STORMWATER MANAGEMENT DAUPHIN COUNTY CONSERVATION DISTRICT Bob Christoff

STORMWATER MANAGEMENT DAUPHIN COUNTY CONSERVATION DISTRICT Bob Christoff 717 -921 -8100 rchristoff@dauphinc. org

WHY MANAGE STORMWATER? At one point, stormwater management was simply collect and dump. Stormwater was a nuisance. Next came detention ponds designed to slow the release of stormwater to local streams. The problem with these approaches is that they failed to consider stormwater as a resource and failed to consider the range of impacts related to improper stormwater management. - Increased volumes of runoff to local streams - Channel erosion - Pollutants carried with stormwater - Increased local flooding - In stream habitat degradation - Loss of groundwater recharge and base flow - Clogged culverts - Undercut roads - Increased infrastructure and public expense

SOURCE: Maine Volunteer Lake Monitoring Program Website SOURCE: CARTERET COUNTY HOMEBUILDERS ASSOCIATION

SOURCE: CENTER FOR WATERSHED PROTECTION

SOURCE: www. planningwithpower. org/pubs/id-257. htm RESEARCH INDICATES THAT STREAMS BEGIN TO BE IMPACTED WHEN THE WATERSHED REACHES ABOUT 10% IMPERVIOUS COVER. AT ABOUT 25% IMPERVIOUS COVER THE STREAM BECOMES DEGRADED.

EFFECT OF INCREASED RUNOFF ON FLOOD LEVELS SOURCE: www. dec. ny. gov/docs/water_pdf/swdmch 2 part 2. pdf THE ILLUSTRATION ABOVE SHOWS THE EFFECT OF INCREASED RUNOFF ON FLOOD LEVELS. ALSO NOTE THE DECREASED DRY WEATHER FLOW.

SOMETHING TO THINK ABOUT MANY OF THESE SLIDES SHOW THE DIFFERENCES BETWEEN “DEVELOPED” AND “UNDEVELOPED” CONDITIONS AND UNDERSCORE THE ADVERSE IMPACTS OF “DEVELOPMENT”. MUCH OF THIS INFORMATION IS BASED ON HISTORIC DEVELOPMENT. HISTORICALLY, WE HAVE NOT DONE A GOOD JOB MANAGING STORMWATER FROM DEVELOPMENT. WE CAN DEVELOP AND DO A BETTER JOB OF MANAGING STORMWATER.

HAVING LEARNED MUCH ABOUT THE IMPACTS OF POOR STORMWATER MANAGEMENT, WE NOW TRY TO MANAGE STORMWATER AS A PART OF OUR WATER RESOURCES Current stormwater management considers: - Volume of runoff - Rate of runoff - Quality of runoff - Impacts on physical, chemical and biological health of the stream - Loss of groundwater RAIN GARDEN PHOTO COURTESY OF LINCOLN, NEBRASKA, WATERSHED MANAGEMENT DIVISION

REGULATIONS FEDERAL REGULATIONS (EPA) NPDES Construction Permits NPDES Post Construction SWM Requirements NPDES Municipal Separate Storm Sewer System (MS 4) Permits STATE REGULATIONS (DEP) Erosion and Sediment Pollution Control (Chapter 102) Post Construction SWM Requirements (Chapter 102) Act 167 Stormwater Management Planning MS 4 Permitting LOCAL ORDINANCES Stormwater Management Erosion and Sediment Pollution Control Illicit Discharges WHO IS INVOLVED EPA, DEP, Conservation Districts, Municipal Governments THE FOLLOWING DIAGRAM WILL MAKE EVERYTHING CRYSTAL CLEAR

EPA DEP NPDES MS 4 PERMITTING ACT 167 CONSTRUCTION PERMITTING TMDLS POST CONSTRUCTION SWM CHAPTER 102 DCCD LOCAL ORDINANCES MUNICIPALITIES

SUMMARY -Land use changes result in changes in runoff peak discharges, volume and quality. In Pennsylvania, land use decisions are primarily in the hands of local governments. -Increased runoff contributes to channel and habitat degradation, reduced water quality, reduced baseflow, localized flooding and increased public cost for maintenance, repair and replacement. -Development itself is not the cause. Development that fails to consider and manage the adverse impacts of increased runoff is the problem. -Most of our stormwater problems today are the result of decades of this failure. -Regulatory requirements and increasing problems are forcing better management and remediation of existing problems.

BETTER DEVELOPMENT Every development site is different (soils, slope, geology, existing land cover, drainage patterns and features) The specific approach to sound stormwater management will differ by site To effectively manage stormwater we must: Work with the existing features, limitations and opportunities of each site Recognize and understand that we may not be able to force some development into certain sites Provide flexible local regulations that provide development with the ability to achieve sound stormwater management Effective use of Best Management Practices (BMPs)

BMPs -Best Management Practices (BMPs) are practices employed to manage stormwater. -BMPs can be structural (installed practices) or non structural (site design, ordinance requirements) Structural: Infiltration beds Bioretentian areas Rain gardens detention/retention ponds Non Structural: Protect sensitive areas (steep slopes, wetlands, riparian areas) Reduce impervious areas Use natural flow paths Planning and regulations -By using planning and design approaches that consider and employ non structural BMPs the need for structural BMPs can be minimized.

WHERE ARE WE NOW? Many municipalities are struggling with stormwater problems that are the result of decades of improper management. - Stream and habitat degradation - Increased localized flooding - Infrastructure repair and replacement - Citizen complaints and pressure to “fix it” Increasing state and federal regulations are placing an additional burden on local governments. - NPDES MS 4 Permitting (including PCSM responsibilities) - Total Maximum Daily Loads (TMDLs) - Chesapeake Bay Pollutant Reductions Municipal Governments are being asked (required) to address existing water quality problems under MS 4 permits. Long term operation and maintenance of SWM BMPs Developers have increasing regulatory requirements for SWM quantity and quality. Continued pressure and adverse impact on water resources. Increasing public and private expense related to stormwater management and problems.

WHERE DO WE GO FROM HERE? Some municipalities are considering a stormwater fee to fund needed improvements and to meet regulatory requirements. Sound management now can help to prevent future problems and stabilize existing problems. Incorporate consideration for the impact of land use and development into the development of planning mechanisms (Comprehensive plan, SALDO, Zoning, Floodplain, SWM ordinances) Incorporate flexibilty and Low Impact Development principles into local ordinances such as zoning and subdivision and land development ordinances Protect and reestablishing critical areas such as stream buffers and floodplains Minimize development site disturbance (leave existing vegetation in tact, maintain or enhance riparian buffers, do not compact or remove soils)

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