BOARD01897 - Laserfiche WebLink

Home Browse Search

:;"j The Peterson Ditch is decreed for 534 cfs under two separate decrees, but the diversion records for e the past eight years indicate that 101 cfs was the l\1aximum diversion that has occurred. The second decree, which is junior to the compact, has not been utilized and is on the list for abandonment. The operator of the ditch indicated that there also is a possibility of diverting flows for this project via the Peterson Ditch during the spring runoff, Diversions during the spring runoff period would not be consistent, due to the fact that diversions would be dependent upon the available capacity of the ditch after the ditch shareholders flow requirements were met. An alternate to allow diversions when shareholders are using the capacity of the ditch is to enlarge the capacity of the ditch in the reach from the riv~r to the reservoir to accommodate the junior fill decree of the res~rvoir. This would insure no injllry to present users under the ditch. It is estimated that an enlargement would run between 30 to 50 ds of capacity. There are many issues associated with this that need to be addressed, The Julesberg Irrigation District is key in any use of this structure and will need to give approval for any proposed modifications, This alternate will need further study during the preliminary design phase, The present configuration of the Peterson Ditch diversion structure is capable of diverting all flows from the main stream of the South Platte River up to ditch capacity, The structure is a wood sheet pile structure with a concrete cap. The structure for the Peterson Ditch is apparently in poor condition and there is a concern that the structure is in need of replacement. The general concem is that the streamb~d is degrading downstream of the structure, which eventually could cause the structure to fail. It is unknown at this time if any corrective action is slated to repair or replace the diversion structure. The location of the Peterson Ditch, and the fact that the ditch would be able to pl'()vide a gravity ... supply, make it ideal for a water supply source for the proposed reservoir. .. Although the Peterson - Ditch will not b~ capable of filling the reservoir to the high water line, the ditch will be able to fill approximately 75% of the reservoir's capacitY, efficiently and cost effectively. Certain limitations are associated with using the Peterson Ditch to deliver water to the reservoir. The . diversions through the Peterson Ditch will primarily occur during the winter months when sub- freezing temperatures are possible. Freezing temperatures could prevent diversions due to icing and the possibility of ice jams. The timing of diversions may help eliminate this problem, There is a fairly lengthy time period during the winter months when the flows in the river are high enough to support this re-regulation project. It appears there is sufficient time in moderate temperatures to divert a full supply to the reservoir. The second option for diverting flows into the reservoir are the GASP "Ovid Wens" which are located directly south of the proposed site (See Figure 2). The three wens were originany constructed in 1977, The west wen was washed out by the river and was replaced in 1984. The wens as they are presently equipped are capable of delivering 20 cfs (8980 gpm) to the reservoir site under the fonowing technical assumptions listed in Table I: Table 1 - GASP Ovld Wells Technical Data Conditions of Service ICOS\ Wellldentificatlon easln" Size Pumn Motor Oischame Tolal DYnamic Head Efficienl'!\l West Well 18" 16" -1 S"'.e 1000HP 3750 ~m 85 feet 84% Middle Well 16" 14" -2S,,",e 60HP 2750 onm 85 feet 83% East Well 16" 14" -2Stal!e 60HP 27S0l!1)m 85 feet 83% e 5