1. Pierce Rigrod, M.R.P Environmentalist IV NH DES Concord, NH
LRPC Workshop, Meredith Community Center, Meredith, New Hampshire
Low Impact Development:
Education and Local Adoption
Pierce Rigrod, M.R.P
Environmentalist IV
NH DES
Concord, NH
January,

4. LID Stormwater Practices
Source: EPA (2007) Reducing Stormwater Costs Through Low Impact Development (LID) Strategies and Practices (EPA-841-F )

5. Conventional Subdivision Open Space Subdivision
Not so good.
Open Space
Subdivision
Good.

6. LID: Status of NH Adoption
LID is an effective and efficient approach to stormwater
LID may help mitigate extreme climate events and be more aesthetic (design)
Introduction of bio-retention technology in Prince George's County, Maryland, in the mid-1980s
Ask for hands on LID regs adoption.
Who has adopted LID regulations?

7. Science-based, training and LID Performance Data

8. What’s the Hold Up? (canvass from some partners)…
1. Lack of education on what LID is.
2.  LID is not viewed as a viable option due to cost, maintenance.
3.  There isn’t enough specific language or guidance on the adoption of LID regulations.
4. Lack of support or regulatory insistence from state or federal governments.
5.  Engineers are not adopting it quickly.
6. Disinterest in new regulations.
Hypothesis

9. Education ROLL THE FILM
NH Citizen Planner training modules on “Forging the Link”
Discusses economic issues and potential of LID to mitigate climate impacts
ROLL THE FILM

10. Making LID Happen

11. Explore Non-Regulatory Opportunities to Work with Landowners
And, there are opportunities to work with landowners to improve water quality. In these examples, Youth Conservation Corps have installed simple BMPs that reduce erosion and sedimentation within Balch Pond in Sanbonville, NH (Action-Wakefield)

12. York LID Ordinance: Simple
Low Impact Design. “Each applicant is required to submit a statement  to the Planning Board documenting proposed Low Impact Design (LID) for the site, which will help to reduce stormwater volumes and help to enhance stormwater quality.”
“LID includes, but is not limited to green roofs, rain gardens, tree wells, infiltration basins, and permeable pavement.  The applicant shall submit technical documentation about the suitability of such designs with the request for LID features.” 
Simple…but doesn’t by itself control design

13. Rooftop Runoff 77 Not so good. Good. Good.
Another alternative to managing rooftop runoff is to drain the runoff directly into rain barrels, which can store the water for later use in gardens, yards, or for house plants.
Good.
Source: Center for Watershed Protection 77

14. Street Width
Many municipalities continue to have local codes or regulations in place that discourage or even prohibit impervious cover reductions
Not so good.
Residential streets should be designed to be as narrow as possible based on future traffic volumes without compromising safety.
Typical streets are often excessively wide, increasing traffic speeds and making streets unfriendly to pedestrians.
Good.
Source: Center for Watershed Protection 73

15. Parking: Grading and drainage for LID parking lots directs runoff
to bioretention and pervious pavement areas.
Parking:
When designing large parking lots, it is best to break up and direct flows to multiple LID features. During the grading process, care should be taken to avoid compaction of areas identified for bioretention areas.
A patterned steel grate inlet conveys flow under a pedestrian walkway.
A curb cut inlet directs stormwater runoff into a biofiltration planter.
An overflow outlet conveys runoff that exceeds the bioretention area capacity.
Continuous cross slope conveys the full aisle to an adjacent swale. Crowned slope conveys half of each aisle to the adjacent swale. Inlets and outlets direct runoff into, and out of, bioretention areas. Proper placement of inlets helps to
spread runoff over the bioretention planting areas, which slows the flow and reduces erosion. Outlet, including overflow, structures direct excess runoff to the storm drain system or street. During construction, avoid placing overflow structures flush with the soil, which prevents the desired retention of stormwater in the bioretention area.
Photo Source: Kevin Perry, Bureau of
Envronmental Services, City of Portland
Source: Illinois Environmental Protection
Source: Bill DePoto
Anatomy of a LID Parking Lot

16. Parking & LID
Minimize impervious surfaces and uses site grading to direct
runoff to landscaped areas where LID strategies can be utilized
Break up and direct flows to multiple LID features.

17. Permeable Paving Runoff Reduction Grass pavers Paving stones
Porous asphalt
Pervious concrete
Reinforced turf

18. Infiltration: Not!
Somersworth, NH Site Plan Regs

19. LID Residential Design Element: Shared Driveways Reduce Impervious Area

20. Somersworth Site Plan Regulation: Getting Support Over Time
The City of Somersworth encouraged LID for many years with several successful projects.
Before even drafting regulations, the City staff visited UNH/SC
Discussed voluntary adoption of LID with developers
Now that we know what they do, how did we adopt them. We took a capacity building approach in Somersworth.
LID regulations proposed in 2011 passed City Council unanimously 20

21. New LID Commercial Development in Somersworth
Mature landscaping utilized throughout
All 719 parking stalls and access aisles constructed with porous asphalt
From a site development perspective the lot is full. From a stormwater perspective, visualize only the buildings being impervious and some of them will collect roof runoff and reuse as irrigation.
Disconnected stormwater infiltration
Source: David Sharples, Somersworth Planning Director

22. Somersworth, NH LID Site Plan Regulations
Requires groundwater recharge
Requires the best available treatment with the least impact
Requires careful analysis of the onsite conditions
Requires practices that maintain/improve water quality
Requires an Operation and Maintenance Plan with an annual reporting requirement
GWR prohibited in high load areas, gas stations
Source: David Sharples, Somersworth Planning Director 22

23. Acton,ME Stormwater Mgt Ordinance (proposed)
“Impervious cover should be disconnected from the stormwater drainage network, through such techniques as infiltration, sheet flow over a pervious area, or other approved LID techniques.”

24. LID in your local codes? Subdivision regulations Site plan regulations
disconnection and retention of mature natural landscape
Site plan regulations
Parking, curbing and road design
Stormwater ordinance
LID practices
Photo: Horsley-Whitten, Inc.
RSA 674:16, Grant of Power, RSA 674:17, Purposes of Zoning Ordinance, and RSA 674:21, Innovative Land Use Controls.

25. LID Resources for Ordinances
NH DES Innovative Land Use Guide – Post Construction Stormwater Ord Template –
MA Smarthgrowth Toolkit –
Model Stormwater Standards for Coastal Watershed Communities
City of Somersworth – Site Plan Regulations
Town of York, ME – LID Ordinance
Town of Acton, ME – Stormwater Ordinance