Friday, June 28, 2013

Offending the Spring

or, how to keep spring production continuing.

Springs are like teenagers. They need encouragement, nurturing, and minimal push-back to keep them from running away. It's important when you want to develop a spring to not inhibit it's flow in any way. As we all know, water finds its own way. If you push water, it goes around you. If you dam up a spring to collect the water, it will find another route to come out or disappear entirely.  It is also important to safeguard the spring water from surface contamination, kind of like parental controls on the world wide web.
There are a couple of common ways to develop a spring. The most common way is to build a spring box. This is usually out of concrete, but any variety of other materials could be used so long as it can be secured from contamination. Water enters the spring box from a porous surface into the hill from which the spring emerges. This can be made by building in perforations in the concrete, or building a block wall with big openings between blocks. The important thing is to make sure that the outlet from the spring box is set at such a height that water does not accumulate above the spring source which would cause back pressure.
The other common method is to drive a perforated pipe into the hill and spring and capture water that way. Concrete grout is used to seal the pipe where it enters the hillside. Horizontal well drillers put these in all the time and they are quick and clean.
It's also important that you put an overflow in the piping after the spring box or spring pipe. This allows for times when you aren't using all the spring water, but don't want water to back up into the spring box.
Helpful hint. Oftentimes springs can be located by the presence of woodwardia ferns

Monday, June 3, 2013

Rope Pumps

One of the most interesting pumps I have seen for pumping water from depths that a a suction pump can't manage is the rope pump. By cranking the bicycle wheel, a continuous rope extends down into the well and back up through a PVC pipe. What allows the unit to pump are rubber gaskets on the rope at intervals, held in place with knots. When the rope enters the pipe, it lifts a column of water which then exits the pipe through a tee fitting above the well cover. Brilliant, simple, and manufacturerable almost anywhere.
The book, Providing Water, contains many such innovations appropriate to developing countries. Drawing by Xan Blackburn (