HomeMy WebLinkAbout12 Water Depletion methods
TDPUD STAFF REPORT
April 10, 1998
To: Board of Directors
From: Peter L. Holzmeister
Subject: Analysis of water depletion methods
AGENDA # 12
I have reported to you before that negotiation of the Truckee River Operating Agreement has
resulted in our water allocation being subject to a depletion limitation. We do not understand
how the depletion will be calculated and we do not understand the impact depletion will have on
our ability to use 32,000 acre feet of water each year. It would be beneficial to evaluate these
issues before TROA is signed.
Attached is a proposal submitted by Placer County Water Agency asking that our District
participate with several other agencies in a joint evaluation of these issues. The total cost of the
analysis is $30,000. It is suggested that we pay $7,000 of that amount.
Let’s spend a few minutes reviewing this issue. The Settlement Act adopted by Congress
allocates a gross diversion of water in the amount of 32,000 acre feet per year to the California
portion of the Truckee River Basin. The negotiated TROA places a limit on the 32,000 acre feet.
It says that water users in the California portion of the Truckee River Basin must return to the
river 15,500 acre feet of the 32,000 acre feet. In other words, we can use 32,000 acre feet of
water each year provided that, after we use it, at least 15,500 makes its way back to the river
system.
The fact is that when we use water, much of it does return to the river. Water that goes into
sewers goes through the TTSA plant and gets into the river. Some of the water that we put on
our lawns sinks into the soil and returns to the groundwater basin, which connects to the river.
So, making a commitment to return 15,500 acre feet of water to the river may not be a problem.
But we do not know with any level of confidence unless we do an analysis. I think that doing the
analysis is a good idea.
I have discussed this with Pat Sutton because we both are active on the committee that is
negotiating the TROA. Pat has followed these issues from the beginning. Pat and I are both
concerned that the depletion concept found its way into the TROA at all. We blame the State of
California staff for agreeing to it against our wishes. Because this entire issue results from a
State of California blunder and because the State is ultimately responsible for bearing the
burden of negotiating TROA, Pat feels, I think, that the State should bear the cost of this
analysis. I agree with her basic premise, but I am worried that the State will simply refuse to do
the study. It is better that we pay for the study and get it done, than have no study done at all.
We should discuss this at the meeting on Wednesday evening.
PLH/smc