City of Tempe, AZ
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Post construction program
The stormwater post-construction program evaluates new and redevelopment projects. To ensure compliance with the Arizona Department of Environmental Quality’s (ADEQ) Arizona Pollutant Discharge Elimination System, the City of Tempe evaluates all new development and redevelopment projects based on the following criteria:
- Project is one acre or greater in size
- Construction application was submitted or after Aug. 1, 2023
- Project contains permanent post-construction controls (e.g., detention basin, dry well, green infrastructure)
- Stormwater will discharge or has the potential to discharge to the Municipal Separate Storm Sewer System (MS4)
A summary of requirements follows.
Inspections
Applicable projects will undergo a stormwater site warranty inspection from Tempe staff within one year after construction completion. Additional inspections will be required by the owner or the owner’s representative to confirm controls are in accordance with the City of Tempe Engineering Design Criteria.
Maintenance
It will be the responsibility of the property owner to provide adequate long-term maintenance of the stormwater control measures and drainage infrastructure to ensure that these measures remain in proper working condition in accordance with approved as-builts, rules and regulations and applicable laws.
Maintenance requirements under the current City of Tempe Stormwater Management Plan and Engineering Design Criteria and applicable Tempe City Code Chapter 12 remain in effect.
This program is still in development as to how maintenance will be demonstrated. Updates will be posted to this site as they become available.
- Tempe City Code
- Engineering Design Criteria
- Stormwater Management Plan
- Enforcement Response Plan
Drainage infrastructure maintenance guidelines
The required maintenance interval for the drainage infrastructure is dependent upon the degree of pollutant loading from a particular drainage basin. Though each drainage infrastructure type has its own unique characteristics, inspections generally will consist of an assessment to assure functionality to design capacity and the general condition.
Inspections should be performed following a rain event to ensure 36-hour water dissipation. Routine maintenance should consist of trash and vegetation removal, unclogging of drains, minor sediment removal and exchange of filter media where applicable.
Major maintenance, such as dredging, excavating, removing existing media, replacing fabric, replacing the under‐drain and reestablishing vegetation, will be completed as required from inspections and would consist of reconstruction resulting from failures in the infrastructure.
Routine infrastructure maintenance will help avoid more costly rehabilitative maintenance. Optimum maintenance frequency is met when routine maintenance is performed more frequently than inspection intervals. Infrastructure is considered to be operating at reduced capacity when maintenance thresholds are exceeded by the time the infrastructure is inspected.
The following schedule is offered as a guideline for performing inspections and routine maintenance for a range of infrastructure.
|
Drainage Infrastructure |
Routine Inspection and Maintenance Frequency* |
Inspection Record Submittal (or sooner upon request) |
|
Bioretention System |
2 per year |
Once every 5 years |
|
Bubbler Boxes |
1 per year |
Once every 5 years |
|
Cartridge or Module Media Filtration Structures |
1–2 per year |
Once every 5 years |
|
Catch Basins/Trenches/Slotted Drain |
1 per year |
Once every 5 years |
|
Catch Basin Inserts (long term) |
3–4 per year |
Once every 5 years |
|
Channels |
1 per year |
Once every 5 years |
|
Conduits/Culverts |
1 per year |
Once every 5 years |
|
Detention/Retention Ponds/Basins |
1 per year |
Once every 5 years |
|
Dry Pond |
1 per year |
Once every 5 years |
|
Dry Wells |
1 per year |
Once every 5 years |
|
Ditches |
1 per year |
Once every 5 years |
|
Filter Strips or Swales |
3-4 per year |
Once every 5 years |
|
Infiltration Trenches |
3-4 per year |
Once every 5 years |
|
Permeable Pavement |
1 per year |
Once every 5 years |
|
Rainwater Gardens |
2–3 per year |
Once every 5 years |
|
Rainwater Harvesting |
2–3 per year |
Once every 5 years |
|
Sand Filter |
1–2 per year |
Once every 5 years |
|
Scupper |
1 per year |
Once every 5 years |
|
Trash & Debris Screens |
3–4 per year |
Once every 5 years |
|
Underground Storage Facilities |
1 per year |
Once every 5 years |
|
*Perform inspections within 36 hours of a rain event |
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