& Community Design LSU Green Laws Research Project Green Laws Louisiana Department of Agriculture & Forestry EBR Parish Tree And Landscape Commission Louisiana Department of Agriculture & Forestry EBR Parish Tree And Landscape Commission Photographs: Live Oak Gardens Ltd. Abbey Associates Landscape Architects ti tl e Dudley Thiel cover

Community Landscape Codes Landscape codes or green laws are special parts of a community’s zoning ordinance. Certain provisions are written to influence the design of ‘on-site storm water management facilities’ and to make improvements to the environment of urban areas Notable codes include Raleigh, North Carolina; North Myrtle Beach, South Carolina; Stone Mountain, Georgia

On-Site Storm Water Management Facilities The detention, retention or management of storm water on-site before discharging it to a public stormwater disposal system such as an underground storm drain pipe, open ditch or drainage canal is becoming an important part of landscape design in urban areas. Storm water management can also be considered the use of ‘best management practices’ (BMP”s) involving a variety of sustainable drainage methods including storm water buffers, parking lot detentions, storm water groves, rain gardens, bioswales, porous paving, infiltration trenches and irrigation storm water collect and recycling vessels.

The Problem 1. Too little on-site retention to the right for amount of runoff

The Problem 2. An unaesthetic solution to on-site storm water management

The Problem 3. New development with no on-site water retention. A ‘curb and gutter catch basin system’ directing water to an underground drain line.

Purpose of On-Site Storm Water Management Facilities To reduce post development runoff To increase on-site water storage and disposal. To capture and store non-point pollutants originating on development sites. To protect water and aquatic resources from pollution. To increase sustainability of newly developed sites. To protect the environmental and general welfare of the public.

Types of On-Site Storm Water Management Facilities Dry Detention Ponds Wet Retention Ponds Vegetated Swales Permeable Paving Underground Storm Water Chambers Green Roofs or Disconnected Rooftops Rain Gardens Storm Water Groves Preserved Wetlands Irrigation Cisterns

Code Writing Essentials Purpose- Location- Size- Site Area, Volume Runoff Information- Slope, Direction,Velocity, Intensity, Duration, Volume, Design Calculations Design Storm, Permeability Ratio, Capture Rate, Release Rate Material Specifications- Plants, Soil Structure, Grading, Facility Design Related Elements- Maintenance Plan

A Visual Gallery of On-Site Water Management Facilities

Visual Gallery 1. Small retention pond for parking lot runoff, Pensacola, Florida

Visual Gallery 2. Detention Basin. Fairfax County, Virginia. Is the fence Necessary for public safety?

Visual Gallery 3. An Aesthetic Amenity Retention Basin. Clearwater, Florida

Visual Gallery 4. Pepsi Co. Retention Basin. New York, New York

Best Management Practices Goals Use Sustainable Drainage Systems (SuDS) rather than curbs, catch basins and pipe when possible. Use Low Impact Development (LID) methods that preserve natural site resources Decrease impervious surfaces, Increase pervious surfaces. Design Bio-swales, Rain Gardens, Infiltration Trenches, and Storm Water Buffers Preserve natural wetlands, Rain Groves and grassy slopes. Mimic the site’s Pre-development hydrology Determine an appropriate capture rate for each community. Capture rainwater from roofs and parking lot surfaces first. Use vegetated swales to direct water.

Typical Code Specs Stone Mountain, Georgia Sec Landscaping and open space plan. A detailed landscaping and vegetation plan describing the woody and herbaceous vegetation that will be used within and adjacent to stormwater management facilities and practices. The landscaping plan must also include: the arrangement of planted areas, natural and greenspace areas and other landscaped features on the site plan; information necessary to construct the landscaping elements shown on the plan drawings; descriptions and standards for the methods, materials and vegetation that are to be used in the construction; density of plantings; descriptions of the stabilization and management techniques used to establish vegetation; and a description of who will be responsible for ongoing maintenance of vegetation for the stormwater management facility and what practices will be employed to ensure that adequate vegetative cover is preserved.

Typical Code Specs North Myrtle Beach, South Carolina Sec (b) [Approval of stormwater management plans.] Stormwater management plans will be approved, consistent with procedures in this article, when the applicant has demonstrated that the proposed development activity is designed to meet each of the following performance standards: (1) To encourage the use of "best management practices," i.e., maximum use of on-site storage facilities to reduce runoff rates and volumes, and minimize erosion and sedimentation. (2) To design, construct, and maintain stormwater management facilities in a manner, which controls post-development runoff so as to simulate the time-discharge function for predevelopment runoff, based on the twenty-five-year, twenty-four-hour design storm. (3) To design, construct, and maintain stormwater management facilities in such a manner that erosion or sedimentation does not exceed natural or predevelopment conditions. (4) To ensure that downstream drainage systems are adequate to handle any increased flows and to provide off-site improvements where necessary to comply with the City of North Myrtle Beach Storm Water Master Plan. (5) To design, construct and maintain stormwater management facilities consistent with mosquito control objectives and programs when not in conflict with this article. (6) To protect the water quality of the surf and the physical characteristics of the beach area by minimizing the rates, volumes, and velocities of stormwater entering drainage systems discharging onto the beach.

Typical Code Specs Raleigh, North Carolina Sec (2) The maximum impervious surface coverage of the lot, including any existing impervious surfaces, is no more than fifteen (15) per cent and the remaining pervious portions of the lot are utilized to convey and control the stormwater runoff of the lot to the maximum extent practical. Any lot which is exempted from the runoff control requirements by subsection (b)(2), shall comply with all the requirements of subsection (a) whenever: a. The exempted lot is subdivided; or b. The exempted lot size is reduced by recombination; or c. Impervious surfaces on the exempted lot equal or exceed fifteen (15) per cent.

References Raleigh, North Carolina Code of Ordinances, Part 10 Zoning, Sec – Sec North Myrtle Beach, South Carolina Code of Ordinances, Chapter 13 Stormwater Management and Erosion Control, Article II Stormwater Management Plan, Sec – Sec Stone Mountain, Georgia, Code of Ordinances, Chapter 28 Stormwater Utility, Article II Post-Development Stormwater Management for New Development and Redevelopment, Sec – Sec

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