Monday, January 27, 2014

Update On Our Rainwater Catchment System

We have now had our rain water collection system for a year and a half 
and it is time to give an update on how we are using it.

This is a continuation of the post I did over a year ago that you can access at
Designing And Installing A Rainwater Catchment System.

The first year was a bit frustrating as we were in what the National Weather Service 
describes as an "exceptional drought" which is their highest category.
It is hard to store water when there is no rain.
This relates to the topic of how to best size a rain water collection system.
When it is possible to go for more than six months with less than an inch of rain,
 a larger system may be necessary.

The first winter two of four valves cracked from freezing 
as the bales of straw on them were not enough to keep them from freezing.
 We had been advised to simply lay the straw on top of the valves from the supplier.

We came up with two solutions.
 Starting with the photo above you can see the bale of straw as it was,
but now we have an extra layer of protection as shown in the photo below.

What we came up with was to carve out two pieces of rigid foam insulation to fit over the valve,
in this case we used scraps of extruded polystyrene or "blue board and pink board".
It is always handy to save scraps from projects.

Allison cut out the foam (above) and I made a simple wrap around of sheet metal 
that I screwed together which holds the foam on to the valve.
A bit crude but it works quite easily,
 and is easy to get to the valve on warm winter days when we need water.

It only takes a minute to remove the straw that we still use on top,
slide off the metal, and hook up a hose.

In the lower right corner in the above photo you may notice the black 2" ABS overflow pipe
 peaking out from the straw and stone. 

This particular pipe froze back in December as snowmelt overflowed from the tank
but always allowed water through and thankfully never cracked the ABS.

This brings up the importance of directing your overflow rain water
 to where you can use it and it won't create problems.
 Each tank has a shallow trench that directs water well away from the tank 
and house and to areas where we can use that water, mainly trees.
 There can be a lot of water in a heavy rain or snowmelt.

The one shown starting above is filled with various size stone creating a french drain 
as it directs water by two lilacs, an apple, a peach, a small maple 
and on to even a couple more trees.
Every climate and topography is different so be sure to consider the issue of overflow.

On the tank shown above I left the overflow pipe up higher 
to be able to put a 5 gallon bucket to catch overflow
 and it created quite a glacier but again it never became a problem.

This tank is partially shaded through the winter.

(We are in a USDA zone 6 with a normal low for the winter around -5 degrees(F.)+/-.)

We did have rain in September and snow in November that filled our 4 tanks full,
 so for the second solution I took the valves off of three tanks 
and used 3/4" galvanized plugs instead to get us through the winter.

I was worried about the water pressure in doing this procedure but it went smoothly.
Make sure you are prepared to quickly insert the plug as soon as the valve is removed,
including having teflon tape already wrapped on the plug.
Anyone with basic plumbing skills should be okay but be prepared.

A week ago I removed a plug, put in the valve to do some watering,
and then replaced the plug with little problem other than getting a bit wet.

The water pressure is strong but but not so strong that you can't insert the plug.
I lost maybe a couple of gallons of water during the process.

Above you can see the plug and the overflow pipe.

During the summer when we did have water we used gravity pressure with the hose.
I looked into pumps but I was never satisfied with the options. 
Pumps are prone to burning out
 and the best system of a pump with pressure tank seems a bit much in cost and labor.

My latest idea is to get another, smaller tank to put up on a hill about 8' to 10' higher
 and about 30' away and use a simple pump with a hose to fill that tank
 and use gravity from there. Hmm?