Onsite Water Reuse Systems
Onsite Water Reuse Systems which collect rainwater, condensate water, stormwater, graywater or foundation drain water for non-potable applications such as irrigation, toilet flushing, and cooling applications are regulated under Chapter 15-13 of City Code. These types of reuse systems require a permit from Austin Water to ensure they are designed and operated in a manner that makes efficient and safe use of the water.
Which Projects are Required to Install an Onsite Water Reuse System?
Effective April 1, 2024 Onsite Water Reuse Systems are required for new commercial, multifamily and mixed-use developments with 250,000 square feet of gross floor area or more. Some projects are exempt from this requirement. Refer to the Onsite Water Reuse Program Guidebook for more info. Onsite Water Reuse Systems are also required for commercial, multi-family and mixed-use projects with new or replaced evaporative cooling towers.
The table below summarizes the alternative water sources that must be collected, and the non-potable end uses that must be provided for projects required to install and operate an Onsite Water Reuse System per City Code.
Project Size | Other Project Characteristics | Required Sources | Required Uses |
|---|---|---|---|
| 250,000 sf or greater GFA | Project has one or more commercial, multi-family, or mixed-use buildings | Combined AC condensate and Rainwater | Irrigation Toilet/urinal |
| 250,000 sf or greater GFA | Project has four or more multifamily buildings with a FAR <1 | Combined AC condensate and Rainwater | Irrigation |
| Less than 250,000 sf of GFA | Project has a cooling tower of 100 tons or greater capacity | AC condensate | Cooling tower |
GFA= Gross Floor Area FAR= Floor to Area Ratio
- Step by Step Permitting Process
Refer to the Onsite Water Reuse Program Guidebook for more info.
Site Plan Approval
Step 1. Complete a Water Balance Calculator, Meter Demand Sheet, and OWRS Site Plan Sheet for Austin Water-Onsite Water Reuse (AW-OWR) Site Plan Approval.
Step 2. Submit an OWRS Implementation Plan to AW-OWR and/or Obtain an Encroachment Agreement from Land Management (applicable only to district-scale systems and projects with components in the public right-of-way).OWRS Application Approval
Step 3. Submit an OWRS Permit Application and Engineering Report to AW-OWR– Go to the AB+C Portal to submit OWRS Permit Application.
Building Permit Approval
Step 4. Submit an Alternate Water System Permit Application to Austin Water-Utility Compliance Services Division (AW-UCSD). This application must be approved prior to Construction inspection.
Step 5. Obtain Building Permits from Development Services Department Commercial Plan Review or Expedited Building Permit Review (DSD-CPR or DSD-EBPR). OWRS Permit Application must be approved prior to Building Plan approval.Construction Inspections
Step 6. Conduct Building Construction Inspections with Development Services Department Building Inspections Division (DSD-BID)
Step 7. Conduct Cross-Connection Control Test for AW-UCSD and Final OWRS Inspection with AW-OWR
Step 8. Submit Documentation for a Permit to Operate from AW-OWROperation and Ongoing Monitoring
Step 9. Operate in Conditional Start Up Mode
Step 10. Operate in Final Use Mode with AW-OWR Approval- Project Submittal Resources
- Water Balance Calculator (version date 10/03/25)
- Meter Demand Sheet (version date 08/22/25)
- OWRS Implementation Plan
- OWRS Permit Application
- OWRS Engineering Report
- Application for Fee in Lieu of OWRS
- User Guide - Applying for OWRS Permit With the AB+C Portal
- AB+C Portal to submit OWRS Permit Application
- Resources
Technical Resources
- Onsite Water Reuse Program Guidebook
- Validated UV Reactor List
- Designers, Builders, and O&M Vendor List
- Active Registered Water Service Technicians
- Cross Connection Testing AMOC Guidance
NEW: Operations and Maintenance Resources
- December 17, 2025 – Free WateReuse webinar to introduce and discuss the OWRS O&M training manual and certificate program
- December 2025 – OWRS O&M Training Manual
- April 2026* – A finalized exam to obtain the certificate will be available to the public
- October 2026* – All OWRS permitted in the City of Austin will require treatment system managers to have the certificate
*These dates are subject to change and updates will be provided in 2026
General Resources
Additional Resources
View our webinars to learn key updates and technical guidance on implementing onsite water reuse systems in the City of Austin.
- February 28, 2024: Permitting Onsite Water Reuse Systems
- March 27, 2024: GoPurple Program Regulations and Affordability Strategies
- Onsite Water Reuse Case Studies
Austin Community College
Source: Rainwater and A/C Condensate
Use: Spray Irrigation
Treatment: TBD
Read the Case Study (PDF).jpg)
Austin Public Library
Source: Rainwater and A/C Condensate
Use: Spray Irrigation, Toilet Flushing
Treatment: Filtration, UV reactors
Read the Case Study (PDF)
Travis County Courthouse
Source: Rainwater and A/C Condensate
Use: Toilet Flushing, Irrigation, Cooling Tower Make-Up
Read the Case Study (PDF)
City of Austin Permitting & Development Center
Source: Rainwater, A/C Condensate, Blackwater, Graywater
Use: Spray Irrigation, Toilet Flushing
Treatment: Filtration, Membrane Bioreactor, UV Reactor
Read the Case Study (PDF)
- Dual Plumbing Cost Study
Dual Plumbing Cost Study (in 24 parts)
- Part 1: pages 1-15 Executive Summary and System Summary by Typology
- Part 2: pages 16-95 Conceptual Construction Cost Estimates
- Typology 1: Single Family Garden Home
- Typology 2: Single Family Ranch Home
- Typology 3: Single Family Estate Home
- Typology 4: Single Family Condo/Townhome
- Typology 5: Duplex/Side-by-Side
- Typology 6: Duplex/Stacked
- Typology 7: Multiplex/Fourplex
- Typology 8: Multiplex/Sixplex
- Typology 9: Apartment/Suburban
- Typology 10: Apartment/Mid-Rise
- Typology 11: Apartment/High-Rise Coldwater Distribution
- Typology 11: Apartment/High-Rise Graywater System
- Typology 12: Mixed Use/Ground Floor Retail-Restaurant
- Typology 13: Commercial/Hotel Mid-Rise
- Typology 14: Commercial/Hotel High-Rise
- Typology 15: Commercial/Office Mid-Rise
- Typology 16: Commercial/Office High-Rise
- Typology 17: Commercial/School
- Typology 18: Commercial/Auto Car Wash-Gas Station
- Typology 19: Commercial/Assembly
- Typology 20: Commercial/Laundry
- Typology 21: Commercial/Data Center
- Typology 22: Commercial/Civic
- Incentives for Onsite Water Reuse
To help facilitate the implementation of Onsite Water Reuse Systems, Austin Water offers several incentives as part of its GoPurple program. To learn more about the eligibility and terms of each incentive offered, please download the relevant application or file.
- OWRS Pilot Incentive Program Application – AW pays up to $1,500,000 per qualifying project
- Expedited Building Plan Review Rebate Application – AW pays up to $36,000 per qualifying project
- PACE Financing Study – AW assists applicants with documenting eligible water savings and project costs
- Contact and Program Information
Austin Water Onsite Water Reuse Program (AW-OWR)
Austin Water Utility Compliance Services Division (AW-UCSD)
- Cross Connection Control / Water Protection Program | AustinTexas.gov
- awcrossconnection@austintexas.gov
- 512-972-1060 (option #5)
Development Services Department Commercial Plan Review (DSD-CPR)
Development Services Department Expedited Building Plan Review (DSD-EBPR)
Development Services Department Building Inspections Division (DSD-BID)
Land Management