATA

The larger water units on Bowdoin Refuge first had topographic basin maps drafted in 1981 , but there has not been a reliable method of measuring water levels on these units throughout the summer in order to document water use. Regional Surveyors in 1986 and 1987 established mean sea level (MSL) elevations for water control structures on Lake Bowdoin, Dry Lake, Drumbo, and Lakeside. It was planned to attach staff gauges to each of these structures and gather water elevation data relative to MSL, but the drought of the 1980s left the water level on some of these units below the intended staff gauge locations. The survey contract in 1994 updated elevation benchmarks on all water control structures, for both the bottom and top elevations of each structure, and the spillway elevations (Table 5).

Staff gauges were installed in alternate sites in deep water areas of the seven largest water units during the fall of 1990. Each gauge was attached to PVC pipe which had a threaded coupling on the bottom end. The coupling was then turned onto a threaded steel pipe driven into bottom sediments in deep water. The gauges can be removed each fall and thereby avoid ice damage. Only the PVC portions are removed. The steel bases remain in the water below the ice and are ready for Table 4. Bowdoin NWR water level elevations (feet), 1999.

Date Lake Bowdoin Drumbo Dry Lake Dry Lake Fann Pond Lakeside Lakeside Ext. Pond

03 Mar 2213.40 16 Mar 2211.60 2213.2 1 2220.51 2228.86 30 Mar 2211.57

Goose Island Pond 2215.45 2215.54

07 Aor 2211.61 2212.99 2211.2 1 13 Apr 22 12.57 2220.41 2229.24 2228.20 30 Apr 221 1.60 07 May 2211.53 22 12.73 2210.82 2212.43 2220.32 2229.16 2228.20 02 Jun 2212.82 18 Jun 22 11.62 2212.79 2211.25 2212.37 2220.3 1 2229.17 2228.32 06 Jul 2211.44 19 Jul 22 11.26 2212.54 2219.96 2228.66 2227.6 1 29 Jul 2211.10 22 12.47 2210.92 22 12.10 22 19.69 2229.53 2227.26 18 Aug 2212.20 22 12.76 2220.84 2229:45 24 Aug 2212.09 2212.62 2229.34 2226.57 27 Aug 22 11.55 30 Aug 2212.57

14 Sep 2211.42 15 Seo 2220.30 2229.01 2226.14 22 Sep 2211.36 2211.95 2210.80 22 12.44 13 Oct 2211.24 2220.15 2228.69 2225.9 1 19 Oct 2211.23 2211.94 22 10.68 22 12.30 IONov 2211.16 16 Nov 22 11.1 7 2228.36 2226.07

FALL 99 2211.17 2211.94 2210.68 22 12.30 2220.15 2228.36 2226.07 2214.33 FALL 98 2210.85 2212.91 low 22 12.60 2220.36 2228.86 2228.87 2214.67 FALL 97 22 11.79 22 12.89 2211.32 2216.61 2220.35 2228.83 2228.83 22 16.24 FALL 96 22 12.6 1 22 12.80 2211.24 22 12.27 2220.44 2227.48 2225.20 2215.98 FALL 95 22 11.60 2211.05 2212.07 22 19.64 2228.72 2228.71 22 15.92 FALL 94 22 10.9 1 22 11.27 22 12.12 22 19.05 2228.8 1 2228.80 2215.83 FALL 93 22 10.79 221 1.56 2212.08 2220.22 2228.39 2228.23 22 14.63 FALL 92 2210.69 2211.61 22 12.10 2220.44 2228.48 2225.84 22 15.5 1 FALL91 2211.25 2211.73 2212.30 2220.53 2228.86 2228.82 2215.76 FALL 90 2211.07 22 12.14 22 11.74 22 19.88 2228.28 2226.91 22 15.56

Table 5. Maximum impoundment areas and volumes, Bowdoin NWR, adjusted for 1994 spillway survey data.

Surface Area Volume Impoundment Elevation (acres) (acre feet)

Black Coulee Pond 2,224.72 8 16 Lake Bowdoin 2,213.41 5,459 20,649 Drumbo 2,213.95 207 679 Dry Lake 2,212.99 1,019 3,259 Dry Lake Pond 2,213.91 83 123 Farm Pond 2,220.68 15 37 Lower Farm Pond 2,217.42 5 7 Goose Island Pond 2,217.07 43 178 Lakeside 2,229.94 296 823 Lakeside Extension 2,229.94 46 290 Patrol Road Pond 2,217.18 3 7

2215.79

22 15.77 22 15.92 2215.88

2215.35

2214.33

Strater Pond 2 219.64 17 45 Headquarters Pond 4 17 Teal Pond No. 1 2,218.15 6 11 Teal Pond No. 2 2 218.15 1 Teal Pond No. 3 2,218.54 3 10 Teal Pond No. 4 2,220.46 4 16 Teal Pond No. 5 2217.47 3 3 Teal Pond No. 6 2,220.27 4 7

Total 7,226 26,178

reinstallation of gauges the following spring. The bases were driven deep into bottom sediments and cannot change in elevation. The PVC pipes are removed prior to freeze-up in fall and are replaced after ice-out in spring with no problems.

III. SUMMARY OF 1999 WATER USE

Total precipitation for 1999 at Bowdoin Refuge was 13.34 inches (1.112 feet) compared to 15.76 inches in 1998, and to a long-term average of 12.63 inches (1909-1999). Most precipitation fell during May (3.34 inches) and June (2.73 inches). Autumn was very dry with almost no snow at the end of the year. Conditions were not good for runoff from snowmelt in spring of 2000.

Headquarters Display Pond was mostly open on 15 March. Lakeside, Lakeside Extension, Farm Ponds and most smaller water units were ice-free or mostly ice-free on 26 March. Lake Bowdoin began to break-up on 01 April, and was mostly open on 07 April. The last remnants of ice remained near the north shore on 08 April, and both Lake Bowdoin and Dry Lake were ice-free on 09 April. Smaller water units froze on 03 November, but then broke up again during mild fall weather. Most began to freeze a second time on 19 November with all but Lake Bowdoin and Drumbo froze on 23 November. Lake Bowdoin was 90% frozen on 02 December with waterfowl keeping pools open on Lake Bowdoin and Drurnbo until 10 December. One small pool kept open by concentrations of waterfowl on Lake Bowdoin persisted until the Christmas Bird Count on 18 December.

Bowdoin NWR water units received less water in 1999 than in 1998 even though more water was purchased from the Malta Irrigation District (Table 2). Measurement techniques for irrigation return flows, canal leakage, spring runoff and discharges to Beaver Creek continued to improve in 1999, with more measurements taken. A total annual volume of 13,354 acre-feet (AF) received included 3,791 AF of return flows and canal leakage, 6,025 AF of runoff and precipitation, and 3,538 AF delivered by the Malta Irrigation District. Cost of delivered water was $13,267.50 ($3 .75/AF), and was paid for with Migratory Bird Money ($3,500) and base

funds ($9,767.50). Fall water levels generally were adequate, except for Lake Bowdoin which was 1.44 feet lower than in fall of 1996, and Drumbo and Goose Islands Pond which were very low.

Estimates of water storage from precipitation were made by measuring late June water elevations (Table 4) and then looking up surface areas for those elevations on capacity tables for each water unit. The amounts of water falling on those water surface areas were then calculated using the total annual precipitation measured at the Bowdoin Weather Station. The late June elevation was chosen because most of the annual precipitation is received by June or July and the impoundment elevations during that period best estimate the water surface area receiving precipitation directly from significant rainfall events. The water elevation of Lake Bowdoin in late June, for example, was approximately 2,211.62 feet MSL (Table 4). The capacity table for Lake Bowdoin lists a surface area of 4,127 acres at that elevation. Multiplying that surface area times 1.112 feet (13.34 inches of precipitation) yields a water input of 4,589.2 AF. The same calculation for each water unit resulted in a total precipitation volume of 6,024.6 AF for 5,412 surface acres in all units in late June. There was very little addition to this from spring snowmelt in 1999. Any runoff from the north side of the Refuge into Lake Bowdoin and Lakeside was included with canal leakage estimates because the two were inseparable during the Spring months.

Lake Bowdoin also received inflows from irrigation return flows and canal leakage, and from Irrigation District deliveries (Table 6). Net District delivery was 2,162.50 AF. Direct measured delivery to Lake Bowdoin included 2,560.83 AF during 09-27 August. Lake Bowdoin also received District water indirectly from the Lakeside Unit which was passed through Farm Ponds (182 AF) and Teal Ponds (73 AF) during August. Water was released from Lake Bowdoin to Dry Lake during March (410.64 AF), April (233.49 AF), and December (9.20 AF). Conductivity of the water on 07 April had dropped to 7,600 so flow was stopped. Flow was stopped in early April because melting of ice in March had diluting salts in Lake Bowdoin and outflow to Dry Lake was no longer salt- concentrated water. Table 6. Water use at Bowdoin NWR during 1999.

Impoundment

Black Coulee Pond Drumbo Drv Lake Dry Lake Pond Farm Ponds Goose Islands Pond Headquarters Pond-Lake Bowdoin

June surface area

(Acres)

8 157 732

40 13 36

4 4,127

Annual Irrigation precipitation" deliveries

AcrP-feet) (Acre-feet) 8.9 0

174.6 0 814.0 980.33 44.5 27 14.5 21 40.0 0 11.0- 19.84

4,589.2 2,162.50

Irrigation return flow* (Acre-feet)

0 10 0 0 0

19 0

2,798.79

I Lakeside 220 244.6 Lakeside Extension 35 38.9 Patrol Road Pond 3 3.3 Strater Pond 17 l 8.9 Teal Ponds 6 onds 20 22.2 Total 5,412 6,024.6

* Also includes leakage from the Dodson South Canal. " Includes spring runoff. - Includes 7 AF pumped from the Headquarters water well.

205.33 933.83 78 0

0 7 0 22

44 0 3,538.00 3,790.62

Irrigation return flows and canal leakage to Lake Bowdoin were recorded by flow meter measurements during 1999. Measured flows included 949.85 AF of return flows from Black Coulee through Black Coulee Pond and ground water surfacing in Strater Pond during all twelve months, 507.26 AF of return flows through Patrol Road Pond during March through early September, 110.56 AF of leakage from an old release structure in the Dodson South Canal which flowed into Lake Bowdoin near Long Island during February through May, 35 AF of combination runoff and canal leakage along the north side of Lake Bowdoin during February and March, 5 AF of return flows and runoff near the railroad tracks during April and May, 965.93 AF of runoff and return flows entering Drumbo and then passing into Lake Bowdoin during March through July, and 225.19 AF of canal leakage through the Bowdoin intake chute during February through May that was not measured by District Ditch Riders.

The amount reaching Lake Bowdoin from Black Coulee was in addition to 22 AF which remained in Strater Pond after the water control structure in this unit was repaired and the impoundment refilled with water in September. Black Coulee Pond was full all year with water spilling through the natural spillway.

Water levels in the Lakeside and Lakeside Extension Units were managed separately throughout 1999 after completion of a new water control structure in 1997 which separated the units. The Lakeside unit usually loses a foot of water during the winter months as water seeps under ground to Lake Bowdoin. This seepage probably also occurs during the warm months, but it is not easy to measure at that time due to evaporation and fluctuations in water level due to inflows and outflows. Annual precipitation added 283.5 AF to Lakeside and Extension, 14.5 AF to Farm Ponds, and 22.2 AF to Teal Ponds.

The bulk of the water entering Lakeside and Lakeside Extension was delivered water from the Malta Irrigation District, although not all of it was measured by Ditch Riders and billed to the Refuge. Paid delivery included 903 .33 AF during 21 July to 16 August. We also received 925.83 AF during February through July which was either Spring runoff passing through the District's open water release structure, or was leakage through the same structure during high flows to Nelson Reservoir in early summer. Lakeside also received 8 AF of runoff water from

north side drainages under the County Road during early March. Portions of these deliveries passed through Lakeside and were diverted to Teal Ponds during August (44 AF), to Lake Bowdoin through Teal Ponds in August (73 AF), to Farm Ponds during August (21 AF), to Lake Bowdoin through Farm Ponds in August (182 AF), to Dry Lake Pond during late July and August (27 AF), to Dry Lake through Dry Lake Pond during August (312 AF) and to Dry Lake through Teal Ponds during August (15 AF), for a net delivery of 205.33 AF (paid) and 933.83 AF (unpaid) remaining in Lakeside and 24 AF remaining in Lakeside Extension. The Lakeside Extension delivery from Lakeside was 19 AF in April and 5 AF in November. Lakeside Extension also received 54 AF of water pumped from the Dodson South Canal and passing through the Pearce WP A during October.

Precipitation provided 814 AF to Dry Lake and 44.5 AF to Dry Lake Pond. There are no irrigation return flow drains entering Dry Lake directly, so the remainder of water inflow in 1999 was received indirectly from Irrigation District deliveries and return flows through other units, or from flushing of smaller impoundments (Teal Ponds). Deliveries to Dry Lake through Lake Bowdoin included 653 .33 AF during March, April and December. Delivery through the Lakeside Unit included 27 AF to Dry Lake Pond during late July and August, 312 AF to Dry Lake through Dry Lake Pond during August, and 15 AF through Teal Ponds to Dry Lake during August, for a total of27 AF in Dry Lake Pond and 980.33 AF in Dry Lake.

Drurnbo and Goose Islands Pond received no Beaver Creek flood water during 1999. Irrigation return flow mixed with runoff flowed through the Drumbo Unit primarily along the railroad tracks, with 965.93 AF being passed into Lake Bowdoin through the water control structure in the southwest bay. Precipitation added 174.6 AF to Drumbo and 40 AF to Goose Islands Pond. No irrigation water delivery was made to these units in 1999 because of a lack of funds, and it was thought that irrigation return flows in late spring normally flush these units adequately. Approximately 19 AF of return flows stayed in Goose Islands Pond in March and April, and I 0 AF passed through to Drumbo during May. Water was discharged from the Drumbo Unit to Beaver Creek (30.3 AF) during March.

Headquarters Display Pond was the only other unit to receive Irrigation District deliveries. Display Pond received 4 AF from precipitation, 4 AF from pumping from the Refuge well during 01 April to 03 May, 3 AF from pumping during 22 October to 09 November, and a delivery of 19. 84 AF during 15-25 June. Irrigation return flows do not enter Display Pond. The intake canal which carries water to Display Pond flows water only when we have ordered a delivery from the District. All of this water ultimately seeps to Lake Bowdoin, and Display Pond was very low when entering winter.

The remaining smaller water units received the bulk of their water from irrigation return flows and runoff. Runoff from summer rains were mixed with irrigation return flows, especially when summer rains occurred during irrigations when soils were already saturated. Precipitation provided 8.9 AF to Black Coulee Pond, 3.3 AF to Patrol Road Pond, and 18.9 AF to Strater Pond. Return flows filled Patrol Road Pond with 7 AF while passing 507.26 AF on to Lake Bowdoin. Return flows and runoff from Black Coulee filled Strater Pond with 22 AF, and passed on 949.85 AF to Lake Bowdoin. Black Coulee flowed water only during February,

March, July, August and early September which was unusual, but ground water surfaced in Strater Pond and flowed through to Lake Bowdoin in all 12 months. All flows were measured in 1999, after having been estimated prior to 1997.

The Headquarters Well next to Quarters No. 1 was not used during 1999 and has not been used since December 1994. All Refuge buildings were supplied domestic water from Headquarters Well #2. all year long, although drinking water was supplied by a bottled water company and has been supplied that way since September 1998. Prellwitz and Barbour designed and installed an above- ground two-inch water line to the Headquarters Display Pond in late March in order to supplement water deliveries outside of the irrigation season when water normally is delivered. The two-inch plastic pipe could supply about 0.12 AF (27.4 GPM) of water per day to the Pond from the Refuge well's 2-hp water pump, but at a considerable loss in water pressure to other Refuge facilities. A water well contractor inspected our water system in early May and determined that we were probably ready for a new pump. Prellwitz assisted with pump replacement on 28 May when it was discovered that corrosion had severely damaged the pump connections and we were within months of a total failure. A new 3-hp pump delivered 0.17 AF (37.9 GPM) per day to Display Pond with very little Joss of water pressure to other facilities. All flow measurements were made at the end of the 300 feet of 2-inch plastic water line. Flow rates at the pump outlet were probably considerably higher than 37.9 GPM. We pumped 4 AF from the Refuge well to Display Pond during 01 April to 03 May, and 3 AF from 22 October to 09 November.

Water Levels

Water level elevations (MSL) were determined either from staff gauges or from known benchmarks on water control structures for 1999 (Table 4). This was done for all units except the smaller ponds which normally are kept full throughout most of the year. Volumes of water can be calculated from the area/capacity tables developed by two 1994 survey contracts, although these numbers are somewhat relative. Maximum management levels differ somewhat from potential capacities during flood situations. Lake Bowdoin, for example, is rarely kept above 2211 MSL for long, but the lower emergency spillway is at the higher elevation of 2213 .41 , and flood levels in October 1986 were probably three feet above that. The water levels of Lake Bowdoin, Drurnbo, Lakeside Extension and Goose Islands Pond were lower than desired at the end of 1999, while water levels of the other units were adequate.

Water Discharges to Beaver Creek

Discharges to Beaver Creek were measured with a 2-inch flow meter during 1999. All discharging was necessary to prevent over- topping of the Drurnbo water control structure and possible failure . The Drumbo Unit discharged water briefly in early March (30.3 AF). Conductivity of the water was 3,100. No water was discharged from Lake Bowdoin or Dry Lake to Beaver Creek during 1999.

IV. 2000 PROPOSED WATER USE

Water in 2000 will be purchased primarily with base funding or with an end-of-year appropriation from the Regional Office, if water is available from the Malta Irrigation District. The year 2000, however, may be a water short year in the Milk River Basin. A moderate base funding decrease in 2000 balanced with salary savings from a vacant position is providing limited money for water delivery. We will try to add water to all water units in late summer (late August to early October) in preparation for fall migration, to reduce the risk of a botulism outbreak, and to prepare duck banding sites. We will be ready to react to any need to receive water earlier than late August if piping plover nests are threatened by rising water on Nelson Reservoir. Emphasis will be placed on filling Lake Bowdoin by late fall so that flushing with runoff or flood water is possible in spring of the year 2001. This would also allow for moving some water from Lake Bowdoin to Dry Lake under the ice during winter as has been tried with some success in recent years. The goal of transporting water between these units in winter is to move salty water from Lake Bowdoin at the time of the year when salts are most concentrated due to the formation of ice cover which is predominantly pure water.

Dry Lake will again act as a sump for Lake Bowdoin and Dry Lake Pond. Fresh water from Lakeside will be transported to Dry Lake Pond during summer, with excess water allowed to flush salts from Dry Lake Pond into Dry Lake. Evaporation will expose shorelines and major portions of the Dry Lake basin to wind erosion from mid summer to early fall, and salts will be blown away rather than illegally discharged into Beaver Creek at a later time.

Water deliveries will again be directed to Lakeside and Lakeside Extension in late summer and early fall to flood waterfowl banding sites and to provide migration habitat for diving ducks. Water levels will have receded during early summer to provide nesting habitat for piping plovers displaced from Nelson Reservoir and for moist soil plant growth. Migratory Bird money ($3,500) is available to assist with duck banding efforts, and that money may be used to deliver water to banding sites on the Lakeside Extension Unit. Additional water will be channeled through Lakeside and diverted to Farm Ponds and the Teal Pond Complex at the same time that water is being transported to Dry Lake Pond. These smaller units will be filled and allowed to flush for a few days to freshen the water. Excess water would flow into either Lake Bowdoin or Dry Lake.

Headquarters (Display) Pond will be drawn down early in 2000 prior to replacement of the water control structure. This unit provides waterfowl and waterbird habitat and also serves as a "hospital pond" for holding sick birds that have been treated with antitoxin during any possible botulism outbreaks, but the old control structure has experienced siltation and leakage in recent years. Delivered water ultimately seeps to Lake Bowdoin, with Display Pond often losing a foot or so in water elevation during winter. The existing structure is probably an historic structure and will be left in place while a new structure placed directly west of the old structure will be designed to allow for periodic drawdowns.

Irrigation return flows and spring runoff should be adequate to maintain water levels in Black Coulee Pond, Patrol Road Pond, and Strater Pond, and possibly in Drumbo early in the year.

Irrigation return flows should also provide sufficient water for Goose Islands Pond for most of the year, and delivery of Irrigation District water from the Bowdoin Canal may only be necessary in late summer. Flushing of these units may still be possible during spring runoff in 2000. This management technique has being tried recently because of the large amount of water that has flown through these units in recent years from irrigation return flows and from major summer storms. Conductivity readings for the Drurnbo Unit normally are low enough in early summer to allow flushing and legal discharging into Lake Bowdoin and to Beaver Creek. Discharging is most likely to occur in early summer when irrigation return flows are augmented by precipitation from intense summer storms.

ANNUAL WATER USE SHORT FORMS

for

BOWDOIN WETLAND MANAGEMENT DISTRICT and

SA TEL LITE REFUGES 1999

by

Fritz Prellwitz