Why is Storm Water a Problem?

1. Stormwater, Floodplain and WetlandsNewly Elected Officials CourseJanuary 28, 2006Andrew W. Blenko, P.E., J.D.

2. Why is Storm Water a Problem? Increased runoff due to development (quantity and flooding)

3. Why is Storm Water a Problem? Development = Impervious Surfaces = Increased Runoff = Flooding

4. Why is Storm Water a Problem? Damage to your infrastructure: Damage to your residents:

5. Why is Storm Water a Problem? Pollution from contaminants

6. Why is Storm Water a Problem? Pollution from illicit discharges

7. Why is Storm Water a Problem? Erosion and Sedimentation

8. Why is Storm Water a Problem? Reduced Groundwater Recharge

9. Why is Storm Water a Problem? Reduced Groundwater Recharge

10. Act 167 of 1978Pa. Stormwater Management Act Persons who develop land must: • Assure the maximum rate of runoff is no greater after development than before OR; • Manage quantity, velocity and direction of resulting storm water runoff in a manner which otherwise adequately protects health and property from possible injury.

11. Reading a Stream Hydrograph A hydrograph presents a picture of what is happeningto the volume of water in a stream during and after a rainfall event.

12. Development increases the Amount of Runoff and Decreases Infiltration

13. Development Increases the Velocity (Rate) of Runoff

14. Development increases the Peak Flow Rate and decreases the Travel Time

15. Traditional Approach has been to Detain Runoff so Peak Rate of Runoff is Maintained

16. Traditional Approach has been to Detain Runoff so Peak Rate of Runoff is Maintained

17. New Approach Looks at Reducing Runoff Volume and Maintaining Quality of Stormwater Runoff

18. What is a Watershed? • A contiguous land area that drains to a common point • A Geographic Boundary, not a Political Unit • Encompasses all water systems • Storm Water • Sanitary • Water Supply

19. Watershed Characteristics: • Slopes • Vegetation • Land Cover • Forest • Meadows • Pavement • Floodplains • Wetlands • Hydrology • Soils • Land Use • Agriculture • Residential • Industrial • Open

20. Many Municipalities are Living with Recurring Problems due to Poor Stormwater Management in the Past – Solutions must involve all communities in a watershed since the problems cross municipal boundaries.

21. Maintain Stream Capacity

22. Stormwater Management Philosophy Comprehensive • Based on a Plan • Preventative • Multi-Purpose • Volume and Rate Control Oriented • Traditional • Remedial • Site Oriented • Conveyance Oriented • Single Purpose • Piecemeal

23. Alternative Management Techniques Municipal and Regional Planning • Comprehensive Planning • Open/Green Space • “Stormwater Space” • Acknowledge Act 167 SMPs in Plans • Regional Stormwater Facilities • Zoning and Ordinances • Long-Term Property Buy-Out Plans in Floodplains • Law Suits over Upstream Stormwater Management Practices

24. Making Up for Past Sins: Penn Township, Westmoreland County Berlin Road Dam • Built to alleviate flooding of approximately 20 homes, (including first floor flooding of 5 homes) • Phase I included elliptical drainage pipes and wetland mitigation; construction costs were $238,000 • Phase 2 included a 5-acre detention facility to control stormwater from approximately 100 upstream acres • Total Phase 2 construction cost of $451,000 • One of the first stormwater projects funded by PennVest • Completed in 2002

25. Making Up for Past Sins: Penn Township, Westmoreland County Cortina Marie Detention Pond • Resulted from a law suit by 9 property owners repeatedly flooded • Township purchased 5 acres of prime real estate for $404,000 • Total project cost including land acquisition, engineering, and permitting - $1.14 million • Funded with a PennVest loan • Completed in 2003

26. Making Up for Past Sins: Kennedy Township, Allegheny County Pine Hollow Detention Basin • Protects the Township of Stowe and the Borough of McKees Rocks • Constructed 1998-99 • Cost $237,000 • Financed by the Allegheny County Authority for Improvements in Municipalities • 5-year term • All costs born by the Township of Kennedy

27. Good Stormwater Management Saves Money!!! We Need to be Creative and Think Outside the Box

28. Stormwater Phase II Program (Cities with <100,000 Population) • MS4 – Municipal Separate Storm Sewer System • Storm Sewer Discharges must be Permitted in Urban Areas • Requires General or Individual Permit from PADEP

29. Stormwater Phase II Program Six Minimum Controls: • Public Education and Outreach • Public Participation and Involvement • Illicit Discharge Detection and Elimination • Construction Site Runoff • Post-Construction Runoff • Pollution Prevention/Good Housekeeping

30. Stormwater Phase II Program Public Education, Participation & Outreach

31. Stormwater Phase II Program Illicit Discharge Detection and Elimination

32. Stormwater Phase II Program Post-Construction Runoff Controls

33. Stormwater Phase II Program Municipal Good Housekeeping

34. Wetlands • Rule One: Avoid Them! • Wetland issues are regulated jointly by PADEP and the USACOE • Wetlands are Beneficial • Even a small disturbance requires regulatory review

35. Floodplains • 100 and 500-Year Floodplains delineated by FEMA in Flood Insurance Rate Study Maps • Original maps in our area done in late 1970s • Generally Updated every ten years

36. Floodplains LOMR – Letter of Map Revison LOMA – Letter of Map Amendment • Issued by FEMA as a result of Changed Condition • Requires a HEC-RAS or other hydraulic study to Justify

37. Floodplains Floodway – cross section needed to convey runoff from design storms Floodplain – Areas inundated with water during design storms Never build in Floodway; Okay to build in Floodplain as long as first floor is above flood elevation and structure designed to withstand flooding

38. Questions? Thank you for your interest in serving your communities and making them a better place to live and work!