Workshop and Project Plans

Tucson Water workshop

Free workshops for the Rainwater Harvesting Rebate Program are offered by:

The three-hour workshop covers residential rainwater harvesting and qualification requirements for the Rainwater Harvesting Rebate Program offered by Tucson Water.

Learning objectives:

  1. What is rainwater harvesting and why do it?
  2. Best methods to conserve potable water utilizing rainwater harvesting
  3. Selecting most appropriate passive and active rainwater harvesting system strategies
  4. Ensure implementation of rainwater harvesting best management practices (BMPs).
  5. Develop a rainwater harvesting project plan.
  6. Understand how to calculate site water supply, demand, and supplemental storage to balance onsite water budget.
  7. Submit application for Tucson Water’s rainwater rebate program.

Rainwater Harvesting and Gray Water Reuse Resources (936 KB)

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.

Tucson Water workshop level 1 exampleLevel 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.

Tucson Water workshop level 2 exampleLevel 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.