permaculture

[Keith Johnson <keithdj@mindspring.com>]

Paul,
With an anticipated total population of 150-200 people (presently 50), a pond is unsuitable for the provision of drinking water, thus the tanks for spring water. That hasn't, however, stopped us from creating, at present count, four sizeable "lined holes in the ground" (see Permaculture Activist # 44 and the article "I'll have a Carpet Sandwich Please, Hold the Water" for the story on our process), ie, ponds whose multifunctionality will provide irrigation, fire control, fish, swimming and other amenities. These are certainly much cheaper per volume and definitely the way to go for your needs. Plans are for as much as 5 acre/feet in additional ponds. At present we have only two acres cleared for field agriculture with a potential of another 25 (currently in 60yr old forest). We have a comparable amount available for orchards also in forest.

Lining a pond needn't be as expensive as the figure you quote ($465) if you use old, off-gassed carpets and cheap builder's plastic as we describe in the article cited above.

Back issues of the activist can be ordered by sending the appropriate amount (check or money order in US funds) to: The Permaculture Activist, PO Box 1209, Black Mountain, NC 28711 The issues mentioned are $6 each, p&h included. For more details on back issues go to http://www.permacultureactivist.net/backissues.html
Keith

Paul A Cross wrote:

Keith, thanks for the info on the tank. In looking at your costs, I wonder if it would have been cheaper to dig a hole, line it with pond liner, and then pump out of that. Since I'm in a cold semi arid climate at 7400 feet, I figure the tank would need to be indoors so the water wasn't frozen when we started needing it in January. I figured we'd get a backhoe to dig us a hole 22 feet square by 6 feet deep. We'd line with a pond liner at a cost of $465, then build a top for it. We'd erect the greenhouse over the covered hole, and route the water appropriately. The backhoe will cost perhaps $1000. If we can cover the pond with a walkable top for $500, then I've got a 20K gallon tank at $2000 plus the cost of a pump. That's cheaper than your tank, less labor, and twice the capacity. I would like to order the Activist #37, so send me the details on how to order and I'll follow through. And please let me know once the video is available. I might do above-ground tanks for transferring from the main house to the greenhouse tank. Thanks again for all your help. Paul 

----- Original Message -----

From: Keith Johnson

To: Paul A Cross

Sent: Sunday, December 30, 2001 9:48 PM

Subject: Re: ferrocrete tank

 Paul,
The cost in materials was about $2400.00. Labor was all volunteer. I don't have all the figures, but it took about 8 days with an average of 5 people per day.  We plan to build at least 3 more tanks this size. Now that we're pretty good at it (this is my third, though the first two were much smaller), we will make a video of the next tank-building process and offer it to prospective builders. It's really not that difficult and the larger tanks are actually cheaper per gallon of water than the small ones. The 1,600 tank we built for our house was about $500 in materials and took about 12 days to finish. On that tank we used chicken wire as the armature for the mortar plaster. On the new tank we used expanded metal lathe, a MUCH superior material. We published an article on ferrocement tanks in the Activist a while back (#37, Sept '97). Back issues are still available for $6.

A fast and cheap tank (not permanent) can be made with heavy duty rebar mesh or heavy gauge stock fencing panels formed into a cylinder (probably not much larger than 5 or 6 ft high and 8ft in diameter) The joint in the side of the cylinder should be overlapped or even double lapped over the whole cylinder and wired VERY securely (Water is heavy. Don't underengineer). Attach used carpeting to the interior (and floor) of the cylinder (pile toward the inside) with wire ties (tied on the outside) and line with two layers of cheap 6 mil builders plastic. The carpeting (which could also be double thickness) prevents the plastic from sagging through the holes in the cylinder and also protects against punctures. If you've built it under a rain gutter, just wait for rain or fill with a hose.

Keith