Workshop and Project Plans
Free workshops for the Rainwater Harvesting Rebate Program are offered by:
The workshop cover residential rainwater harvesting and qualification requirements for the Rainwater Harvesting Rebate Program offered by Tucson Water.
Learning objectives:
- What is rainwater harvesting and why do it?
- Best methods to conserve potable water utilizing rainwater harvesting
- Selecting most appropriate passive and active rainwater harvesting system strategies
- Ensure implementation of rainwater harvesting best management practices (BMPs).
- Develop a rainwater harvesting project plan.
- Understand how to calculate site water supply, demand, and supplemental storage to balance onsite water budget.
- Submit application for Tucson Water’s rainwater rebate program.
Rainwater Harvesting Incentive Workshop presentation(PDF, 10MB)
Resource List for Water Harvesting(PDF, 697KB)
Project Plan
Participants are encouraged to bring a basic site plan (sketch or bird's-eye view) of their property to work on during the last hour of the class.
A project plan must be submitted with each rebate application to demonstrate the selection, use, and anticipated outcomes of the practices. The project plan may be hand drawn.
- Draw site to scale and include dimensions, property line, and street address.
- Show direction of water flow off roof tops and landscapes with arrows.
- Determine catchments.
- Identify areas that require irrigation.
- Label surface areas of hardscapes, identified rainwater practice(s), and associated potential storage volume.
Site Analysis
- Assess site conditions to determine rainwater harvesting goals.
- Use supply and demand calculations to size and locate rain tank(s).
- Use gutter and downspouts to convey the water to the storage.
- Provide retention area(s) for overflow from rain tank(s).
- Take advantage of hardscapes to catch water and redistribute to planted areas.
- Soil can serve as a catchment by grading the surface to increase and direct runoff.
- Strive for zero runoff with no rain to run off your property.
Level 1 Project Plan Example
Simple (Passive) Rain Garden
Collection – roof, patio, sidewalks
Distribution System – gutter and downspouts, channels, ditches, swales
Landscape Holding Area – concave depressions, the addition of berms, moats, or soil terracing
Step #1. Site Plan:
- Draw site to scale and include dimensions.
- Show direction of water flow off roof tops and landscapes with arrows.
- Where are the high points/ridge lines? (Indicate with a + sign.)
- Where are the low points/outlets? (Indicate with a - sign.)
- Determine catchments.
- Identify areas that require irrigation.
- Label surface areas of hardscapes and landscapes, identified rainwater practice(s), and associated potential storage volume.
Step #2. Site Analysis:
- Assess site conditions to determine rainwater harvesting goals.
- If harvesting rainwater from a roof, extend gutter/downspouts to reach planted areas or provide a path.
- Take advantage of hardscapes to catch water and redistribute to planted areas.
- Soil can also serve as a catchment by grading the surface to increase and direct runoff.
- Strive for zero runoff with no rain or irrigation water allowed to run off your property.
Step #3. Design Landscape Holding Areas:
- How can we slow the flow of water?
- Locate and size landscape holding areas.
- Locate landscape depressions that can hold water.
- Create new depressions where you want to locate plants.
- Construct berms or moats.
- Connect several holding areas with spillways or channels to distribute water throughout the site.
Level 2 Project Plan Example
Complex (Active) Rain Tank
Collection – roof
Conveyance – direct water from catchment area to storage
Storage – rain tank
Filter – gutter debris screen, downspout debris screen and filter, diverter, first flush, roof washer, etc.
Step #1. Site Analysis:
- Assess site conditions to determine rainwater harvesting goals.
- Draw site to scale and include dimensions.
- Show direction of water flow off roof tops with arrows.
- Where are the high points/ridge lines? (Indicate with a + sign.)
- Where are the low points/outlets? (Indicate with a - sign.)
- Determine catchments.
- Identify areas that require irrigation.
- Label surface areas of hardscapes and landscapes, identified rainwater practice(s), and associated potential storage volume.
Step #2. Calculations:
- Calculate the total amount of water which could be collected from roof each year and calculate the total amount of water currently needed to meet landscaping needs each year.
- Calculate site's water budget and determine whether current site conditions will meet rainwater harvesting goals.
- Calculate minimum requirement for storage (retain one-inch rainfall).
- Formula: Catchment area * 0.6 = required storage.
Step #3. Final Design:
- Use supply and demand calculations to size and locate tanks.
- Use gutters and downspouts to convey the water to the storage.
- Locate storage close to plants needing water and higher than the planted area to take advantage of gravity flow.
- Provide for distribution to all planted areas.
- Provide retention area(s) for overflow.
For more information, call Tucson Water's Public Information/Conservation Office (PICO) at 520-791-4331 or e-mail PICO.