Lower South Platte River Study

• Contractor Name: Colorado Water Conservation Board
• Loan Projects - Doc Type: Feasibility Study

Lower South Platte River Study
Colorado Water Conservation Board
December 2001
historic uses of the water, and downstream constraints to estimate storable flows at key
locations along the river. Annual target water supplies or yields that could be achieved from
storing some of the available flow under a junior water right were estimated. This analysis
included consideration of water conveyance options (gravity vs. pumping) and constraints on
' using conveyance facilities to fill the new storage space.
Permitting and regulatory requirements that could affect the implementation of storage
' projects were identified. Prior planning reports were consulted for their opinions on
permitting requirements, especially as they relate to the National Environmental Policy Act
(NEPA), Clean Water Act Section 404b, the Endangered Species Act, and County 1041
' regulations. The possibility of avoiding federal involvement in permitting was assessed.
' Structural elements to meet the overall project objective, and non-structural water
management measures that could contribute to meeting the objective, were identified. This
included an inventory of proposed projects in the region, identifying potential new storage
' sites and reservoir volumes, assessing the potential to enlarge existing reservoirs, identifying
fill and drain conveyance facilities and required pumping requirements and conveyance
' capacities, as needed. Field reconnaissance of the potential storage sites was performed. An
evaluation was undertaken to determine which storage options would best meet the water
supply objectives. The potential role of non-structural water management measures was
' assessed.
Alternative storage projects were evaluated and a"short-list" of alternatives was created for
' use in plan formulation. Information was gathered on each storage option, including: storage
volumes; conceptual designs for the dams; required conveyance facilities; building and road
' relocations, reservoir operation and expected yields of water from new storage; land
ownership; regulatory, legal and permitting issues; and estimated cost including a
preliminary estimate of total,annual costs.
' Once the alternatives were evaluated, several high-ranking alternatives were selected for
further evaluation based on an alternatives analysis/decision-making framework. This
' framework is based on project objectives such as minimizing total project cost,maximizing
operational effectiveness, and minimizing permitting and regulatory challenges. A
' preliminary implementation schedule for the preferred alternative(s) from feasibility through
construction was then prepared.
Finally, funding mechanisms for project implementation and institutional and management
options required for the funding options and long-term operation of the project were
identified. A preliminary assessment was made of the contracts or agreements that would
likely be required and court actions that would be needed for project implementation.
GEI Consultants, Inc. 1-3 01002 Dec 2001 Lower South Platte River Study