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HomeMy WebLinkAbout3338; Agua Hedionda & Calavera Creek Dredging; Agua Hedionda & Calavera Creek Dredging & Improve.; 2005-11-01DRAFT INITIAL STUDY FOR THE AGUA HEDIONDA AND CALAVERA CREEKS DREDGING AND IMPROVEMENTS PROJECT CITY OF CARLSBAD Lead Agency: City of Carlsbad 1635 Faraday Avenue Carlsbad, California 92008 Attn: David Hauser, P.E. Prepared by: EDAW, Inc. 1420 Kettner Boulevard, Suite 620 San Diego, California 92 101 November 2005 TABLE OF CONTENTS Page PROJECT DESCRIPTION ........................................................................................................................... 1 1.1 Introduction .............................................................................................................................. 1 1.2 Environmental Setting .............................................................................................................. 1 1.3 Purpose and Need ..................................................................................................................... 5 1.4 Background and History of the Project .................................................................................... 7 1.5 Detailed Description of Project Components ........................................................................... 8 ................................................ 1.5.1 Dredging Activities and Infrastructure Improvements 8 . ................................................................. 1 5.2 Construction and Maintenance Activities 10 ...................................................................... 1.6 Future Operations and Maintenance Activities 11 1.7 Related Projects ...................................................................................................................... 1 1 ENVIRONMENTAL IMPACT ASSESSMENT FORM . PART I ........................................................... 15 LIST OF FIGURES Figures Page Regional Location Map ...................................................................................................................... 2 .............................................................................. Project Area and Adjacent Existing Land Uses 3 Floodplain Boundary Map <TBP> .................................................................................................... 6 Agua Hedionda Basin . Existing and Proposed Flood Control Projects .......................................... 13 .................................................................................................... Vegetation and Sensitive Wildlife 23 ................................ Agua Hedionda and Calavera Creeks ACOE and CDFG Jurisdictional Areas 27 BJB Basin - ACOE and CDFG Jurisdictional Areas ....................................................................... 29 General Plan Land Uses ................................................................................................................... 39 LIST OF TABLES Page 1 Quantity of ACOE and CDFG Jurisdictional Waters. Wetlands. and Riparian Habitat in Study Area .................................................................................................................................... 25 2 Typical Construction Equipment Noise (dBA) ................................................................................ 43 Agua Hedionda and Calavera Creek Channel Dredging and I~nprove~nents Project Initial Study Page i MN80103 Aguir IIcJior~du IS-drtr/r . JIIC 11/14/200> This page intentionally left blank. Page ii Agua Hedionda and Calavera Creek Channel Dredging and Improvements Project Initial Study OSIIROlOj Aguu lledionda ISSdraJi doc 11~/4/2007 PROJECT DESCRIPTION 1. INTRODUCTION The City of Carlsbad (City) proposes to conduct channel improvements and other infi-astructure modifications along Agua Hedionda and Calavera creeks to provide flood protection within the existing 100-year floodplain in the residential community of Rancho Carlsbad, in the northeastern section of Carlsbad, California (Figure 1). The City is fbnding and implementing the project's planning, design, and construction. Once dredging and construction activities are complete, the City will be responsible for maintenance of the improvements. The City is the project proponent and lead agency under the California Environmental Quality Act (CEQA). This Initial Study has been prepared pursuant to Section 15063 of CEQA to determine if the project may have a significant effect on the environment. Per the requirements of CEQA, the City will use the information in the Initial Study to determine whether there is substantial evidence that the project, either individually or cumulatively, may cause a significant effect on the environment, regardless of whether the overall effect of the project is adverse or beneficial. Based on this determination, the City will decide if preparation of an Environmental Impact Report (EIR) is warranted. The project boundary for the Agua Hedionda and Calavera Creeks Dredging and Improvements Project (project) is shown in Figure 2. As shown, the two creeks are adjacent to Rancho Carlsbad, an existing residential mobile home community located east of El Camino Real and south of Cannon Road. Both creeks flow in constructed earthen channels through Rancho Carlsbad. Agua Hedionda Creek flows westerly through the southern portion of Rancho Carlsbad from its downstream (southwestern) limit near Cannon Road Bridge to its upstream limit at Rancho Carlsbad Drive. Agua Hedionda Creek extends for a total length of approximately 1,400 feet. Two road crossings, Cannon Road Bridge and El Camino Real Bridge, are located in the downstream portion of the site. The confluence of Calavera Creek and Agua Hedionda Creek occurs approximately 300 feet east of El Camino Real. Calavera Creek extends upstream from the confluence for a total length of approximately 3,400 feet. An existing concrete wall located along Calavera Creek splits flows to the north and south side of the wall. The project area is surrounded by existing residential development, agricultural land, commercial uses, and open space (Figure 2). 1.2 ENVIRONMENTAL SETTING The project site is within the Carlsbad Hydrologic Unit. The entire Carlsbad Hydrologic Unit is a triangular area of approximately 210 square miles, extending from Lake Wohlford east of Escondido, west to the Pacific Ocean, and from Vista on the north to Cardiff by the Sea on the south. The Carlsbad 1 lagoons: Buena Vista, Agua Hedionda, Batiquitos, and t is further divided into six hydrologic areas (watersheds). within the City: Buena Vista Creek, Agua Hedionda Creek, a Hedionda and Calavera creekgare locatedwithin the Agua H-reek watemed. Agua Hedionda Creek is the principal drainage course of the approximately 24 square mile Agua Hedionda watershed. Agua Hedionda Creek originates in the hills south of the San Marcos Mountains and generally flows west, where it ultimately discharges to Agua Hedionda Lagoon, located approximately 1.5 miles downstream of the project site. Agua Hedionda Lagoon merges with the Pacific Ocean, and is considered Coastal Waters by the Regional Water Quality Control Board (RWQCB). Agua Hedionda and Calavera Creek Channel Dredging and linprovements Project Initial Study Page I OSOROlO3 Agua lledru~~ila IS-JraP doc llN4/21105