FLOOD02174 - Laserfiche WebLink

Home Browse Search

I I I I I I I I I I I I I I I I I I I TABLE OF CONTENTS Page 1 1 1 1 2 I SUMMARY The Study Area Hydrologic and Hydraulic Analyses Development of Alternative Plans Benefit Cost Analysis The Master Plan II-l III-l III-2 II GENERAL BASIN DESCRIPTION 3 III HYDROLOGIC ANALYSIS 6 General 6 Delineation of Basins 6 Rainfall 6 Computation of Runoff for Existing Channel Conditions 7 Computation of Runoff After Implementation of the Proposed Master Plan 7 III-3 III-4 IV HYDRAULIC ANALYSIS 13 DESCRIPTION OF THE ALTERNATE PLANS FOR DEVELOPMENT General Recommendations from the Phase A Report Summary V 14 l4 14 17 VI BENEFIT-COST ANALYSIS Determination of Flood Damages Determination of Benefits Evaluation of Costs Comparison of Costs and Benefits l7 17 l7 l8 20 III-l VII THE DRY GULCH MASTER PLAN General Comments Basis of Design Major Drainageway Planning Sheets with Descriptions of Proposed Improvements and Estimated Costs of Proposed Improvements 23 23 23 Sheets 1 of l8 through l8 of l8 IV-l VI-2 VI-3 Appendices Appendix A Appendix B Legal Opinion Tabulations of Agencies and Individuals Contacted During Preparation of Report a-l VI-4 a-4 References a-4 VI-5 VI-6 LIST OF FIGURES Page General Location Map, Dry Gulch and Tributaries 3 Projected Peak Discharges on Dry Gulch 8 Projected Peak Discharges on North Dry Gulch 9 Comparative Hydrographs of Floods Reaching the Intersection of Colfax Avenue and Garrison Street After Construction of Recommended Facilities lO Inflow and Outflow Hydrographs at Proposed Detention Pond After Construction of Recommended Facilities l2 LIST OF TABLES Page Total Rainfall in Storms of 200 Minute Duration on Dry Gulch 7 Damage Computation Summary l8 Average Annual Damages in Each Reach of Dry Gulch 19 Unit Prices Used in Construction Cost Estimates (April 1979) 19 Annual Unit Costs for Operation and Maintenance 20 Estimated Costs of Construction pnd Land Acquisition 2l Comparison of Benefits and Costs in Each Reach of the Dry Gulch !1aster Plan 22