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PRIORITIZING STORMWATER CAPITAL IMPROVEMENT PROGRAM (CIP) PROJECTS APWA Fall Joint Conference| Kearney, NE | November 6th , 2013 Presented by Lalit Jha, PE, D.WRE, CFM Miles Simmons, EIT, M.S. 1 Agenda • Urban Drainage Issues • CIP Prioritization • Study Methodology • Project Benefits • Conclusion 2 Urban Drainage Issues • Flooding Problems • Structural Condition of the System • System Upgrades and Master Planning • Operation and Maintenance • Stormwater Program Financing 3 Localized Flooding 50th and R St. 63rd and Fletcher Ave. 4 Stormwater System Deficiencies 27th and Highway 2 33rd and Highway 2 5 Structural Condition 14th and Holdrege St. 11th and Oak St. 6 Urban Drainage Issues “How can drainage problems be identified?” “Which problems should be addressed first?” “What are the financing needs?” “Most bang for the buck” 7 Background – Lincoln, Nebraska • • • • • • State Capital, second largest City in NE Population 260,000 82 square miles within City limits 500 miles of public storm drain system 230 miles of open channel system 31,000 ancillary items 8 Background – CIP Prioritization • Previous methodology developed in 1966 • Based on out‐dated standards • Reactive approach “Squeaky wheel gets the grease” 9 Project Objective • Develop an updated prioritization methodology and a proactive CIP • Identify stormwater CIP projects • Enhance the City’s stormwater database “Reduce Flooding and Drainage Issues” 10 Prioritization Approach • Written Scoring • Written Policy • Engineering Judgment / Committee Review 11 Prioritization Methodology • Prioritization Categories • • • • Structural Flooding Non‐Structural Flooding Existing Infrastructure Condition Miscellaneous Factors health and safety critical locations downstream impacts community development links to other utility projects 12 Prioritization Methodology Example Prioritization Worksheet 13 Previous Study Process • Data Preparation / Data Collection • Identify Deficiencies – MicroStation GeoPak Drainage – 1‐D, Rational Method, steady flow • Propose Drainage Improvements • Prioritize Projects • GIS Coverage and Database – Imported from MicroStation 14 Application • Studied 10,000 acres of watershed • 135 miles of pipe, 20,000 LF of open channel, 5,000 ancillary items • Identified 150 CIP stormwater projects – Dozens of projects proceeded to design/construction through funding from 2005‐2012 Stormwater bonds 15 Current Urban Drainage Study 16 Current Study Process • Phase 1‐ Screening Level Analysis – 1‐D, Rational Method, steady flow – Identify Storm System Deficiencies • Pipe Capacity, Inlet Ponding Depths, Ponding Limits, Structural Flooding – Update GIS Database • Phase 2‐ Detailed Analysis and CIP Development – Optional 2‐D, unsteady flow – Develop CIP stormwater projects • Evaluate conceptual alternatives 17 Hydrology and Hydraulics Screenshot of DGN map ArcGIS XP SWMM 18 Stormwater System Deficiencies Drainage system deficiencies based on design storm as defined in City design criteria manual. Pipes (Discharge Relative to Capacity) Inlets (Ponded Depth at Inlet) Ponding Areas (Structural Flood Frequency) Street Flooding 19 1-D/2-D Analysis 1-D Pipes/Open Channels 2-D Overland Flow/Flooding 20 Flooding Animations 21 CIP Project Development • Structural Flooding • Location • City Design Standards • Cost-Effectiveness 22 CIP Project Development 23 CIP Project Prioritization 24 GIS Database Management 25 GIS Database Management 26 Model Validation 27 Conclusion • Cost‐effective approach to prepare a proactive stormwater CIP • Ensures taxpayers’ dollars spent on most needed projects • Helpful in justifying stormwater program financing needs to elected officials and public 28 Thank You! Questions? 29