Policy 10-4 WATER PUMPING FROM WAURIKA RESERVOIR TO LAKE ELLSWORTH

DISTRIBUTION: Mayor and City Council

All Departments

SUBJECT: Water Pumping From Waurika Reservoir to Lake Ellsworth

PURPOSE: To achieve maximum yields of water supply from Lake Lawtonka, Lake Ellsworth and Waurika Reservoir, yet, minimize the amount of pumping required to achieve this goal.

BACKGROUND: Water for treatment and consumption is withdrawn from Lake Lawtonka at the Medicine Park Water Treatment Plant and from Lake Ellsworth and Lake Waurika at the Southeast Water Treatment Plant. . Lake Ellsworth water is transferred (pumped) to Lake Lawtonka in accordance with Council Policy 10-2. Waurika Reservoir water can be pumped to Lake Ellsworth. In order to maintain a lake elevation in Lake Ellsworth which permits pumping to Lake Lawtonka, pumping from Waurika Reservoir to Lake Ellsworth may be desirable. Records of the lakes levels indicate that a large rain can result in rises of three to six feet. Yields from the lake are maximized when levels are balanced to receive runoff from their watersheds. Pumping also helps achieve optimum use of the City’s Vested Water Rights at all lakes.

POLICY/

PROCEDURES: Pumping will be suspended when the level of Lake Ellsworth is 7 feet or less (i.e. at or above elevation 1228.00 feet) below the top of its gates year round. Weather and watershed conditions will be considered when implementing pumping procedures.

The Public Works/Engineering Director may use discretion in implementing this policy under the following conditions:

A. If the watershed is in a saturated condition whereby it could be fairly and reasonably assumed that additional rain would result in substantial runoff physically into Lake Ellsworth, then pumping may be reduced to a minimum in anticipation of favorable natural results.

B. Waurika Reservoir is at an elevation so low that further pumping will cause damage to the pumps (cavitation).

Such times when the pumping of Waurika Reservoir is necessary to achieve optimum use of the City’s Vested Water Rights

REFERENCES: None.

COUNCIL

APPROVAL DATE: October 14, 2008

EFFECTIVE DATE: November 1, 2008, and will remain in effect until rescinded.

RESPONSIBLE

DEPARTMENT: Public Works

___________________________

John P. Purcell, Jr.

Mayor

October 14, 2008

(CP 10-4, Amended, 11/01/2008, Prior Text)