Stenner Creek Fish Passage Repair Project

Stenner Creek Fish Passage Repair Project

In 2001, two rock weir structures were installed in the stream bed to create pools to enhance fish passage through the channel. Repairs were made to the weirs in 2002. Water has undercut a concrete road bed adjacent to the left bank (looking downstream) of the stream and enables water to bypass the channel by going under the road bed and then going subsurface for approximately 20 yards. The proposed project would stabilize the road bed and help concentrate flows in the channel. A narrow concrete apron extends from the road bed along the left bank of the stream. At the upstream end of the project site, a shallow trench would be dug using hand tools and wooden forms constructed parallel to the stream channel and under the apron of the road bed. At the lower end of the project site, wooden forms would be built under the apron without having to dig a trench. Holes would be drilled in the concrete road bed and concrete would be pumpe from a truck stationed on adjacent agriculture road, outside of the stream channel, into the holes to provide a sturdy base for the road and to prevent water from flowing under and undermining the road. Several serpentine boulders at the lowest end of the project site would be removed and replaced with comparable sized but heavier granite boulders to protect the road bed from lateral scours that may be caused by eddying currents. At the upstream end of the project site, water flows through a box culvert under Highland Drive. A series of offset baffles in the culvert help concentrate flow and enhance fish passage through the culvert. At the downstream end of the concrete apron exiting the culvert, two low concrete baffles would be added to concentrate flow in the middle of the stream channel, thereby providing attractant flows for steelhead during low flow periods. All work would be done when the stream is dry and devoid of water. The project is necessary to enhance steelhead passage at the site by preventing flows from going subsurface under the road and bypassing the channel. Issuance of a Streambed Alteration Agreement Number 1600-2004-0308-3 pursuant to Fish and Game Code Section 1602.

San Luis Obispo

San Luis Obispo