We at Landscape Invocation by no means call ourselves experts; we are current students and will forever be students of design. However, exposed to the forefront of contemporary practice this blog allows us to inform the public of outdated and irresponsible techniques and showcase effective alternatives of today and upcoming years.
Storm Water Drainage: Part 1
Current trends of storm water drainage, in some areas, ineffectively treat storm water before it enters a water body. Many locations, such as below, simply collect storm water and drain to the nearest water body. Applications such as this do a good job of getting rid of water quickly and efficiently (in some cases). However, the collection of this water comes from roads, sidewalks, turfed areas, etc. carrying pollutants such as oil, sediments, fertilizers and loose garbage directly into what is now a contaminated water body. The constant flush of these materials in to water bodies has detrimental effects on vegetation, wildlife, natural resources and are nonetheless, eyesores.
Outdated Technique: In the images below, the water from two roads and surrounding sidewalks feeds directly in to a pipe that goes in to Lake Alice or the grassed swale that swiftly pours contaminated water in to the lake.
Water flows directly from street storm drains in to Lake Alice without any filtering or reduction of flow.
Any water that does not flow in to the storm drains is flushed to this grassed swale that quickly pours out in to the “Nature Preserve” area of Lake Alice.
Trends of storm water management are slowly changing towards more efficient and natural techniques. People have figured out that the best way to take care of storm water, even in an urban environment, is by mimicking natural systems. In most contemporary systems, instead of flushing water directly to a pipe, pond, or steep slope it is moved off streets and slowly filtered through vegetated swales and ponds. The slower detention of water allows the vegetation to filter toxins out of the water and limits the amount of immediate water volume that pours in to a water body; helping to alleviate chances of flooding. Needless to say, exposed water and vegetation create a better visual than concrete and grass.
The next set of images are from NE Siskiyou Green Street project in Portland, Oregon designed by Kevin Robert Perry. This project removes the typical curb and gutter design and replaces it with vegetated swales directly fed from the street by curb cuts. Within the swales are small berms that separate it in to sectors. The water slowly fills each sector and either filters down to the ground or over flows in to the remaining sectors; by the time any water reaches a water body, it is filtered. This technique is simple and cost effective due to reduction of city infrastructure, sustainable because it deals with storm water locally instead of flowing it to where it does not belong, and aesthetically pleasing compared to a black metal grate and water flowing over rocks and plants instead of concrete.
Curb cuts allow water to immediately move in to the swale, matching the efficiency of a curb and gutter.
These simple berms help establish slow drainage and successful percolation.
During a heavy storm event, the sectors fill up and create a beautiful rain garden.
Marco Ancheita recently received a bachelor’s degree in Landscape Architecture from the University of Florida and is a contributing writer to Landscape Invocation. He is currently a Master’s student of Architecture at the Georgia Institute of Technology. His interests and goals lie in the realm of Urban Design;he is firm believer that successful urban design requires a true multidisciplinary approach and, even more, a multidisciplinary education.