Accession Number : ADA581189
Title : Assessment of the Water Quality Conditions at Ed Zorinsky Reservoir and the Zebra Mussel (Dreissena polymorpha) Population Emerged after the Drawdown of the Reservoir and Management Implications for the District's Papillion and Salt Creek Reservoirs
Descriptive Note : Special rept.
Corporate Author : CORPS OF ENGINEERS OMAHA NE
Personal Author(s) : Hargrave, John ; Jensen, Dave
Report Date : 23 Apr 2012
Pagination or Media Count : 126
Abstract : LOCATION AND DESCRIPTION Ed Zorinsky Reservoir (Zorinsky Lake) is located in Douglas County in eastern Nebraska. The reservoir is located entirely within the city limits of Omaha, the largest city in the State of Nebraska. The dam that forms Zorinsky Lake is located on Box Elder Creek, a small tributary stream in the West Branch Papillion Creek basin. The dam was completed on July 20, 1984; however, potential water quality problems delayed closure. Two wastewater treatment facilities occasionally discharged to tributaries upstream of the reservoir and it was decided to delay final closure until the situation was addressed. The situation was corrected by constructing a diversion pipeline to the Elkhorn River in the fall of 1989. The low-level gate at the dam was closed on December 7, 1989 and the reservoir reached its initial fill in April 1992. Table 1-1 gives selected engineering data for Zorinsky Lake. When built, the full multipurpose pool of Zorinsky Lake was 1.5 miles long and had a surface area of 259 acres, a storage capacity of 3,037 ac-ft, and a mean depth of 11.7 feet. The reservoir s watershed is 16.4 square miles, and was largely agricultural when the dam was completed in 1984. However, the watershed has undergone extensive urbanization with the growth of Omaha over the past two decades. It is estimated that about 8-10 percent of the as-built multipurpose pool volume of Zorinsky Lake has been filled from sedimentation. The reinforced concrete intake structure at the Zorinsky Lake dam has four upper-level intakes (two at invert elevation 1110.0 ft-NGVD29 and two at invert elevation 1117.6 ft-NGVD29), an intermediate-level intake (invert elevation 1104.3 ft-NGVD29), and a low-level intake (invert elevation 1090 ft-NGVD29). The upper-level intakes are uncontrolled. The intermediate-level intake has a 6-inch diameter slide gate for flow augmentation releases for water quality management.
Descriptors : *MUSSELS , *RESERVOIRS , *WATER QUALITY , DEPTH , FISHES , HYPOXIA , LAKES , PH FACTOR , PHYTOPLANKTON , TURBIDITY
Subject Categories : Biological Oceanography
Hydrology, Limnology and Potamology
Water Pollution and Control
Distribution Statement : APPROVED FOR PUBLIC RELEASE