Maintaining Your Detention Basin

A Guidebook for Private Owners in Cranberry Township

Detention Pond Inspection
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Detention (Dry) and retention (Wet) basins are a storm water Best Management Practice (BMP) designed to reduce the impacts of pollutants and increased storm water on local streams caused by development.

Retention ponds are stormwater basins that include a permanent pool for water quality treatment and additional capacity above the permanent pool for temporary storage. A dry detention basin is an earthen structure that provides temporary storage of runoff and functions hydraulically to attenuate stormwater runoff peaks.

The basins are designed to control runoff peak flow rates of discharge for the 1 year through the 100 year events.
The Pennsylvania Department of Environmental Protection (PA-DEP) has mandated that every municipality inspect all detention and retention ponds annually. Cranberry Township wants to inform the homeowners how to properly maintain your ponds. Your stormwater detention and/or retention pond is an essential part of Pennsylvania’s efforts to improve the water quality of our streams, rivers, and lakes. 

Stormwater Management History

Before 2002, rainwater runoff issues were addressed separately for each new development in Cranberry. However, as the surface contours of the Township continued changing with new development, the need for a coordinated, global, and comprehensive approach to handling storm water became apparent. In 2002, Cranberry implemented a plan to deal with flooding, infiltration/inflow problems, detention, and related stormwater drainage concerns.

That stormwater management plan targets the accelerated runoff resulting from land development and prescribes the construction of various swales, culverts, catch basins and detention ponds, as well as other water-handling facilities to channel and stage the release of rainwater to prevent downstream flooding.

Detention Pond Maintenance Responsibility


Responsibility varies throughout the Township, but if your homeowner's association (HOA) or business owns the property where the pond is located and subject to a maintenance agreement, most likely you are the responsible party. If you are unsure, contact the Township.

Detention Pond Maintenance & Responsibilities

A consistent maintenance program is the best way to ensure that a detention basin will continue to perform its water quality and flood control functions. The first step in a maintenance program is to obtain a copy of the stormwater facility plans from either the Butler County Courthouse Recorder of Deeds or the Township Engineering Department, to determine how your basin was designed to function. 

The responsibility for maintaining these stormwater facilities is divided among homeowners, neighborhood associations, commercial property owners, the Township, and state authorities as follows: 

  • Roof and foundation drains These drains, along with the gutters, spouts and pipes which connect them to the community’s storm sewer system, are the homeowner’s responsibility.
  • Driveway pipes and culverts These are typically the homeowner’s responsibility.
  • Drainage ditches These are generally the responsibility of the homeowners association unless the ditch is specifically designated as a public or municipal drainage easement.
  • Pipes and culverts underneath roadways The owner of the road assumes responsibility for these facilities. On private roads, or on newer plans where the roads have not yet been accepted by the Township, it is the homeowners’ or developer’s responsibility. On public roads, it is the responsibility of either the Township or the State.    
  • Clearing debris and erosion along stream channels Removing debris from local streams to keep them flowing in their channels is generally the responsibility of the land owners whose property abuts or is traversed by that stream. Note, however, that repair of erosion on large streams, such as building channel walls, may require a state permit.
  • Catch basins The owner of the road along which catch basins are situated is responsible for maintaining them. That could be either the Township, PennDOT, the plan developer, or the owners of a private roadway or parking lot where basins are installed.
  • Detention facilities Detention ponds in residential plans are typically the responsibility of the neighborhood’s homeowners association. Detention facilities in non-residential areas are normally the responsibility of the private establishments they serve. Developers are typically responsible for detention pond maintenance in newly developing plans until they are turned over to the homeowners association.