Duval County LID Design Manual 2012 ENVIRONMENTAL SYMPOSIUM August 18, 2012

St Johns River Nutrient BMAP Commitments One Metric Ton Requires the City to Reduce 117.96 Metric Tons of Nitrogen to the River. Reductions need to be completed by 2023. Completed 50% reduction required by 2015. If the City does not meet allocations penalties include per FS 403.121, 403.141, 403.161: Judicial or Administrative Consent Order Fines up to $10,000 per day Growth Moratorium

Subdivision Standards Policy Advisory Committee (SSPAC) SSPAC LID Subcommittee Incorporate into Land Development Procedures Manual (Redbook) LID Manual for Duval County

LID Manual Consensus – Involve key stakeholders Guide for including LID in stormwater permitting (State and City) Voluntary – Alternative to traditional stormwater best management practices

Inadequacy of Conventional BMPs Source: Evaluation of Current Stormwater Design Criteria within the State of Florida (Harper and Baker, 2007)

Duval County LID Manual City Objectives Promote LID in the right of way LID Design Standards Sustainable Development ERP Recognition Developer acceptance Duval County LID Manual Many manuals aimed at general public Lack of permitting/crediting guidelines for stormwater designers Multiple stakeholders Aimed at Design Professionals “To complement ongoing efforts to address localized flooding and reduce the nutrient load entering surface waters, the LID Subcommittee has been tasked, by the SSPAC, with identifying and incorporating LID design criteria into the City of Jacksonville Land Development Procedures Manual (LDPM)., City Standard Specifications, and City Standard Details as appropriate.”

Starting Point

Potential Practices

Selected LID Practices Shallow Bioretention Inverted Medians Bioretention Swales Curb Extensions Pervious Pavement On-street parking Conveyance Swales

Shallow Bioretention Partial Treatment Seasonal High Water Table

Pervious Pavement Retention Credit Used for street parking / road shoulders SHWT limitation Walks and paths

Conveyance Swales SJRWMD & Draft Statewide Applicant’s Handbook Recognized volume reductions Sarasota County study - high concentration reductions Partial treatment

Conveyance Swales SJRWMD ERP Requirements Percolate either 80% or 100% of the 3-year/1-hour storm. Percolate all standing water within 72 hours. Top width-to-depth ratio of 6:1 or side slopes > 3:1. Lateral saturated infiltration must not occur.

Proposed Approach Continuous simulation using EPA-SWMM LID swale object Multiple soil types, side slopes, bottom widths, and ‘densities’ Design Aids/ Performance Charts EXAMPLE DO NOT USE

Site Evaluation and Planning Manual Outline Overview Site Evaluation and Planning LID Practices Design Examples

Practice Information Overview Design Considerations & Requirements One page table summary of practice Overview Sizing Discharge & recovery requirements Water quality / water quantity credits Design Considerations & Requirements Design steps Example calculations Standard details Design Procedure Maintenance Inspection Testing Operation and Maintenance

Project Schedule Jan 2012 – Report Initial Findings Mar 2012 – Proposed LID Practices May 2012 – Revisions to Proposed LID Practices Jul 2012 – Draft LID Manual Review Meeting 1 Sep 2012 – Draft LID Manual Review Meeting 2 Nov 2012 – Draft LID Manual Review Meeting 3 Jan 2013 – Presentation to Full SSPAC

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SSPAC / LID Subcommittee Acknowledgements Jones Edmunds CDM-Smith R-A-M Professional Group Dr. Marty Wanielista Consultant Team You? SSPAC / LID Subcommittee

Questions