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City of Clarksville Storm Water Management Manual Revisions 2014.

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Presentation on theme: "City of Clarksville Storm Water Management Manual Revisions 2014."— Presentation transcript:

1 City of Clarksville Storm Water Management Manual Revisions 2014

2  U.S. Environmental Protection Agency (EPA)  State of Tennessee Department of Environment and Conservation (TDEC)  National Pollutant Discharge Elimination System (NPDES)  Municipal Separate Storm Sewer System (MS4) Permit  Construction General Permit Why?

3  Objective  Manage storm water  Minimize pollution  Initially issued June 2003  Current coverage issued March 10, 2011  Expires September 1, 2015  48 months to implement regulatory revisions  Permanent stormwater management/green infrastructure BMP’s City of Clarksville MS4 Permit

4  Engineers  Developers  Builders – Appendix N  Contractors  Vendors  Concrete  Material Deliveries Who will be affected?

5  4.2 Digital Submittals  Removal of old information to reflect current technology  4.7 New Development Plans Review and Permitting Processing  Preconstruction Meeting Requirements  Notice of Coverage for state /federal permits (if applicable)  General Contractor Construction Schedule  4.8 Construction Procedures  Permit time limits  2 years  6 months of inactivity beyond 2 years requires resubmittal  No Extensions Manual Revisions Chapter 4

6  5.2 Buffer Widths and Zones  Now reflects current TDEC requirements  For streams-changed from 50 feet to 60 feet  For other waterbodies-changed from 20 feet to 30 feet Manual Revisions Chapter 5

7  Technical Guidelines and Criteria  References Metro Nashville’s Stormwater Management Manual Volume 2 throughout chapter  24 hour 100 year storm event changed from 6.78 inches to 7.61 inches - NOAA  Revision based on best available technical data Manual Revisions Chapter 7

8  City of Clarksville’s Erosion Prevention Sediment Control Program based on the most current TDEC Erosion and Sediment Control Handbook  8.2 Inlet Protection-added approved devices  Manufactured Devices  Excavation around perimeter of drop inlet  Erosion eels, socks, and wattles  Gravel bags and sand bags  Block and gravel protection  Filter fabric wrapping prohibited Manual Revisions Chapter 8

9  Manufactured Devices Chapter 8 Inlet Protection-Approved Devices

10  Excavation around perimeter of drop inlet Chapter 8 Inlet Protection-Approved Devices Gravel – supported by filter fabric to allow drainage and restrict sediment movement.

11  Dikes, erosion eels, socks, and wattles Chapter 8 Inlet Protection-Approved Devices

12  Gravel Bags and Sand Bags Chapter 8 Inlet Protection-Approved Devices

13  Gravel Bags and Sand Bags Chapter 8 Inlet Protection-Approved Devices

14  Block and Gravel Protection Chapter 8 Inlet Protection-Approved Devices Filte r Fabr ic

15  Filter Fabric - Prohibited  Wrapping or placement of filter fabric on top of inlets/grates is prohibited.  Requires more frequent maintenance  Lack of maintenance causes  Ponding/flooding  Excessive sediment  Often removed, punctured or bypassed Chapter 8 Inlet Protection

16 Maintenance and installation problems

17

18  9.1 Introduction to Storm Quality  Low Impact Development (LID) criteria added  Utilizes a system of source controls and small scale, decentralized treatment practices to help maintain the hydrologic function of the landscape by allowing water to infiltrate, evapotranspirate, or be reused onsite.  Effective March 10, 2015  Metro Nashville’s Volume 5 Low Impact Development Stormwater Management Manual accepted methodology Manual Revisions Chapter 9

19  9.3.1 Storm Water Credits Manual Revisions Chapter 9

20  9.12 Catch Basin Inserts  Description, criteria, and calculation updated  Limited to 1 acre or less of impervious area  Each insert limited to 1/3 acre drainage basin  Q=C*I*A  I = 2.45 inches/hour Manual Revisions Chapter 9

21  9.12 Catch Basin Inserts Example

22 Manual Revisions Chapter 9  9.12 Catch Basin Insert Example

23  9.13 Permeable Pavements  Description and criteria added Manual Revisions Chapter 9

24  Now reflects current TDEC requirements  10.1.1 Zones  For streams - changed from 50 feet to 60 feet  For wetlands and other waterbodies - changed from 20 feet to 30 feet  10.1.2 Buffer Width and Averaging  May average the 60 feet criterion  Minimum width must be 30 feet at any location  10.1.3 Level Spreaders  Riprap shall not be used in level spreader designs Chapter 10 Water Quality Buffer Design

25 Appendix N Small Lot Erosion Control Building permit application now requires TDEC permit number EROSION PREVENTION & SEDIMENT CONTROL (EPSC) PLAN FOR SMALL LOTS DISTURBING <1 ACRE A building permit WILL NOT BE ISSUED until this form is filled out completely.

26 Appendix N Small Lot Erosion Control OptionABCDEFG Lot #(s) EPSC plan options for Building Permits- Choose one or a combination of the lettered schematics to represent measures used on lots. Identify lot #’s and corresponding option(s).  Construction entrance shall have 1.5-3.5 inch stone at 6 inches depth

27 Questions?


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