Storm Water BMPs
BMPs area site development friendly methods that encourage developers to landscape their projects site in such a way as to maintain existing run off rates at predevelopment levels while at the same time adding to the visual appeal of the property through the use of landscape plants and design. This method of site construction favors nature and works to utilize natural methods for controlling site development impacts. LID principles driving the developments of this code include
- better site design
- minimization of impervious surfaces
- protection of natural drainage features and existing tree vegetation
- reduce land disturbance activities
- promote low maintenance landscaping that reduces the use of herbicides, fertilizers, pesticides, and lawn grass
- protect stream banks and lake edges
- reduce storm water time of concentration at site outfalls.
The emphasis of the LID storm water beset management practices in this code uses non-structural methods of storm water management which also can be called 'micro-methods' of storm water management. These methods are best used on small parcels of land where available space is limited and decentralized drainage is practical and efficient. This is often the case in the city and suburban fringe where landscape codes are utilized for better land use practices and site design performance on small sites generally less than five (5) acres in extent. Non-structural methods do not use complicated engineering formulas to calculate water flow and capture and release but design based strictly upon volume storage calculations. Non-structural methods are designed according to the principle that trapping minor amounts of rainwater where it falls, or close to where it falls, reduces the volume headed downstream.
Decentralized storm water management is based upon principle of ground shaping, surface materials, selection, recharge capability improvements and vegetation plantings to modify the infiltration capabilities of grassed landforms, beds and planted buffers. These earth friendly methods that replicate nature's methods of storm water management make it easy for landscape architects, engineers or contractors to design site facilities to better detain, retain, and infiltrate storm water. Landscape design practices also make it easy for landscape contractors who build and plant projects sites to manipulate ground surfaces to capture rainfall. Non-structural methods allow for better site design, open space design, urban forestry, buffer zones, zoning, and ordinance compliance all of which are common procedures for managing minor storm water flows.
