FLOODC00270 - Laserfiche WebLink

I I I I I I I I I I I I I I I I I I I SECTION 5 lDENTlFICA TlON OF WATER RIGHTS AVAILABLE FOR STORAGE IN THE REALLOCATED SPACE AND DEVELOPMENT OF TARGET RELEASES Five entities, South Metro Water Users, Denver Water, Greenway Foundation, City of Littleton and Central Colorado Water Conservancy District, provided data regarding storable inflow and demand patterns to represent the four categories of use described in Section 4. 5.1 SOUTH METRO WATER SUPPLY STUDY P ARTlCIP ANTS' PROPOSED USE OF CHATFIELD RESERVOIR FOR CONJUNCTIVE USE South Metro Water Users propose to utilize water available to them from three primary sources for storage in reallocated Chatfield Reservoir storage space: . Reusable effluent flowing in Plum Creek downstream from the Castle Rock area. Inflow to Chatfield Reservoir under a junior or "free river" water right. Diversion to storage under the priority of a junior water right from the Blue River utilizing excess capacity in Denver's Roberts Tunnel system. . . Water from these sources would be used for both direct municipal use and as recharge to the Denver basin aquifers in a conjunctive use program. South Metro's consultant, Hydrosphere, has independently determined the water available for diversion to reallocated storage in Chatfield Reservoir under the priorities of the above water rights and has also determined the target releases from reallocated storage for the South Metro participants. These results are integrated into the modeling studies completed in this investigation. 5.2 DENVER WATER'S PROPOSED USE OF CHATFIELD RESERVOIR REALLOCATED STORAGE Denver Water proposes to utilize additional storage in Chatfield Reservoir as drought contingency supply. The Denver Water Board modeled the operation of the South Platte River under build-out conditions using their P ACSIM model on a daily time step. The results of this modeling effort, termed CHA TFREE, provided a set of storable inflow data under a junior water right or "free river" conditions to Chatfield Reservoir. These data Were provided to Brown and Caldwell for use in this investigation. Available flows for diversion to storage would be stored by Denver Water in reallocated storage for use during severe drought conditions. Denver Water would then make releases fTom the reallocated storage at a rate of 40 cfs until the available storage was depleted. These drought periods were modeled as 1954-57, 1963-65, 1966-67, 1977-78 and 1981-82. P:\Data\GEN\CWCB\Chatfield\Repon 11.02\RevisedChatReport 1 03\Report2 -03 .doc 10