Rain Garden LID Systems
Rescue Earth System
Flooding from urban run-off is mitigated by the installation of aesthetically appealing Rain Garden Low Impact Development (LID) Systems.
Rain Garden LID Systems
Rehydration of Urban Landscapes & Flood Control
A Rain Garden Low Impact Development (LID) System is a landscaped rainwater catchment that directs runoff water into purposely built depressions so that water infiltrates deep into the surrounding soil instead of flowing into a storm drain that empties into streams and river systems.
Rain Garden LID Systems are often paired with Permascapes, Bioremediation Systems and Public Places.
Why Rain Gardens?
Firstly, Rain Gardens are the most cost-effective way to rehydrate a diverse range of urban landscapes and mitigate flooding at the same time. Secondly, we should aim to have more rehydrated green landscapes in urban areas because they can help to significantly cool the local environment through photosynthesis and transpiration. In other words, urban greenery plays an irreplaceable role in local climate creation; and urban vegetation is a perfect (free) air conditioner that effectively cools and balances temperatures.
Because Rain Gardens are well suited to both private property and communal areas, rapid community-wide adoption of the practice is more likely. The other Water & Weather Initiatives that fit into an urban context include:
- Bioremediation Systems
- Reforestation & Trees
- Infiltration Swale Systems
- Leaky Check Dam Systems
- Ecosystem Restoration
All of the Water & Weather Initiatives listed above can be paired with Rain Garden LID Systems. For example, some Rain Gardens have a large berm and are modified Infiltration Swale Systems while others include Leaky Check Dam Systems that slow water flow and filter out soil and organic matter. Some may be part of a Permascape (Permaculture Landscape) built by Permablitz volunteers.
Rain gardens can also be wild wetlands or peat bogs! We believe that purpose built and regeneratively restored wetlands could be an effective urban flood prevention strategy, and be a valuable wildlife habitat in nature corridors. Both the Ecosystem Restoration and Reforestation & Trees Initiatives can thus be paired with Rain Gardens.
Urban Forests are a dense collection of trees in an urban area often with dense canopy that can rapidly cool the local environment especially if they are growing in a well hydrated landscape. Infiltration Swale Systems can be planted with trees — this is the predominant practice with Permaculture Swales. Another version is Enhanced Tree Pits with below ground ‘french-drain’ styled storage for excess water!
Although not related to Water & Weather Initiatives, Walking & Cycling Paths and Public Places / Commoning Initiatives are well suited to be paired in the design process as they can benefit from the aesthetically pleasing environments created by Water & Weather Initiatives.
Rain gardens absorb rainwater, so they can help:
- add an aesthetic landscape feature with many planting and design possibilities
- recharge groundwater
- protect neighbourhoods from flooding and drainage problems
- keep streams clean by reducing the amount of polluted stormwater that goes into streams from storm drains (see bioremediation)
- provide habitat for bees, birds, butterflies and other wildlife
- reduce the carbon footprint of the region
- cool local environments especially if the infiltrated water is used by trees — and trees clean the air and help make rain!
Curbside & parking lot Rain Garden LID Systems are becoming more common throughout the world.
A strong motivation to implement the rapid deployment of Rain Garden LID Systems is to mitigate the disruptions in the local watershed hydrology caused by impervious surfaces and reduced natural vegetation. Rain Garden LID System features are purposely designed using a combination of natural and constructed materials to facilitate bioremediation and other functions provided by natural system. Rain gardens are often planted with native plants so that they provide habitat for birds and insects.
In the context of the Rescue Earth System, Rain Garden LID Systems are an important Small Water Cycle hydration strategy as they infiltrate rainwater close to where it falls, increasing local ground water, which in-turn facilitates higher rates of transpiration from trees and plants planted in and near to the Rain Garden — this is especially evident in dry periods when more cooling is desirable.
Urban stormwater from paved areas such as roads most often contains a variety of toxic contaminants. The removal of these toxic contaminants is achieved by using Bioremediation LID System which includes a Rain Garden LID System