The City of Austell adopted its Post Development Stormwater Management for New Development and Re-Development Ordinance on January 5, 2015, that requires developments to address stormwater runoff quality and quantity impacts following construction resulting from the permanent alteration of the land surface as well as the nonpoint source pollution from land use activities.
The City of Austell is committed to the principles outlined in the City of Austell Development Standards. Recommendations of the Georgia Stormwater Management Manual are incorporated into the planning process in combination with the development regulations. The Georgia Stormwater Management Manual was adopted by City Council action on February 2, 2004.
Green Infrastructure and Low Impact Development
Managing stormwater with green infrastructure (also termed low impact site design) seeks to manage rainfall where it falls, reducing or eliminating the need for regional detention ponds and flood controls. These approaches offer a variety of other benefits when compared to traditional stormwater management approaches including, but not limited to increased protection of local streams and watershed; promotion of groundwater recharge; more flexibility of site layouts; enhanced aesthetics and overall cost savings than traditional stormwater management approaches.
Low Impact Development is a flexible technique that can be applied to nearly any site, including both infill/redevelopment sites and new development. When used in combination with site techniques, these regional-level techniques can reduce runoff and associated pollutants across a watershed.
Examples of Low Impact Development techniques include:
- Disconnected impervious surfaces: Runoff from rooftops, sidewalks, driveways, and roads can be directed to landscaped areas or porous pavement to promote infiltration and reduce stormwater volumes.
- Preservation of open space/natural features: Areas of a development site that will not contain buildings or other infrastructure can be protected from clearing, grading, and other construction-related impacts, reducing the amount of disturbed land and maintaining mature vegetation.
- Bioretention: Also known as rain gardens, biofilters, bioswales, and bioinfiltration practices, these are landscaped depressions that collect runoff and manage it through infiltration, evapotranspiration, and biological uptake of nutrients and other pollutants.
- Flow-through planters and tree boxes: Planters and tree boxes enhance streetscapes and courtyards with attractive vegetation and shade and also provide pervious areas for rainfall interception and stormwater infiltration.
- Porous pavement: A variety of paving surfaces have been developed that contain pore spaces that store and infiltrate runoff. Pavement types include porous concrete, porous asphalt, and interlocking pavers.
- Water harvesting (rain barrels, cisterns): Rainfall from rooftops can be collected via downspouts and stored for reuse. Rain barrels are typically used to store water for landscaping, and cisterns, which offer more storage volume, can store water for toilet flushing, landscape irrigation, or other gray water applications.
- Ecoroofs: Also known as green roofs, ecoroofs consist of a layer of soil and plants installed on a roof surface. Ecoroofs provide stormwater retention, reducing stormwater volumes and promoting evaporation and transpiration. Ecoroofs have been shown to have energy-saving benefits and help to reduce the heat-island effect in urban areas.
- Low-input landscaping: Choosing native plants that are easy to maintain and adapted to local climate and soil conditions decreases or eliminates the need for watering, fertilizers, and pesticides.
The City of Austell will actively encourage the use of greenspace infrastructure through a variety of mechanisms. One of the first tasks that the City will undertake an evaluation of the City’s development regulations (such as transportation design specifications, plumbing codes, landscaping requirements, and other standards) that might prohibit the use of Low Impact Development practices. If incompatible language is identified, the City of Austell will develop new code language, propose changes to the zoning or development ordinance, and/or develop a separate stormwater ordinance that outline the new standards.
In addition, the City of Austell will work to identify possible incentives that can be offered to encourage Low Impact Development Implementation. Incentives can be in the form of density bonuses, reduced size of required drainage infrastructure, discounted utility fees, and tax credits.
Demonstration projects will hopefully be implemented by private developers during this reporting cycle. The projects will be monitored for effectiveness and suitability of design. Demonstration projects will identify techniques that work well in local conditions and show developers and citizens the potential associated with attractive stormwater Best Management Practices and instill confidence in their performance.
Municipalities have jurisdiction over development activities in the right-of-way and on public lands, which allows greater design flexibility and more reliable maintenance using municipal crews. Low Impact Development projects adapt well to linear applications (streetscapes, courtyards, medians, etc.) and small-scale open spaces. The City will set a good example, show confidence in the use of new technology, and demonstrate success with pilot projects in the public right-of-way as opportunities come forward. The City of Austell will also consider adopting Leadership in Energy and Environmental Design (LEED) Green Building Rating System standards for all municipal building and development projects within the new permit cycle.
Green Infrastructure and Low Impact Development Structure Inventory
Staff will develop an inventory of privately-owned non-residential and publicly owned water quality-related Green Infrastructure and Low Impact Development structures located within the City. The inventory will include, at a minimum, bioswales, pervious pavements, rain gardens, cisterns, green roofs, and any other structure deemed appropriate. Following the development of the initial inventory, new structures will be identified through the plan development process.
Green Infrastructure and Low Impact Development Inspection Program
Beginning June 2017, inspections will be conducted on 100% of the total privately owned non-residential and publicly owned Green Infrastructure and Low Impact Development structures within a five year period. Annually, the Stormwater Management division will inspect 20% of the inventory.
Low Impact Development Post-Development Fact Sheet
Post-Development Stormwater Management for New Development and Re-Development Ordinance