Stormwater Management Plans
Article 23 of the City’s Comprehensive Zoning Ordinance (CZO) provides requirements for new development and major redevelopments to address the stormwater runoff that would be generated from their locations. Developing property with buildings and paving limits the ground’s ability to absorb runoff, shedding excess stormwater into the City’s drainage system and overtaxing the network of pipes and pumps; causing street flooding. This barrier then sheds water into the City’s municipal stormwater system which has to be removed. By applying detention and retention standards to development, much of the stormwater that would be sent into the City’s stormwater system will be kept on-site and either absorbed into the soil or slowly released into the stormwater system after the rain event has ended.
Stormwater Management Plans must be developed in conjunction with any development or redevelopment project that proposes or contains either 1) 5,000 square feet or more of impervious surface; or, 2) a total site area of one acre or greater. The full requirements of the Stormwater Management Plan can be found in Section 23.3 of the CZO. Additional restrictions on lot coverage and paving can be found within the standards of individual zoning districts, but are summarized here.
The goals of these regulations are to:
A. Assist in the development of a sustainable New Orleans by encouraging sustainable practices for landscape design, construction and landscape maintenance.
B. Reduce urban runoff and mitigate the effect of new development, redevelopment, or infill development on the existing drainage system by ensuring the preservation of permeable surfaces and requiring the installation of stormwater Best Management Practice (BMPs) to slow surface flow of stormwater runoff and promote filtration, plant uptake, absorption, and infiltration into sub-soils to reduce subsidence rates.
C. Increase compatibility between abutting land uses and between land uses and public rights-of-way by providing landscape screening or buffers.
D. Provide for the conservation of water resources through the efficient use of irrigation, appropriate mix of plant materials, recycling water elements, and regular maintenance of landscaped areas.
E. Protect public health, safety, and welfare by preserving and enhancing the positive visual experience of the built environment, promoting urban forestry, providing appropriate transition between different land uses, preserving neighborhood character, and enhancing pedestrian and vehicular traffic safety.
F. Reduce the urban heat island effect, enhance the local micro-climate, increase species biodiversity, reduce consumption of energy by proper placement of shade trees and incorporate tree canopy concepts as set forth in the City’s Master Plan.