SCH Number 2000121077

Project Info

Title

Segunda Deshecha Canada Channel Improvements IP 00-164

Description

CDFG is intending to execute a Lake and Streambed Alteration Agreement (SAA #R5-2001-0067) pursuant to Section 1601 of the Fish and Game Code to the project applicant, County of Orange, Planning & Development Services Department. The applicant proposes to alter the streambed to replace the existing 12 to 16 foot variable width concrete trapezoidal channel with a 20.7 foot wide by 10 foot high single barrel box culvert between El Camino Real and Avenida Pico located in the City of San Clement. The length of this section is 400 feet. Upstream of Avenida Pico, the existing 12 to 16 foot concrete trapezoidal channel will be replaced with an 18 foot wide reinforced concrete open rectangular channel. Channel wall heights in this section will vary bewtween 9 feet and 15 feet. The length of this open channel section which runs from Avenida Pico to the terminus of the project, is 3,600 feet. Thus, the total length of streambed impacted by this project (from El Camino Real to the project terminus) is 4,000 feet. A maintenance path and/or maintenance road will be construced adjacent to the channel within the existing concrete right-of -way. In additiion, the Operator proposes constructing a water diversion structure within the stream channel in anticipation of a proposed water quality enhancement project to be developed and implemented by the City of San Clemente. The applicant's mitigation measure include: construction of twelve sediment retention bumps ("speed bumps"), four inches (4") high, along the concrete bottom to allow sediment to be trapped and remain in the channel druing low flow periods, for the purpose of providing a substrate for wetland plants and animals; installation of a trash debris boom downstream of Calle de Los Molinas to remove debris associated with the "first flush": and construction of slots in the downstream section of the channel invert and channel walls near Avenida Pico to provide a secure point to install removable barricades - to dam the channel and prevent hazardous materials or sewage spill from reaching the ocean if necessary.

2 documents in project