Outline. Stormwater Retrofit Planning: A Tale of Two Basins

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1 Outline Why Stormwater Retrofits at the Basin Scale Ecology and the National Estuary Program Woodard Creek and Totem Lake Basins The 6 Steps of Stormwater Retrofit Planning Lessons Learned 2

2 Why Stormwater Retrofits? 3 Why Stormwater Retrofits? 4

3 5 Why Basin-Scale Retrofits? > Photo Credits: Left: concretetech.com; Right: Jensenstormwater.com National Estuary Program 6 Watershed Protection and Restoration Photo Credit: timesunion.com

4 7 Case Study #1: Woodard Creek Woodard Basin City of Olympia City of Lacey Lacey UGA Olympia UGA Case Study #2: Totem Lake 8

5 Steps for Retrofit Planning 9 10 Step 1: Set Restoration Goals Woodard Creek: Water Quality Bacteria Totem Lake: Water Quality Treatment and Flow Control

6 11 Step 2: Conduct GIS Analysis Data Gathering GIS Data Characterize Basin Coarse Screen: Potential? Focus on Opportunities Fine Screen: Parcel Based Weighted Criteria 12 Step 2: Conduct GIS Analysis Data Gathering Retrofit Goals Data Available Needed Gaps? Assumptions or Data Collection

7 13 Step 2: Conduct GIS Analysis GIS Data for Screening Ownership Vacant Parking Lot Planned CIP Redevelopment? Outfall Ditch/Stream Wetland Slope Other Critical Areas Infiltration Potential Pollutant Hot Spot Upstream Impervious Area Existing Facility Drainage Paths Utilities 14 Step 2: Conduct GIS Analysis Coarse Screening Opportunity Existing Facilities Pollution hot spots Available space Woodard Creek Totem Lake

8 15 Step 2: Conduct GIS Analysis Fine Screening 16 Step 3: Site Feasibility Site Description Drainage Area Unique Elements Utility Conflicts Critical areas Access Flooding, Groundwater Photo Documentation

9 17 Step 3: Site Feasibility Basin Comparison Rural Woodard Creek Basin 16% impervious Roadside ditches & culverts Narrow roadways, low ADT Onsite wells & sewage systems, overhead utilities Water quality concerns - bacteria Outside the UGA Urban Totem Lake Basin 45% impervious Piped stormwater networks High ADT, multilane roadways High potential for utility conflicts overhead and underground Flow control & water quality Redevelopment Potential 18 Step 3: Site Feasibility Potential Retrofit Site Rating Form

10 19 Step 3: Site Feasibility Stakeholder & Public Input Step 4: Develop Location-Specific Retrofit Concepts 20 Image credits: Filterra Contech; UIC Well - WSDOT

11 21 Step 4: Develop Location-Specific Retrofit Concepts 22 Step 4: Develop Location-Specific Retrofit Concepts

12 Step 4: Develop Location-Specific Retrofit Concepts Evaluate Sites Site Concept Performance Hydrologic & Hydraulic Water Quality Sufficient Space? 23 Design Feasibility Ownership Cost Step 4: Develop Location-Specific Retrofit Concepts Performance 24

13 25 Step 5: Rank & Prioritize Sites 26 Step 6: Implementation Planning Prioritize projects for funding Develop structure for public/private partnerships Plan for interaction between onsite LID and off-site facilities Plan for programmatic (nonfacility) actions Document restoration goals for performance measurement

14 Lessons Learned 27 Photo credit: wetland ParksofKirkland.com Resources & Questions 28 Center for Watershed Protection s (CWP) Urban Subwatershed Restoration Manual Series City of Kirkland s Juanita Creek Watershed webpage Surface_Water/Protecting_ Creeks Watersheds/Juanita_Creek_Watershed.htm City of Kirkland s Totem Lake Economic Development webpage King County s Juanita Creek Basin Stormwater Retrofit Analysis Thurston County s Woodard Creek Stormwater Retrofit Study webpage Water Quality Models available from EPA AHBL - NHC -