Trees to Offset Storm Water Tools:
Codes and Ordinances Audit Tool
The Codes and Ordinances Audit Tool assesses how extensively a municipality’s urban forest is able to contribute to stormwater management. It evaluates tree ordinances, development codes, and other related policies and practices. The audit requires collecting data and interviewing staff to analyze and score policies. The audit results identify opportunities to increase infiltration and to utilize trees for stormwater management and other benefits.
• Download the TSW_Codes_Ordinances_Review_Template (xlsx file)
Trees and Stormwater Calculator Tool
The Trees and Stormwater Calculator Tool can be used to estimate the quantity of stormwater captured by tree canopy for drainage areas of mixed landcover. Rough estimates of Nitrogen, Phosphorus and sediment load reductions provided by tree canopy are also provided. The tool can be used to simulate different scenarios of tree canopy loss or addition, and see the resulting changes in stormwater capture and nutrient load reductions. The tool is designed to help communities set realistic tree canopy goals and estimate the benefits of obtaining those goals.
Below is an example trees and stormwater calculator tool from Boynton Beach, Florida. For a new community, land cover data is needed (what areas are forested, what areas are paved etc.) to determine how much stormwater trees take up for different storm events. Technical instructions on setting up the tool with these land cover data are provided below. GIC can be hired to create landcover data and can integrate the trees and stormwater calculator tool into a project with your community.
• Example TSW Calculator Tool from Boynton Beach FL (xlsx file)
Setting Up Data for Your City to Use the Stormwater Uptake Calculator Tool: Once your community has land cover data, follow the instructions in the technical manual below to set up the calculator tool.
• Download TSW Technical Instructions here (pdf)
• Link to: YouTube Trees and Stormwater Training Videos.
• TSW Calculator — Blank Spreadsheet (xlsx file)
Urban Forestry Program Self-Assessment Tool:
All the trees growing within a city or town boundary comprise its urban or community forest. The urban forest is made up of publicly and privately owned trees, trees in parks and natural areas, street trees, trees on commercial properties, and trees in residential yards. These trees provide many benefits and should be managed as part of the community’s green infrastructure. The health of urban forests depends on proactive tree protection, proper tree maintenance, and tree planting to replace tree loss. GIC has created a tool to assess a community’s urban forestry program based on tree care standards in six categories:
- Data and Tracking
- Staffing
- Tree Codes
- Plans
- Community Engagement
- Funding
GIC created five tiers corresponding levels of care: The “tree” tier represents the most robust program. While, a small town may remain at the “roots” or “sapling” stage because of resource constraints, it could go all the way to the “tree” level by investing in its urban forest and establishing partnerships. By answering the questions in the interactive tool linked to below a community will receive a tally of points, from these points each community can determine which tier they fall into, then see what next steps can be taken to further develop their urban forestry program.
Debris Calculator Tool:
The Debris Calculator Tool provides estimates of vegetative debris generation from a storm event as well as an estimate of the size of a debris management site. The tool uses an equation developed by the Army Corp of Engineers which is composed of the following multipliers: Number of households, storm category, vegetation cover, commercial use and storm precipitation. Using these values, the tool can generate an estimate of debris generated +/- 30%. It is meant to be a simple tool that can help planners during a natural disaster when both time and attention are spread thin. There is a tab for city use and one for county use.