The Feasibility Report and Environmental Impact Statement (FR/EIS) will consider four alternatives and evaluate the potential impacts and costs of each: a proposed alternative for maximum reallocation, an alternative for an intermediate level of reallocation, and two alternative scenarios if no action is taken at Chatfield Reservoir.These alternatives will be described in detail in the Draft FR/EIS, which will be made available for public review during a 45-day comment period. The alternatives are as follows:
1) No Action: New Storage Construction: This alternative refers to the determination that “no action” will occur at the project site (Chatfield Reservoir).Without reallocation, water users would use gravel pit storage and construct a reservoir in the area.
2) No Action: Non-Tributary Ground Water/Gravel Pits: Without reallocation, water users would continue their reliance on non-tributary groundwater (NTGW) and utilize gravel pit storage for surface water storage.
3) Reallocation for 20,600 AF storage: This is the alternative proposed by the CWCB on behalf of the water users.This reallocation option would raise the top elevation of the joint flood control-conservation pool by 12 feet to 5,444 feet m.s.l. As determined in the Flood Antecedent Study conducted by the Corps, storing 20,000 AF does not compromise the flood control function the reservoir is designed to achieve.
4) Reallocation for 7,700 AF storage: This reallocation option would raise the top elevation of the joint flood control-conservation pool by 5 feet to 5437 feet m.s.l.
Alternatives 3 and 4 would require changes to the operation of the reservoir and would have impacts on the existing recreational facilities and use levels, as well as on fish, wildlife and vegetation resources within Chatfield State Park.
Click here to see a map of the possible elevations of the joint flood control-conservation pool under reallocation alternatives 3 and 4.