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Re: Permeable Parking Surface




A few comments on the comments on my post, without reposting what could 
become a confusing hash.

l)  Swales increase in infiltration capacity over time, assuming that they 
are planted.  
2)  Ponds tend to gley-up--they do not function as swales very well.  
3)  Whatever the goal of government requirements, our goal as permaculturists 
is to increase infiltration wherever there is runoff.  Delay of runoff has 
some merit in terms of evening stream-flow fluctuations to something more 
habitable by aquatic life and trapping sediment (which then must be removed), 
but the system of simply fluctuating levels in ponds is rarely the 
permaculture option if it is possible to develop infiltration strategies 
instead.  

I suppose the ideal system holds all runoff that enters it and becomes fully 
dry the day before the rain that breaks the worst-case-possible drought.  
Where hybrid swale/pond systems are used, it is best to make the swales 
substantially shallower than the "permanent" water so that they can retain 
vegetation and therefore promote infiltration.  Area of swale to pond would 
be some double digit multiple or greater.  This could be especially 
convenient in clay soils where infiltration is slow, especially in relatively 
young swales, as mosquito fish could be maintained in the small pocket of 
permanent water to control, you guessed it, mosquitos.  In our swamp, when we 
have rising water I spend a bit of time each day netting those fish and 
innoculating new pools with them.  Retreating water is full of mosquito fish 
(which breed like guppies to which they are related), so there is little 
potential for mosquito build up.

For Mother Earth, Dan Hemenway, Yankee Permaculture Publications (since 
1982), Elfin Permaculture workshops, lectures, Permaculture Design Courses, 
consulting and permaculture designs (since 1981), and annual correspondence 
courses via email.  Copyright, 1998, Dan & Cynthia Hemenway, P.O. Box 52, 
Sparr FL 32192 USA  Internships. YankeePerm@aol.com  

We don't have time to rush.

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