WSP00691 - Laserfiche WebLink

Home Browse Search

I I I I I I I I I I I I I I il I I I I to, ......', :-. ~ 0 ~) ~) to Trinidad Reservoir provides for the effects of this change in place of storage to be monitored by placing a water gauging station at a point in the Purgatoire River below the Project area located near the Colorado Interstate Gas Company pumping station which is presently known as the Thatcher gauge. The Decree provides that the storage of water in Trinidad Reservoir under the Model storage right shall be regulated in such a manner that the flow occurring at the Thatcher gauge shall remain and be the same as it would have been had the place of storage of the Model storage right not been changed to Trinidad Reservoir. Reclamation believes that from the requirements ofthi.s Decree, a comparison of pre-Project depletions of Purgatoire River flows in the Project area and post project depletions in the Project area at the Thatcher gauge is an appropriate method of analyzing effects of Project operations on the flows ofthe Purgatoire River. 1. Excess Storage Capacity In 1986 the COI1JS developed an updated elevation, area, capacity table based on a hydrographic survey of the reservoir which revealed that the reservoir capacity was 11,467 acre feet more than was authorized by Congress to be constructed. The excess reservoir capacity is attributed to more accurate topographic data. The Corps had determined that the excess storage capacity may be needed for flood control because the Purgatoire River channel through the City of Trinidad had not been maintained to safely pass a flow of 15000 cfs. On June 9, 1988, the COI1JS advised the City of Trinidad and the District that the channel capacity through Trinidad had been re-established to 15000 cfs except for the Linden Street low water crossing and upon removal of that structure, the excess storage space could be reallocated for other pUI1Joses. The COI1JS and Reclamation jointly notified the District in October of 1988 that reallocation of the 11