Stormwater Storage & Treatment Facility (STF) - Inspection & Maintenance

As Bozeman grows, more roofs, driveways, and streets means more stormwater runoff. These hard surfaces do not let rain and snowmelt soak into the ground. Runoff picks up dirt, oil, trash, pet waste, and yard chemicals before flowing into local creeks. Additionally, excess runoff can cause both small and large-scale flooding. To manage this, most developments have stormwater storage and treatment facilities (STF). If you’re a property owner, POA/HOA, or property manager, you likely own and are responsible for inspecting and maintaining one or more STF.

What is a Stormwater Storage & Treatment Facility?

Stormwater STFs are engineered man-made features that store and treat stormwater runoff from hard surfaces. Common types include dry ponds or basins, grassy swales, wet-ponds, underground storage/infiltration systems, or permeable concrete pavers. They are designed to either retain or detain the excess runoff created by the addition of hard impermeable surfaces.

Stormwater Storage & Treatment Facility: Inspections & Maintenance 

Regular maintenance of STFs is crucial to ensure proper functioning. An unmaintained STF can cause flooding, property damage, and pollute local waterways. Regular maintenance also helps to avoid costly and premature major repairs.

Developing an inspection program is a critical component to successful STF maintenance. Inspections and maintenance should be completed at the following frequency:

• 1 – 3 Months: Ensure inlet and outlet pipes are not blocked by sediment, vegetation, trash, etc.
• After Large Storms: Ensure inlet and outlet pipes are not blocked by sediment, vegetation, trash, etc. Dry ponds, basins, swales, etc. should be free of standing water 48 hours after a storm event.
• Annually: Mow vegetation to 6” and remove clippings, dead plant material, and trash. Remove excess sediment, especially near inlets and outlets. Revegetate baren spots. Vacuum and flush underground storage/infiltration systems. Vacuum and clean joints of permeable pavers.
• 10 – 15 Years: Complete a professional inspection by a qualified person to ensure the STF has maintained its designed capacity. Remove excess sediment. Revegetate baren areas. Flush and vacuum underground storage/infiltration systems.

Documenting inspections and maintenance is critical to ensuring that your STF functions properly. Inspection and maintenance checklists will make sure that you collect accurate and complete information about your STFs. A records management and retention system will help keep your STFs operational as well as streamline the inspection and maintenance process.

The Stormwater Division has developed a Stormwater STF Inspections and Maintenance Guidelines to assistance property owners in developing and implementing their own programs.

By taking simple steps to care for your STFs, you are helping to reduce flooding and prevent pollution to Bozeman’s streams, rivers, and wetlands. Please contact the Stormwater Division for assistance in developing and implementing a robust STF inspection and maintenance program!!