Stormwater
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Act 167
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Act 167, also known as the Pennsylvania Stormwater Management Act, was passed in 1978.  Under Act 167, counties in the Commonwealth were to develop comprehensive stormwater management plans for each watershed within the county.  The planning process is done with input from a Watershed Plan Advisory Committee (WPAC) and once approved by the Department of Environmental Protection (DEP), municipalities are required to implement the plan through local ordinances.

The practice of stormwater management has evolved as new information, technologies, and improved understanding of the relationship between human activity and the impacts of stormwater runoff have become available. In order to keep pace with the evolving practice of stormwater management, so too has the content and focus of plans produced under Act 167.

The Dauphin County Conservation District, as the county agency designated to coordinate Act 167 planning in Dauphin County, has been active in such planning since 1990. During the 1990s, several Act 167 plans were developed. During this time frame, “release rates” were the sole stormwater management standard generated by plans, and planning was done on a watershed by watershed basis. Release rates were developed using computer modeling to simulate watershed runoff in response to various size rainfall events. Release rates entail a modification of a planned retention basin to adjust the maximum rate at which stored runoff is released. Based on the timing of stream flows in a watershed, release rates were set typically between 50 and 100 percent for smaller subwatersheds within the modeled watershed. Several plans were developed under this approach, including the Paxton Creek plan, Spring Creek (West) plan and the Multi-Creek plan which covered Beaver, Manada and Bow Creeks and Kellock Run.

The first plan in Dauphin County to go beyond simple release rates was the Mid-Dauphin plan, originally approved in 2003. This plan incorporated additional management standards as Act 167 evolved to keep pace with our improved understanding of stormwater management. In addition to release rates, infiltration, water quality and channel protection standards were developed. These new standards reflected a better understanding of the effects of stormwater runoff not just from a volume perspective but from the perspective of the overall watershed hydrology, including loss of groundwater recharge and effects on water quality, stream morphology and aquatic habitat. Over the next several years, the Wiconisco Creek plan and updates to the Paxton, Spring and Multi-Creek plans incorporated the new approach. All of these plans were still being done on a watershed basis.

The Conservation District has finished a final plan for Dauphin County.  Reflecting current DEP protocol, the plan is a county wide plan and provides planning for all remaining unplanned areas and incorporates existing plans into an overall county wide plan. As Act 167 plans have now shifted from watershed by watershed planning to county-wide planning, this final plan will have the advantage of all watersheds being on the same five year update schedule.  

In incorporating existing plans into the county wide plan, the release rates for existing plans remained the same.  Release rates for Spring Creek (East), Burd and Laurel runs were developed for the 2, 10 and 25 year storms.  the 1, 50 and 100 year storm release rates were set at 100% county wide.  The table below summarizes current release rates for all watersheds in Dauphin County.

DAUPHIN COUNTY ACT 167 PLANS

RELEASE RATE REFERENCE TABLE

ORANGE SHADING – NO MODELLING DONE – NO RELEASE RATE MAP

BLUE SHADING – MODELLING DONE FOR 2, 10 AND 25 YEAR STORMS IN PREVIOUS PLANS

GREEN SHADING – MODELLING DONE FOR 2, 10 AND 25 YEAR STORMS IN THE COUNTY WIDE PLAN

ALL WATERSHEDS – 1, 50 AND 100 YEAR STORM RELEASE RATES SET AS PART OF THE COUNTY WIDE PLAN

Click on the watershed name below to view the Release Rate Map

Note: The map for Wiconisco Creek does not show realease Rates, only modeled sub areas.

Release rates for all storm events in the Wiconisco Creek Watershed are set at 100%.

Watershed Plan 1 Year Storm 2, 10, and 25 Year Strom 50 and 100 Year Storm
Mahantango Creek County Wide 100% 100% 100%
Wiconisco Creek Wiconisco 100% 100% 100%
Armstrong Creek Mid Dauphin 100% VARIES - See Plan 100%
Powells Creek Mid Dauphin 100% VARIES- See Plan 100%
Clark Creek Mid Dauphin 100% VARIES - See Plan 100%
Stony Creek Mid Dauphin 100% VARIES - See Plan 100%
Fishing Creek Mid Dauphin 100% VARIES - See Plan 100%
Paxton Creek Paxton Creek 100% VARIES - See Plan 100%
Spring Creek (West) Spring Creek 100% VARIES - See Plan 100%
Beaver Creek Multi Creek 100% VARIES - See Plan 100%
Manada Creek Multi Creek 100% VARIES - See Plan 100%
Bow Creek Multi Creek 100% VARIES - See Plan 100%
Kellock Run Multi Creek 100% VARIES - See Plan 100%
Burd Run County Wide 100% VARIES - See Plan 100%
Laurel Run County Wide 100% VARIES - See Plan 100%
Spring Creek (East) County Wide 100% VARIES - See Plan 100%
Conewago Creek County Wide 100% 100% 100%
Tributaries to Susquehanna River County Wide 100% 100% 100%
Tributaries to Swatara Creek County Wide 100% 100% 100%

The water quality and volume standards in all existing plans was replaced by the stormwater management standards found in the Pennsylvania Stormwater Best Management Practices Manual.  This brings all of Dauphin County into conformity with statewide regulations for post-construction stormwater management planning associated with NPDES permits for construction activities. The focus of new Act 167 plans, and this final plan for Dauphin County, continues to be addressing stormwater runoff from a holistic water resource perspective.

Act 167 plans are developed with input from three formed committees:

  • A Watershed Plan Advisory Committee (WPAC) comprised of municipal representatives that provides overall input for the plan.
  • A Municipal Engineers Committee (MEC) that provides technical input for the plan.
  • A Legal Advisory Committee (LAC) that provides input on ordinance requirements for the plan.

All municipalities were invited to have representation during the plan development process.  In addition, all meetings were announced to each municipality.  Each municipality also received meeting summaries throughout the process.

Dauphin County Stormwater Management Plan (Act 167)

The links below contain information from the County Wide Stormwater Managment Plan only.
Appendices and plates contain information collected for the county wide plan.
Soils and Land use maps are for Spring Creek (East), Burd Run, and Laurel Run only.

Click here for the Dauphin County Stormwater Management Plan.
Click here for the Dauphin County Model Stormwater Management Ordinance.
Click here for Appendix D Problem Areas and Obstructions.
Click here for Plate 1 - Hydrologic Soil Map.
Click here for Plate 2 - 2005 Existing Land Use Map.
Click here for Plate 3 - Full Buildout - Future Land Use Map.
Click here for Plate 4 - Laurel Run and Burd Run Watershed Release Rates Map.
Click here for Plate 5 - Spring Creek Watershed Release Rates Map.
Click here for Plate 6 - Problem Areas and Obstructions in Northern Dauphin Map.
Click here for Plate 7 - Problem Areas and Obstructions in Southern Dauphin Map.

Act 167 Stormwater Management Planning

1451 Peters Mountain Road Dauphin PA 17018 phone: 717-921-8100