Water Supply Conditions
July 9, 2008

The allocation to water users for this year is currently at 75 percent.  We project Lahontan Reservoir to drop to about 65,000 acre-feet by the end of July and to about 23,000 acre-feet by the end of August, reaching 4,000 acre-feet in early to mid September.  When Lahontan Reservoir reaches 4,000 acre-feet, releases from Lahontan will be discontinued until mid-October, and resumed until November 15.  Projected July releases are 49,400 acre-feet.  

Lahontan Reservoir end of June storage was 110,009 acre-feet at elevation 4138.42 feet.  A full reservoir at the crest elevation of 4162.00 feet is 289,700 acre-feet.  The OCAP storage target for the end of June was 200,000 acre-feet.  The OCAP storage target for the end of July is 170,000 acre-feet.  Full diversions from the Truckee River for July are allowed, up to 350 cfs.  

The maximum diversion allowed is 350 cfs, which is more than is available of the Floriston Rates water.  For July, the Floriston Rates is 500 cfs, plus 100 cfs of fish water released from Stampede Reservoir.  This fish water must pass below Derby Dam and is not available for use by TCID water users.  In addition to the fish water, 34 cfs is required to be released below Derby Dam for Claim 1 agricultural water for the Pyramid Lake Tribe, and 81 cfs is required to be released for the unused portions of Claims 1 and 2, for a total of 215 cfs below Derby Dam.  After use in the Truckee Meadows, and passing the required 215 cfs below Derby Dam, the remaining amount of Floriston Rates available for diversion into the Truckee Canal for the first nine days in July has averaged 213 cfs.  The amount flowing into Lahontan Dam, as measured at the Hazen gage on the Truckee Canal , has averaged 151 cfs, resulting in a 62 cfs depletion in the Truckee Division of the Newlands Project.   

Carson River inflow to Lahontan Reservoir measured at Fort Churchill for June was 13,200 acre-feet, about 24 percent of average.  This June inflow has been exceeded about 80 percent of the time.  Average inflow for June is 55,300 acre-feet.  

The June 1 NRCS forecast for April-July inflow at Fort Churchill for 2008 was 60,000 acre-feet, which is 34 percent of the average 178,000 acre-feet.  Actual inflow will be very close to this forecast.  

Releases from Lahontan Reservoir for irrigation for June totaled 31,400 acre-feet.  Last years release for June was 43,600 acre-feet.   

Diversions from the Truckee River into Lahontan Reservoir for June were 17,000 acre-feet at Wadsworth and 12,800 acre-feet at Hazen.  The releases below Derby Dam were 11,400 acre-feet, averaging 191 cfs.