Powder/Tongue River Basin Water Plan
Technical Memoranda

SUBJECT:	Appendix J Storage Operation and Description TIE HACK
PREPARED BY:	HKM Engineering Inc.
DATE:	March 2002

KEY STORAGE FACILITIES

Reservoir:	TIE HACK (or LITTLE SOURDOUGH ENL OF 9489R)
Date:	28 Feb. 2001
Location:	SESE 23,T50N,R84W
Owner:	CITY OF BUFFALO
Year of Construction:	1997
Total Storage:	2,435 acre-feet
Active Storage:	1,647 acre-feet
Dead Storage:	2.6 acre-feet
Area/Capacity Data:	(Source: Permit on file with Safety of Dams Office, State Engineer's Office, Cheyenne)
	Elevation (ft) Area (acres) Ave. Area (acres) Incremental Capacity (af) Accumulated Capacity (af) 7315 0 0 0.007 0.035 7320 0.014 0.035 0.05 0.250 7325 0.085 0.285 0.09 0.450 7330 0.1 0.735 0.16 0.80 7335 0.23 1.54 0.3 1.50 7340 0.36 3.04 0.42 2.10 7345 0.49 5.14 0.68 3.40 7350 0.88 8.54 1.31 6.55 7355 1.74 15.09 2.72 13.60 7360 3.70 28.69 4.92 24.60 7365 6.13 53.29 6.79 33.95 7370 7.45 87.24 8.08 40.40 7375 8.72 127.64 9.50 47.50 7380 10.28 175.14 11.17 55.85 7385 12.06 230.99 13.43 67.15 7390 14.80 298.14 16.55 82.75 7395 18.30 380.89 21.30 106.50 7400 24.30 487.39 25.43 127.15 7405 26.56 614.54 27.94 139.70 7410 29.32 754.24 29.71 35.40 7411.19 30.10 789.64 31.35 119.40 7415 32.61 909.04 36.12 180.60 7420 39.36 1,089.64 41.93 209.65 7425 44.23 1,299.29 44.98 224.90 7430 45.72 1,524.19 47.77 238.85 7435 49.82 1,763.04 52.22 261.10 7440 54.63 2,024.14 57.59 287.95 7445 60.55 2,312.09 61.51 123.02 7447 H.W.L. 62.46 2,435.11 TOTAL CAPACITY, ENLARGEMENT = 788.44 A.F. TOTAL CAPACITY UNDER PERMIT 9489R = 1,646.67 A.E. TOTAL AVAILABLE CAPACITY = 2,435.11 A.F.
Dam Construction Type:	Concrete and other
Outlet:	48-inch conduit controlled by three 36-inch and two 48-inch sluice gates with a flow capacity of 740 cfs.
Spillway:	50-foot slot in concrete crest.
End-of-Month Storage Records:	No
Water Rights:	(Source: Tabulation of Adjudicated Surface Water Rights of the State of Wyoming, Water Division Number Two, Oct. 1999.)
	Reservoir Permit Number Permitted Use Priority Date Volume (af) Headgate Location (S-T-R) Tie Hack Res. 9489R Mun, Power, Fish prop., Rec. 10-18-1933 1646.67 23-50-084 Enl. Tie Hack Res 9700R Rec 09-12-1989 788.44 23-50-084
Designated Use:	Water supply and hydropower
Recreational Use:	Fishing, non-motorized boats, picnic area
Associated Irrigation Diversions:	All irrigation from Tie Hack Reservoir is accommodated by the City of Buffalo through its city intake.
Associated Industrial Diversions:	The City of Buffalo's storage in Tie Hack Reservoir supplements direct-flow rights for a small hydroelectric generator at the end of four miles of pipe installed to terminate just upstream of the city's treatment plant.
Operational Discussion:	Tie Hack Reservoir is situated on the confluence of the South Fork of Clear Creek and Sourdough Creek. As an on-channel facility, Tie Hack is required to bypass at least 6 cfs into the South Fork of Clear Creek.
	As of February, 2001, Tie Hack has not yet had a release to the Town of Buffalo. In part, this is because the stored water supplements Buffalo's direct flow rights. But this is also because the town has a 150 acre-foot exchange in Willow Park for direct flow in Clear Creek – which is used before Tie Hack water.
	The operator is also required to maintain a 700 acre-foot fish pool in the reservoir.
References:	Carmine Loguidice, State Engineer's Office Water Div. 2 water commissioner, interview, 20 Feb. 2001.
	Ken Gross, Town of Buffalo administrative assistant, interview, 28 Feb. 2001.
	Active Dams, State Engineer's Office Safety of Dams Engineering Div. Database, transmitted by Larry Stockdale, Safety of Dams engineering consultant, 16 Feb. 2001.
	Tabulation of Adjudicated Surface Water Rights of the State of Wyoming, Water Division Number Two, Oct. 1999, database transmitted by Rebecca Mathisen, SEO Technical Services Division administrator, 8 Sept. 2000.

Net Evaporative Loss from Tie Hack:

Tie Hack Reservoir End-of-Month Storage

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Wet (1997)	2450	2450	2450	2450	2450	2450	2450	2450	2450	2450	2450	2450
Average (1999)	2450	2450	2450	2450	2450	2450	2450	2450	2450	2450	2450	2450
Dry (2001)	2450	2450	2450	2450	2450	2450	2447	2241	2014	2034	2079	2055
Historical Ave. Storage (acre-feet)	2450	2450	2450	2450	2450	2450	2449	2380	2305	2311	2326	2318
Corresponding Area (acres)	54.63	54.63	54.63	54.63	54.63	54.63	54.63	54.63	54.63	54.63	54.63	54.63
Calculations:
Monthly Lewis Evap. (inches)	1.296	1.2	1.872	3.84	5.52	6.288	8.208	7.488	5.52	3.648	1.872	1.248
Monthly Precipitation (inches)	0.75	0.75	0.75	1.75	2.75	2.25	1.25	0.75	1.75	1.25	0.75	0.75
Net Evaporation (inches)	0.546	0.45	1.122	2.09	2.77	4.038	6.958	6.738	3.77	2.398	1.122	0.498	TOTAL
Net Evaporation (acre-feet)	2	2	5	10	13	18	32	31	17	11	5	2	148

Note: Because Tie Hack Dam was completed so recently, its records were culled for the wet, average, and dry years identified by Wyoming State Engineer's Office water commissioner-hydrographers. These were averaged to provide the basis for the evaporative loss calculations.