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Intent To Prepare a Draft Environmental Impact Statement for the Seven Oaks Dam Water Quality Study, San Bernadino County, CA

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Department of the Army, U.S. Army Corps of Engineers, DoD.


Notice of intent.


With the construction of Seven Oaks Dam, during and immediately after storm events, water flows into the pool of water impounded behind the dam may be turbid. Once water is impounded behind the dam, all water flowing in the Santa Ana River that enters Seven Oaks Reservoir must pass through that impoundment before being released at the dam. To the extent that water impounded behind the dam can have a higher level of sediment or algae than water flowing in the Santa Ana River below the Southern California Edison (SCE) No. 1 Powerhouse, the quality of water released from Seven Oaks Dam into the Santa Ana River may be reduced.

The purpose of the study is to evaluate the potential impacts, if any, of the Seven Oaks Dam regarding downstream water quality and to characterize upstream water quality. This will entail characterization of the water quality conditions that existed Start Printed Page 29129prior to dam construction and determination of how or whether the dam has contributed to water quality impairment as part of the “baseline conditions analysis”. After the analysis, future studies would be determined with the resource agencies, Local Sponsors, and Stakeholders.


Commander, U.S. Army Corps of Engineers, Los Angeles District, Environmental Resources Branch, CESPL-PD-RN, 915 Wilshire Boulevard, Los Angeles, CA 90017. Attention to Randy Tabije, Ecosystem Planning.


A public scoping meeting has been scheduled for Wednesday, May 31, 2006 at 7 p.m. at the San Bernardino County Flood Control District Offices, 825 East Third Street, San Bernadino, CA 92415.

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Randy Tabije, Environmental Coordinator, (213) 452-3871 or e-mail at

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1. Authorization

A specific appropriation to initiate the study was provided in the Energy and Water Development Appropriations Bill, 2006, approved May 18, 2005: “Santa Ana River Mainstem, California—* * *; and $1,000,000 is available for the Seven Oaks Dam Water Quality Study.

2. Background

The Seven Oaks Dam is part of the Santa Ana River Mainstem Project that provides flood control to downstream communities in three counties. All of the storage space (currently computed at 147,900 acre-feet) behind Seven Oaks Dam is allocated to flood control and estimated sediment deposition purposes. The basic plan of operation is to store flood runoff until the reservoir elevation at Prado Dam (35 miles downstream) peaks and starts to fall. The flood control and environmental operation plan for Seven Oaks Dam provides substantial incidental water conservation benefits. Flood events that normally sweep rapidly past water conservation diversion facilities are now captured by the dam, and released at rates that are much smaller than the inflow to the dam. The relatively slower release of flood runoff is also for a much longer duration than the natural flood event. The anticipated net result is a greatly enhanced capability for water agencies to divert flood runoff than without the dam.

3. Proposed Objectives

The purpose of this study is to evaluate the impacts, if any, of the Seven Oaks Dam and present an array of recommendations to achieve and sustain water quality to the pre-Seven Oaks Dam level(s). Based on the results of the water quality analysis, determinations would be made for the need of any further studies. No proposed alternative plans have been formulated to date. Proposed objectives are:

a. Identify links between water quality, water conservation, and other environmental impacts.

b. Identify degraded water quality and quantify the types and sources of pollution.

c. Develop targets for water quality, based on pre-dam conditions.

d. Inventory and evaluate a suite of structural, non-structural, and other measures capable of improving water quality.

e. Integrate planned and existing water-quality, restoration, and management programs with other Federal, State, Tribal (if applicable), and local programs and projects.

f. Recommend additional programs and projects needed for improvement of water quality.

g. Identify appropriate sources of funding.

4. Scoping Process

a. Potential impacts associated with the proposed action will be evaluated. Resource categories that will be analyzed are: land use, physical environment, geology, biological resources, agricultural resources, air quality, ground water, recreational usage, aesthetics, cultural resources, transportation/communication, hazardous waste, socioeconomic and safety.

b. Participation of affected Federal, State and local resource agencies, Native American groups and concerned interest groups/individuals is encouraged in the scoping process. Time and location of the Public Scoping meeting will also be announced by means of a letter, public announcements and news release. Public participation will be especially important in defingin the scope of analysis in the Environment Impact Statement (EIS), identifying significant environmental issues and impact analysis in the EIS and providing useful information such as published and unpublished data, personal knowledge of relevant issues and recommending mitigative measures associated with the proposed action. Those interested in providing information or data relevant to the environmental or social impacts that should be included or considered in the environmental analysis can furnish this information by writing to the points of contact (see ADDRESSES). A mailing list will also be established so pertinent data may be distributed to interested parties.

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Dated: May 9, 2006.

Alex C. Dornstauder,

Colonel, U.S. Army, District Engineer.

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[FR Doc. 06-4685 Filed 5-18-06; 8:45 am]