Green Infrastructure Modeling in Cincinnati Ohio. Small Scale Green Infrastructure Design Using Computer Modeling

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1 Green Infrastructure Modeling in Cincinnati Ohio Small Scale Green Infrastructure Design Using Computer Modeling

2 Presenters Jason Abbott is a Design Engineer with over 17 years of experience. Jason is a professional engineer with a BS from Ohio State University. Leah Buerman is a water resources engineer with over 5 years of experience. Leah is a professional engineer with a BS and an M.Eng from Cornell University.

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4 Mill Creek & West Fork Branch Watersheds

5 West Fork Branch Watershed Characteristics 6,000 Acre Watershed 1,500 Acres Mt. Airy Forest 15 CSOs 12,800 LF of Natural Channel 12,000 LF of Rectangular Concrete Channel Hydraulically Connected Through 18 Grated Inlets

6 West Fork Branch Sustainable Watershed Project Alternative Analysis Report

7 Enabled Impact Projects Since 2009, MSD has partnered with public and private entities across Hamilton County to demonstrate the use of effectiveness of various stormwater controls. This program known as the Enabled Impact Program enables MSD to fund or help fund stormwater controls on partner sites - MSD Project Groundwork

8 Terminology Rain Garden - (also known as bioretention or bioinfiltration cells) shallow, vegetated basins that collect and absorb runoff from rooftops, sidewalks, and streets. Rain gardens mimic natural hydrology by infiltrating and evapotranspiring runoff. Rain gardens are versatile features that can be installed in almost any unpaved space. Bioswale - vegetated, mulched, or xeriscaped channels that provide treatment and retention as they move stormwater from one place to another. Vegetated swales slow, infiltrate, and filter stormwater flows. As linear features, vegetated swales are particularly suitable along streets and parking lots. Source: EPA

9 Green (Enabled) Project Opportunity Grants OEPA - SWIF OEMA OEPA Clean OH Partners Cincinnati Parks Board Ground Work Cincinnati - Mill Creek Northside

10 Partnering & Grants Mt. Airy Wetland Redevelopment OEPA - Surface Water Improvement Fund (SWIF) Grants Program

11 Partnering & Grants Flood Plain Enhancement Ohio Emergency Management Agency: Pre-Disaster Mitigation Grant Clean Ohio Fund: Clean Ohio Green Space Conservation Grant

12 Six Enabled Impact Projects Evaluated in the West Fork Branch Sewershed GOAL: Implement green infrastructure within the community to reduce stormwater runoff and consequently CSO volume at the downstream CSO s

13 Computer Modeling of Enabled Impact Projects GOAL: Evaluate the potential reduction in stormwater runoff volume achieved through the implementation of each green infrastructure project. Identify the placement of the most effective and cost efficient green infrastructure within the community Software: PCSWMM - EPA SWMM 5 (Storm Water Management Model Version 5) Engine Rainfall: Typical Year Rainfall - a modified version of the 1970 rainfall for Cincinnati, Ohio

14 Green Infrastructure Modeling Techniques Rain Gardens modeled as storage nodes. Void space of the rain garden subbase was included in the total volume of the storage node. Bioswale modeled as a trapezoidal channel Conservatively minimal infiltration was included in the model at the green infrastructure locations. Suction Head, in Hydraulic Soil conductivity (in/hr) LB1

15 Slide 14 LB1 ten in of suction head is conservative assumes siilty clay / clay soils. 0.5in Hydraulic soil conductivity is also for clay soils Suggest that Field testing is preferred to determine soil characteristics Leah Buerman, 8/22/2014

16 Mt. Airy Wetland Redevelopment

17 Area 2 Mt. Airy Wetland Redevelopment Proposed installation of three rain gardens in series located downstream of the Mt. Airy Forest (tributary to CSO 127). Drainage area is currently directly connected to the combined sewer system. Attributes Drainage Area = ac Proposed Rain Garden Modeled Surface Area = 30,594 sf Proposed Rain Garden Depth varies from 1.5ft to 4ft Proposed Rain Garden Total Volume = 53,700 cf Proposed Rain Garden Storage Volume = 4,269 cf The volume assumes that only the first 0.5ft of the rain gardens are used for storage.

18 Floodplain Enhancement

19 Area 4 Floodplain Enhancement Proposed installation of a bioswale and a rain garden in series located near West Fork Road (tributary to CSO 127) Attributes Drainage Area = 1.3 ac Proposed Rain Garden Modeled Surface Area = 6,721 sf Proposed Rain Garden Modeled Depth = 1.5ft Proposed Rain Garden Total Volume = 10,082 cf Proposed Rain Garden Storage Volume = 3,361cf The volume assumes that only the first 0.5ft of the rain gardens are used for storage.

20 Modeling Results Green Infrastructure Location Area 2 Area 4 Description Mt. Airy Wetland Redevelopment Floodplain Enhancement Total Annual Runoff Volume, MG Existing Proposed Volume Reduction Total: 3.99 Computer modeling can provide the necessary information to help identify the placement of effective and cost efficient green infrastructure within the community. Runoff reduction potential along with installation cost, education benefits, aesthetic improvements, etc. are used to determine GI placement and design.

21 Questions