Well-established agricultural keyline design
Keylines are shallow grooves placed into the soil with an agricultural keyline plow. They can be done on contour or at a very slight grade and serve to slow or halt runoff of water and topsoil while promoting infiltration and absorption. In the designed landscape, these can be applied in open spaces and for erosion prevention.
Parking areas can be redesigned to allow more dynamic use of the space. From nearly every point in an urban center, you can often see a parking lot or garage. These spaces are designed for a single purpose – to store our vehicles while we navigate the city otherwise. Conventionally designed parking lots currently yield 100% runoff to the existing stormwater system: gas, oil, salt, cigarette butts, and all. Whenever a space serves one single function, there is an opportunity. Here are some of those opportunities with parking lots.
Porous surfaces can be used in place of non-porous surfaces to allow increased absorption for reduced runoff on surface-level lots. These lots can be designed with porous surface materials that are recently becoming available to allow water to filter through the surface instead of into a drain.
Vegetated sections can be designed into lots that capture drainage to utilize and allow infiltration into the soil. These can be constructed on contour or in a depression to capture as much water as possible.
Parking garage redesign can reduce runoff from the building, utilizing some of the previously mentioned strategies. The first approach is the addition of a green roof to the top of the building, creating an attractive space that can become an attraction in itself and allowing for partial or complete absorption of precipitation. A second approach could be the construction of runoff areas outside of the building that capture and retain runoff. These could take the form of planted boxes that capture and utilize the runoff and provide design aesthetic to the building, with any excess runoff dripping down to the planted box at the next level. There are many other possibilities to reduce or better utilize the runoff from parking areas.
There are many other ways that water can be utilized as the precious resource it is, especially in urban areas. All we need is a little creativity and understanding to revolutionize the way we view and utilize water in the city.
On the small scale these strategies will help to reduce erosion and reduce maintenance of the existing landscape by providing a resilient form of irrigation. On a large scale these strategies will enhance the health and vitality of the urban core while lessening the impact of combined sewer overflow and flooding events in waterways. Picture the enhanced greenspaces that are assisted through appropriate stormwater techniques as a giant lung that filters the dense urban air for a healthier city.
Oh, and thanks for having a glass of water with me – so refreshing. It’s as if it were life-giving!
Be sure to stay tuned for part three of this four-part series: Strategies for Suburban Stormwater Mitigation!
Ready to take action? Have other ideas? Leave a comment below and share with everyone!
“We need nature as much in the city as in the countryside.
In order to endure we must maintain the bounty of that great cornucopia which is our inheritance. It is clear that we must look deep to the values which we hold. These must be transformed if we are to reap the bounty and create that fine visage for the home of the brave and the land of the free. We need, not only a better view of man and nature, but a working method by which the least of us can ensure that the product of his works is not more despoliation.”
-Ian McHarg, Design with Nature
The US EPA has some great resources on understanding runoff and associated risks, along with some practices to implement as solutions.
Urban Nonpoint Source Pollution – a factsheet outlining how urban pollutants and impervious surfaces affect water systems.
Managing Urban Runoff – a list of resources to design more responsible urban runoff systems.
Green Infrastructure – an exhaustive resource of tools, training, literature, and case studies on ‘green’ design. Essentially, a bunch of different strategies to help mitigate runoff issues and other issues in urban design. Definitely worth at least a glance.
Low Impact Development (LID) – another resource outlining strategies to provide more responsible design in urban areas.
Image Credits: Flickr Nicole Yeary, Noelle Murata, Wayan Vota, eutrophication hypoxia, diane cordell, kcxd, Sheri Miklaski, Rory Hyde, edibleoffice, Milkwood.net, Khanh Hmoong, Milkwood.net