LITTLE ROCK DISTRICT CORPS OF ENGINEERS WATER SUPPLY

Transcription

1 US Army Corps of Engineers LITTLE ROCK DISTRICT CORPS OF ENGINEERS WATER SUPPLY One Corps Serving The Army and the Nation

2 Storage at Existing Lakes Basic Authority Water Supply Act of 1958 The Corps can Reallocate Storage At existing lakes for Municipal & Industrial uses. All Storage at existing Lakes is allocated to Flood Control, Hydropower, Water Supply, and Fish & Wildlife purposes. The Corps is responsible for flood operations. Southwestern Power Administration is responsible for hydropower releases.

3 Chief s s Discretionary Authority* Corps of Engineers may reallocate the least of 15% or 50,000 AF of the total lake storage. Reallocation must have no significant adverse effect on authorized purposes such as hydropower generation or flood control. * If the Chief of Engineers Discretionary Authority is used up, Congressional Action is required to reallocate storage

4 US Army Corps of Engineers Water Supply Facts US Army Corps of Engineers sells Storage, NOT Water. Quality and quantity of water is not guaranteed. Water supply storage cost is fully described in the Water Supply Agreement between the Federal Government and the customer One Corps Serving The Army and the Nation

5 US Army Corps of Engineers How do we get storage? A letter of request is submitted by the customer with required yield. (e.g., We need 6 mgd. ) If the requested amount is within the Corps discretionary authority, a study will be conducted to determine the amount of storage required to meet your requested yield. The Corps prepares a Water Supply Reallocation Report. Upon approval, agreement is signed between the Federal Government and the entity purchasing storage and payments One are Corps made. Serving The Army and the Nation

6 Authorized Purposes vs Storage Allocation

7 Corps Operated Reservoirs Authorized Purposes Flood Control Pool Hydropower Generation Water Supply - Quasi Purpose after Water Supply Act of 1958 Authorized Uses Recreation Fish and Wildlife Water Supply

8 Reallocation from Conservation Pool Flood Control Conservation Pool Hydropower Water Supply Flood Control Reallocation Conservation Pool Hydropower Water Supply Existing Modified

9 What Happens When Storage is Reallocated From the Conservation Pool? Storage is taken directly from Hydropower, 100% loss to the hydropower purpose. No change to flood operations, no change to down stream flood damage reduction. The top of conservation pool elevation does not change. Flood Control Storage is not impacted

10 Reallocation from Flood Control Flood Control Conservation Pool Hydropower Water Supply Flood Control Reallocation Conservation Pool Hydropower Water Supply Existing Modified

11 What Happens When Storage is Reallocated From the Flood Pool? The hydraulic/hydrologic performance of the reservoir changes. The yield of the reservoir becomes less efficient, i.e, the yield to storage ratio decreases. Due to the decrease in yield the hydropower purpose loses capacity resulting in a net loss even though more energy is available due to the increase in head on the dam.

12 What Happens When Storage is Reallocated From the Flood Pool? (continued) The conservation pool increases into the flood pool Flood Control Storage is decreased, therefore increasing the potential of flood damages downstream

13 US Army Corps of Engineers WHITE RIVER MINIMUM FLOWS STUDY One Corps Serving The Army and the Nation

14 WRDA 1999/WRDA 2000 Study Start April 2000 Reallocation Report Complete July 2004 Chiefs Report signed August 2004 Energy & Water Development Act February2006

15 WRMF WAY FORWARD The following requirements are needed before this project will be completely implemented: 1) Record of Decision for EIS must be signed. 2) Funding for construction of valves, siphons, bulkheads, and Empire Electric compensation needs to be secured. 3) Engineering and Design completed, and legal agreement between local officials and Arkansas Game and Fish is signed regarding Lakeside Facility modifications. 4) Complete Construction and Capture Storage.

16 Water Supply Storage Reallocation for the Mid Arkansas Water Alliance Greers Ferry Lake and Lake Ouachita, Arkansas U.S. ARMY CORPS OF ENGINEERS

17 Greers Ferry Lake Pertinent MAWA Reallocation Facts 18,730 AF, 15 MGD, Flood Pool Reallocation 0.6 ft Rise in Conservation Pool Elevation 14,721 AF of Discretionary Storage Will Remain Lake Ouachita 33,303 AF, 20 MGD, Flood Pool Reallocation 0.82 ft Rise in Conservation Pool Elevation 10,061 AF of Discretionary Storage Will Remain