Watershed Planning for Green Infrastructure Implementation through the GreenPlan-IT Toolset
The benefits for greening the urban landscape through Green Infrastructure (GI) are numerous, including water-quality improvements derived from filtering runoff pollution, reduction of urban flooding risks, and increased groundwater recharge. Other benefits include traffic calming effects, improvement of the bike/pedestrian environment, improved connectivity of green spaces (and habitats for birds and wildlife), as well as beautification of neighborhoods and increased property values. But how do we ensure that GI placement is optimized to yield the water-quality and flow reduction outcomes called for within the NPDES permits?
GreenPlan-IT is a planning level tool that is designed to support the cost-effective selection and placement of GI in urban watersheds. The GreenPlan-IT toolKit is comprised of four tools: (a) a GIS-based Site Locator Tool to map and rank potential GI sites; (b) a Modeling Tool to determine baseline conditions and project runoff and pollutant load reduction from GI scenarios; (c) an Optimization Tool that uses cost-benefit analysis to identify the best GI installation scenario within a watershed for achieving flow/load reduction goals; and (d) a Tracker that measures the anticipated effectiveness. Tool outputs are used by municipalities to develop watershed master plans to guide future GI implementation toward addressing water quality and quantity targets.
This presentation will offer the latest results from our use of the tool in engagements with San Francisco Bay Area cities. Furthermore, we will share our explorations on the frontier of multi-benefit green-infrastructure planning that can characterize opportunities for urban forestry, recreational value, and climate-change adaptation.
The GreenPlan-IT Site Locator Tool featured in the presentation is a freely available GIS planning tool designed for municipalities and their consultants. It can be used as a stand-alone tool or in concert with the modeling and optimization tools of the ToolKit. The tool works with ESRI’s software to produce customizable and useful planning-level maps that identify and rank the best locations to implement GI throughout their respective cities. These are maps backed by rigorous geophysical science while transparently accounting for local concerns.
The Locator Tool synthesizes a broad range of data that may otherwise be neglected during a planning process. In practice, the Site Locator Tool uses regional and local data sets to identify the most suitable areas for certain GI types; limits outputs to potential locations such as sidewalk planters and medians; divides locations into publicly and privately owned opportunities; removes inopportune locations such as wetlands and building footprints; and applies a custom ranking to all locations that reflects local priorities. It is versatile enough to accommodate a range of physical conditions and data availability. It facilitates input of local and regional data, and allows users to run only the parts of the tool that are appropriate to their current planning process.
The GreenPlan-IT Site Locator Tool has been used by the cities of San Mateo, San Jose, Sunnyvale, Oakland, Richmond, as well as Contra Costa County. Cities have found the tool to be useful for providing a transparent, repeatable analysis to support their GI planning processes. Before the Site Locator Tool, GI features were installed opportunistically wherever space or grant funding were available. The cities desired a tool that could overcome an otherwise incremental and costly approach to achieve reduction in stormwater flow and pollution.