CHATFIELD RESERVOIR REALLOCATION STUDY/PROJECT

By Marge Price and David Howlett
Capitol Representatives

The plan to reallocate storage space in Chatfield Reservoir is moving forward.  The draft Environmental Impact Statement is almost complete.  The next big step in this critically important water suplly project will be a public comment period which is expected to occur as early as July of this year.

Congress authorized the reallocation of Chatfield storage space in the aWater Resources Development Act of 1986.  The U. S. Army Corps of Engineers realized within a decade of completion of the reservoir that there was additional usable capacity there.  It has taken 25 years to get this project close to reality.  In all that time, the need for additional water for the Front Range has also been well known.  Efforts to conserve water have doubled and redoubled.

Measuring remaining groundwater sources now in use has shown that drawing water from underground aquifers is a finite source and is not sustainable in the longer term.  Chatfield Reservoir was built after the massive 1965 flood as a flood prevention and control facility.  Its placement, at the confluence of Plum Creek and the South Platte River, was chosen as a flood control and prevention measure, but it is also efficient for delivering water to the reservoir for storage.

The Greenway Foundation joined with four downstream water providers in 2005 to push for additional water storage in Chatfield Reservoir when efforts through the U. S. Army Corps of Engineers were already underway regarding an Environmental Impact Statement.  Preliminary studies leading to the EIS began in 1997 and work on the actual EIS was initiated in 2004.  The non-federal sponsor for the project is the State of Colorado through the Colorado Water Conservation Board.

The Greenway Foundation continues to serve as the administrator for the coalition.  Jeff Shoemaker, Executive Director of the Foundation, leads a coalition of Chatfield Reallocation advocates on biannual excursions to Washington, DC to visit the Colorado congressional delegation and lobby for federal funds.  The excursions also include meetings with the U.S. Army Corps of Engineers headquarters experts on a broad range of technical benchmarks.  The Chatfield Reservoir Reallocation Coordinating Committee is appreciative of the solid and broad-based support by the Colorado congressional delegation.  All members have been very supportive of the effort to complete the FR/EIS study.

The Chatfield cooperators group has grown to include more than 30 entities including upstream water providers, downstream water providers, instream interests, 14 state and local government stakeholders and 7 non-profit organizations.

In 2010, the downstream water providers and others resumed work on a parallel local effort to assess the potential environmental benefits of timing water releases from Chatfield once the additional storage is available.  The Greenway Foundation, water providers, environmental organizations and other advocates are working together to coordinate the releases in a manner that provide environmental and recreational benefits to the South Platte River corridor as the water travels along the River through the Denver metro area.

The Chatfield Reservoir Reallocation study has been funded via a 50%/50% cost share agreement between the U. S. Army Corps of Engineers and the State of Colorado.  The local water providers will be responsible for the environmental mitigation costs of increasing water storage and the recreational modification costs to Chatfield State Park that will be needed to accommodate the additional water.  In addition, the local users will pay the federal government for the cost of storage, estimated to be $14 million.  In all, the costs borne by the water users will come to more than $100 million.  Less than $3 million will be paid by the federal government.