>Sand & Gravel Harvesting
The dry wash that cuts my land in half supplies all of my sand, gravel and stones for concrete
and other projects. However, after harvesting all of the sand near to my building site, the next deposits
were much farther away. What the wash needed was a series of dams just large enough to slow the water down and let
sand and gravel drop out.
I spent a day moving huge boulders into lines across the wash, and I dug some out of the
hillside and rolled them down into the wash. In the end I had five dams, spaced about 20 feet apart, in the section
of wash closest to the building site and upstream. But I had never seen this wash flow with water - not in five
years. Would I ever get any more sand and gravel?
Timing is everything, and I didn't have to wait long to see what a flash flood does in my wash.
Well, I wasn't there, but I came the next day and... my dams were full to the top with new sand and gravel. Yes! I
love it when things work.
Getting it to the job site is great exercise. I strapped a 5-gallon bucket to a backpack frame
and place it on an upturned 60-gallon barrel in the wash, the bucket rests on the barrel. A gallon paint container
with top removed (scoop) waits on the barrel full of sand and gravel. I dump it into the bucket for weight and the
backpack won't fall off the drum.
Now I scoop up four more loads and the bucket is nearly full. Then I insert a four foot strip
of plastic sheet from a sign and coil it around to extend the top of the bucket another 10 inches. Now it will hold
another four scoops, making it close to 100 pounds. I slip into the backpack straps clip the belt and lift up the
load. Then it's about a 200-foot walk and about 50 feet higher to the house, where another barrel is waiting to set
it on. Leaning on this barrel is a 2x4 frame with hardware cloth screwed to both sides. One side is 1/4", the
other, which has a 2-inch gap at the bottom, is 1/8", and it's the lower one.
I tip the bucket over slowly and the sand and gravel cascade to the top screen, and I tap the
lower one to help the sifting. In a couple of minutes, the load is sifted into three piles, coarse, fine and sand.
Coarse is over 1/4", fine is 1/4" to 1/8" and sand is finer than 1/8".
Why sort it? Why not just leave it all mixed? The accumulations in the wash are not uniform.
One dam catches finer stuff than another, and even parts of the trapped aggregate are different behind the same
Sorting is helpful for several reasons. When I need only sand, as for making the rainwater
catchments and stucco, I can use sand. Measuring for concrete is more precise when I know how much sand I have. For
casting blocks and pavers, I can use sand and fine aggregate and leave out the bigger gravel.
The sand/gravel project is covered on a DVD.