1. Putting the “LID” on Water Pollution New Water Quality Requirements for Land Use County of Orange Mary Anne Skorpanich Richard Boon

2. Overview 1.Introduction 2.Key Terms 3.Regulatory Framework 4.WQMP Process 5.Schedule 6.Questions

3. Urban Runoff Effects There are four interrelated but separable effects of land-use changes on the hydrology of an area: changes in peak flow characteristics, changes in total runoff, changes in quality of water, and changes in the hydrologic amenities. --Luna Leopold, 1968

4. Low Impact Development: LID The low-impact development “functional landscape” emulates the predevelopment temporary storage (detention) and infiltration (retention) functions of the site. This functional landscape is designed to mimic the predevelopment hydrologic conditions through runoff volume control, peak runoff rate control, flow frequency/duration control, and water quality control. --Low Impact Development Hydrologic Analysis, The Prince George’s County DER, 1999. p.11

5. Water Quality Management Plan A project submittal that describes the Best Management Practices that will be implemented and maintained throughout the life of a project. Conceptual and/or Preliminary WQMPs Final Project WQMPs

6. Municipal Stormwater Permits Require County, OCFCD and cities to: Effectively prohibit non-stormwater discharges into the municipal drainage system Implement controls on stormwater pollution to the maximum extent practicable Prescribes a management program Drainage Area Management Plan Section 7.0 - Land Development Renewed in 1990, 1996, 2002, 2009

7. 2009 Stormwater Permits: Land Development Santa Ana RegionSan Diego Region LID: On- or off-site 85th percentile storm volume capture for LID and water quality LID: On-site 85th percentile storm volume capture for LID and water quality Hydromodification: 2 year storm volume capture for discharges to susceptible channels Hydromodification: (0.1)2 year-10 year storm volume hydrograph matching

8. Land Development Program Revamp 2003 Stormwater Permits Priority Projects must treat the design storm runoff volume 2009 Stormwater Permits Priority Projects must retain the design storm runoff volume using LID and/or participate in alternative compliance mechanisms Priority Projects must address hydromodification

9. Consultation Process Permittee Advisory Group, PAG Technical Advisory Group, TAG Building industry representatives, OCBC Engineering, geotechnical, and landscape architecture professional associations Water and wastewater agencies OC Coastkeeper, Natural Resources Defense Council Federal and state regulators Meetings held October 2009 - 2011

10. Priority Projects (I) New development projects that create 10,000 ft 2 or more of impervious surface Automotive repair shops Restaurants where the land area of development is 5,000 ft 2 or more, including parking area Hillside developments of 5,000 ft 2 or more Parking lots of 5,000 ft 2 or more

11. Priority Projects (II) Impervious surface of 2,500 ft 2 or more located within, directly adjacent to, or discharging directly into receiving waters within Environmentally Sensitive Areas Streets, roads, highways, and freeways All significant redevelopment projects: the addition or replacement of 5,000 ft 2 or more of impervious surface on an already developed site Retail Gasoline Outlets

12. WQMP Process, North Orange County

13. LID Hierarchy 1.On-site Infiltration 2.On-site Evapotranspiration 3.On-site Harvest and Reuse 4.On-site Bio-treatment 5.Off-site LID 6.In-lieu fee

14. Developing a Project WQMP

15. Infiltration

16. Evapotranspiration, Harvest & Use, Bio-Treatment

17. Regional Retention

18. Resources

19. Schedule Submit Proposed Model WQMP and Technical Guidance Document to Santa Ana Regional Board (March 22, 2011) Board Approval of Model WQMP (April 22, 2011) Model WQMP implementation (August, 2011) Submit Updated Model WQMP (SUSMP) to San Diego Regional Board (December, 2011)

20. Questions www.ocwatersheds.com office: 714 955 0670 24-hour hotline: 877 89 SPILL