Post-Construction Process for Long-Term BMP Maintenance

bioswaleStormwater best management practices (BMPs) are designed to meet water quality and quantity standards and are crucial in preventing flooding and stormwater pollution in our community. Under the State's NPDES stormwater permit, the Town of Mount Pleasant is required to ensure that any stormwater best management practices (BMP) installed within the Town are properly maintained by the owner of the BMP. This applies to all privately and publicly owned BMPs within the Town's jurisdiction. 

New Projects -

As-built Checklist


As-builts are required for new projects to allow project engineers to review the built condition and confirm/ certify that the project was built according to their plans. The information is also used to manage the post-construction BMPs and infrastructure. DRAFT as-built submittal should be made well in advance of project closeout to allow for review, comment, and corrections. To expedite your process and approval, please follow the as-built checklist and submit the checklist form with your documents. Access the as-built checklist here. 

Existing Systems - Long Term Inspections and Maintenance

Systems Built Prior to 2007

Owners of previously existing systems are also required to maintain their BMPs in a functional condition.   Systems built between 1992 and 2007 have agreements for maintenance on file with SCDHEC.  Be aware - not all ponds were created to function exactly like modern systems, however, they still need maintenance like new systems in order to provide flood and water quality benefits.  We recommend utilizing the provided inspection forms for evaluating these systems.

Systems built after September 1, 2007

All new projects that are reviewed and approved by the Town and are installing stormwater BMPs must submit a maintenance agreement to the Town. This agreement requires the site owner to inspect and maintain their BMPs to ensure optimal performance. Annual inspections of the system, detailing any maintenance required or undertaken, must be performed by a qualified engineer and reports sent to the Town.

**New November 2021 - The town will accept annual inspection reports from certified BMP Inspectors.
The Town will perform random site inspections to ensure owners are taking proper care of their systems. Maintenance required for each system will be dependent on the type of BMP implemented at your site.

Please send your annual inspection reports to:
Stormwater-Water Quality Division
Town of Mount Pleasant
Attn: NPDES Coordinator
100 Ann Edwards Lane
Mount Pleasant, SC 29464
Fax: 843-849-2760

 Stormwater Best Management Practices (BMPs) and Inspection Forms

1. Fill out an Annual Report Form for each property.
2. Complete one inspection checklist form each system (i.e. one form for each pond on the property)
 Practice  Inspection Form Practice Description 
Wet Pond  Wet Pond Checklist  A Wet pond is a stormwater pond that has a "permanent pool" of water.  The area below the water is for capturing and storing pollution.  The area from the water level to the top of the pond bank is the flood water storage area.
Dry Pond  Dry Pond Checklist  A dry pond is a system that captures stormwater during rain events.  Generally the area is dry in between rain events.  The flood water storage area is from the bottom of the pond area to the top of bank.
Bioretention  Bioretention Checklist A bioretention system is similar to a dry pond.  The system utilizes special soils, turf, or mulch and plants to hold water temporarily during and after rain events.  Plants help to absorb pollution and flood waters.   
Underground Detention  Underground Detention Checklist Underground detention systems are engineered underground stormwater storage systems located under parking lots.  These system function like a pond.  The system can infiltrate flood waters into the ground or provide storage until the pond area can drain down. 
Manufactured Treatment Device  Manufactured Treatment Device Checklist A Manufactured treatment device may also be known as a filter system, oil/ water separator, or Type 1 MTD.  These systems screen out (capture) and treat different types of pollution.  They are often used in road projects, areas that do not require ponds for flood storage, or as pre-treatment for ponds and underground systems.
Grass Swale  Grass Swale Checklist  A grass swale is a shallow grassed ditch system that slows down water and utilizes grass to "filter" sediment (a pollutant) from the stormwater. 
Pervious Pavement  *  Pervious pavement are road and parking systems that allow water to filter through the surface and allow water to soak into the ground.  These system reduce the amount of stormwater or change how quickly the water flows off of a property.  Systems can include paver stones, porous concrete, porous asphalt, grassed systems, and gravel systems.  They are generally more engineered than just gravel or dirt areas.
Constructed Wetland  Constructed Wetland Checklist A constructed wetland is similar to a wet pond.  It will have dry and wet areas that are planted to mimic a natural wetland but they have been designed to capture pollution, manage flood waters, and require maintenance and cleaning over time. 
Level Spreader  Level Spreader Checklist  A level spreader is a system that spreads runoff over a wider area and through a grass or other filter system to slow water down and allow sediment to collect.
Sand Filter  Sand Filter Checklist  A sand filter is a system that uses a sand pit to capture flood waters and pollution.  This allows the water to slowly filter through the sand.
Infiltration Trench  * An underground trench that is filled with gravel and wrapped in a geo-fabric to provide a place for water to collect and soak into the ground.
Green Roof  * A green roof is a planted system installed on a roof that helps to capture rain water and slow down the run-off.  It utilizes special plants to help soak up and use the rain water. 
Rain barrels/ Cisterns  * Rain barrels (small roof capture systems) and cisterns (larger roof/ water capture systems) collect rain water from roof areas and hold the water for future re-use (in irrigation systems or plumbing systems).
Other  * Over time and with innovation new treatment systems and flood control systems are being discovered and developed. 

* systems with no form provided are in development. 

**Inspection Checklists are developed to provide a general review of system components.  Individual systems may have special components or inspection and maintenance requirements that may need to be researched or evaluated.  Utilizing an inspecting professional can help identify site specific needs.

  Many other resources are available to help BMP owners properly maintain or evaluate their sites,

Adding items to our around your pond?   Consider the following:

  • You may need a Drainage Easement Encroachment Permit - we can help you check 
  • Fountains and Aerators may also need other permits - review the Pond Fountain checklist
  • Keep structures, trees, and vegetation away from pond access areas and pipes - these areas need to be open for future maintenance activities.