DRAFT FINAL SAN DIEGO RIVER NATURAL RESOURCE MANAGEMENT PLAN May 2006 PREPARED BY PARK AND RECREATION DEPARTMENT CITY OF SAN DIEGO AND MERKEL & ASSOCIATES, INC. Adopted by San Diego City Council on ______________, by Resolution No. _________ TABLE OF CONTENTS SUMMARY ..................................................................................................................................................................1 1.0 INTRODUCTION...................................................................................................................................................3 1.1 Setting..................................................................................................................................................................3 1.2 Purpose ................................................................................................................................................................3 1.3 Objective..............................................................................................................................................................4 2.0 Agency Jurisdiction and Applicable Plans ..............................................................................................................6 2.1 Agency Jurisdiction .............................................................................................................................................6 2.2 Applicable City of San Diego Plans ....................................................................................................................7 Road and Utility Construction and Maintenance Policies ...............................................................................11 Fencing, Lighting, and Signage .......................................................................................................................12 Materials Storage.............................................................................................................................................12 Mining, Extraction, and Processing Facilities .................................................................................................12 Flood Control...................................................................................................................................................13 Land Use Adjacency Guidelines......................................................................................................................13 3.0 Existing Conditions ...............................................................................................................................................30 3.1 Geology and soils ..............................................................................................................................................30 3.2 Hydrology and Water Quality............................................................................................................................30 REGIONAL WATERSHED CONDITIONS......................................................................................................30 RIVER HYDRAULICS.......................................................................................................................................35 FLOOD HAZARD ..............................................................................................................................................37 HYDRAULIC CONDITIONS FOR THE LOWER PORTION OF THE NRMP AREA...................................38 WATER QUALITY ............................................................................................................................................40 3.3 Storm Drain Outlets...........................................................................................................................................42 3.4 Biological Resources .........................................................................................................................................52 VEGETATION COMMUNITIES.......................................................................................................................53 Diegan Coastal Sage Scrub..............................................................................................................................53 Southern Willow Scrub....................................................................................................................................54 Mule Fat Scrub ................................................................................................................................................64 Coastal and Valley Freshwater Marsh .............................................................................................................65 Alkali Marsh/Cismontane Alkali Marsh..........................................................................................................65 Open Water......................................................................................................................................................65 Non-native Grasslands.....................................................................................................................................66 Non-native Vegetation/Exotics........................................................................................................................66 Eucalyptus Woodland......................................................................................................................................68 Disturbed .........................................................................................................................................................68 Non-vegetated Channel/Rip-Rap.....................................................................................................................68 Urban/Developed.............................................................................................................................................68 FLORAL RESOURCES......................................................................................................................................68 ZOOLOGICAL RESOURCES............................................................................................................................69 Invertebrates ....................................................................................................................................................69 Fish ..................................................................................................................................................................69 Amphibians......................................................................................................................................................69 Reptiles ............................................................................................................................................................70 Birds ................................................................................................................................................................70 Mammals .........................................................................................................................................................81 WILDLIFE CORRIDORS...................................................................................................................................81 SENSITIVE SPECIES.........................................................................................................................................82 Plants ...............................................................................................................................................................83 Invertebrates ....................................................................................................................................................84 Amphibians and Reptiles.................................................................................................................................84 Birds ................................................................................................................................................................85 Mammals .........................................................................................................................................................92 Other Sensitive Species ...................................................................................................................................92 3.5 Cultural Resources...........................................................................................................................................100 i PREHISTORY...................................................................................................................................................100 REGIONAL HISTORY.....................................................................................................................................101 LOCAL HISTORY............................................................................................................................................102 RECORD SEARCH RESULTS ........................................................................................................................107 3.6 Land Use and Recreation.................................................................................................................................110 LAND USE AND RECREATION