(made category of swales and linked to the wikihow article... Thanks Lucas.) |
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{{Wikipedia p|Swale (geographical feature)}} | {{Wikipedia p|Swale (geographical feature)}} | ||
Swales, also know as bioswales are a shallow troughlike depression that's created to carry water during rainstorms or snow melts. -- Wiktionary. They are rapidly becoming a staple in the design of sustainable urban landscapes due to their number of advantages. Many governments are begining to require bioswales along with other "best management practices" | |||
A means of [[groundwater recharge]], a favorite of [[Bill Mollison]] [[permaculture]] pioneer. | = Advantages = | ||
* A means of [[groundwater recharge]], a favorite of [[Bill Mollison]] [[permaculture]] pioneer. | |||
* Asthetically pleasing | |||
* They treat water flowing through them | |||
:* oils in the water stick to the foliage where they break down over time. | |||
:* sediments get traped and filtered out | |||
=Design Recommendations= | |||
* Single swales can not treat areas greater than 10 acres. | |||
* Impractical on steep slopes. | |||
* Requires thick vegitation. | |||
* The swale should have a treatment area larger than 4% of the impervious surface it treats. | |||
* The treatment depth should not exceed 2/3 the depth of the grass in the swale | |||
* The dimensions of the swale should be checked with Manning's equation and a value of .25 for "Manning's n" | |||
* Care should be taken in the design of the inlet and outlet of the swale | |||
* A 6% down slope grade is ideal to insure that the velocity of the water in the swale does not become excessive. | |||
* the side slopes of the swale should not exceed 3 to 1 (three feet over for every one foot down) | |||
* The swale should have a maximum treatment width of 10ft with parallel swales used if greater widths are necessary | |||
== External links == | == External links == | ||
* [http://www.hialeahfl.gov/dept/streets/stormwater/related-info/swale.htm Save the Swales - WHY MANAGE RUNOFF?] (the site of a local government in Florida). | * [http://www.hialeahfl.gov/dept/streets/stormwater/related-info/swale.htm Save the Swales - WHY MANAGE RUNOFF?] (the site of a local government in Florida). | ||
* http://www.wikihow.com/Dig-Swales | * http://www.wikihow.com/Dig-Swales | ||
*[http://www.eoainc.com/download/ACCWP_C3_Technical_Guidance_090506-300dpi.pdf Alameda County Stormwater Technical Guidance] has more details for the design of Bioswales and other best management practices. | |||
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Revision as of 01:51, 15 March 2009
Swales, also know as bioswales are a shallow troughlike depression that's created to carry water during rainstorms or snow melts. -- Wiktionary. They are rapidly becoming a staple in the design of sustainable urban landscapes due to their number of advantages. Many governments are begining to require bioswales along with other "best management practices"
Advantages
- A means of groundwater recharge, a favorite of Bill Mollison permaculture pioneer.
- Asthetically pleasing
- They treat water flowing through them
- oils in the water stick to the foliage where they break down over time.
- sediments get traped and filtered out
Design Recommendations
- Single swales can not treat areas greater than 10 acres.
- Impractical on steep slopes.
- Requires thick vegitation.
- The swale should have a treatment area larger than 4% of the impervious surface it treats.
- The treatment depth should not exceed 2/3 the depth of the grass in the swale
- The dimensions of the swale should be checked with Manning's equation and a value of .25 for "Manning's n"
- Care should be taken in the design of the inlet and outlet of the swale
- A 6% down slope grade is ideal to insure that the velocity of the water in the swale does not become excessive.
- the side slopes of the swale should not exceed 3 to 1 (three feet over for every one foot down)
- The swale should have a maximum treatment width of 10ft with parallel swales used if greater widths are necessary
External links
- Save the Swales - WHY MANAGE RUNOFF? (the site of a local government in Florida).
- http://www.wikihow.com/Dig-Swales
- Alameda County Stormwater Technical Guidance has more details for the design of Bioswales and other best management practices.