OCWD Board of Directors

Cathy Green
First Vice President
Denis R. Bilodeau, P.E.
Second Vice President
Philip L. Anthony
Jordan Brandman
Shawn Dewane
Jan M. Flory, ESQ.
Dina L. Nguyen, ESQ.
Roman Reyna
Stephen R. Sheldon
Roger C. Yoh, P.E.
General Manager
Michael R. Markus
P.E., D.WRE.

Weir Pond Rehabilitation
Project Completed
November 2015
The Weir Pond Rehabilitation Project, which includes demolition and rebuilding of a flume and weirs 1 and 2 and the installation of new drain slide gates and pressure transducer systems, will be completed this month.

A weir is a structure typically built to regulate river flows. The Orange County Water District (OCWD; the District) manages four weirs and ponds, which make up the Weir Pond System.

The Weir Pond System removes sediment from Santa Ana River flows prior to delivery of the water into the District’s groundwater recharge basins. This de-silting process increases groundwater recharge by slowing the percolation decay rates caused by sediments in Santa Ana River water.

The existing weir ponds and their accompanying structures were constructed in the early 1970s. The need to replace the severely degraded flow measurement and transfer structures of the Weir Pond System was accelerated in fall 2012 when a partial structural failure of Weir 1 occurred. Construction of the Weir Pond Rehabilitation Project began in June 2015 and will be fully completed in November 2015.

The weir ponds are located immediately downstream of OCWD’s Imperial Headgates Facility, between Imperial Highway and Lakeview Avenue, and cover 33 acres. Their maximum storage capacity is 252 acre-feet of water. They are part of more than 20 facilities that cover more than 1,000 wetted acres and have a total storage capacity of approximately 26,000 acre-feet. OCWD carefully tracks the amount of water being recharged in each facility on a daily basis.

A new parshall flume was constructed approximately 100 feet further downstream of the old flume (which was demolished as part of this project). The new flume location helps the water being diverted from the Santa Ana River become less turbulent before flowing over the flume. The district will be able to monitor flow at the flume and at the new sharp-crested weir at Weir 2, which will receive more accurate readings when monitoring flow than the old Weir 2 design.

This project underscores OCWD's ongoing commitment to enhance its groundwater recharge system.