An infiltration trenches (also called infiltration areas) is a small trench filled with stone that collects rainwater from paved surfaces such as driveways and allows it to absorb into the surrounding soil. An infiltration area receives rainwater from surface runoff, not underground pipes like a buried dry well.
Infiltration trenches are common on residential lots, where they are typically located next to driveways and at least 20 feet from a building. Their location can be identified by the stone at the surface. Infiltration trenches are often found with sand filters.
Maintaining Infiltration Trenches
As the property owner, you are responsible for all maintenance of your infiltration trench unless a shared maintenance agreement has been made with the DEP Stormwater Facility Maintenance Program.
Infiltration trenches need simple maintenance to keep stormwater flowing into them, such as the removal of sediment, leaves and plant debris from the trench and flow paths.
An un-maintained infiltration trench may:
By maintaining your infiltration trench, you are doing your part to help the environment and protect your local streams and the Chesapeake Bay.
DEP can answer your questions and provide additional guidance about maintaining your stormwater facility. Please email firstname.lastname@example.org or call the Montgomery County Customer Service Center at 3-1-1.
Infiltration Trenches in the Stormwater Facilities Maintenance Program
The Stormwater Facilities Maintenance Program is responsible for maintaining all public stormwater facilities as well as all private facilities that transferred their maintenance to the County. The program also maintains facilities that were required as part of the Department of Planning permits.
Can I remove my Infiltration Trench after installation?
No, you cannot remove any facilities that were part of your building installation - these are permitted structures and DEP maintains a database of these facility locations as part of the Stormwater Facility Maintenance Program. DEP may perform a maintenance inspection of your practice if it is a permitted structure. Property owners must contact DEP before any major changes can be performed to the structure.
Resources and Financial Incentives
Have a infiltration trench on your property? Financial incentives are available for you.
The Water Quality Protection Charge Credit Program
After you have installed your infiltration trench, you are now eligible to receive a credit off your annual Water Quality Protection Charge (found on your yearly property tax bill). The credit provides an incentive for maintaining your infiltration trench and other stormwater management practices.
You must apply for the WQPC credit separately – the credit will not be provided to you automatically.
Residential property owners can receive up to 50% off their WQPC depending on the type and size of stormwater management practices on the property.
Non-residential and multi-family properties can receive up to 50-60% off their WQPC depending on the type and size of the stormwater management practices on the property.