Water Tanks

Why?

3000 gallon black poly water tank.

Unquestionably clean water is the most important resource for a sustainable existence in any environment. Historic weather patterns seem to be changing and can no longer be counted on, the rains may or may not come.

The first priority for rural survival is to secure a water supply. Here in the Northwest, snow pack in the mountains has been diminishing yearly while summers getting hotter and drier at record pace. From mid June to late October it rained only once, a paltry one tenth of an inch that did nothing but make pock mark indentations in the dry flour like soil. The woods were tinder dry and news of wild fires on TV were making everyone nervous. The regional hay crop was devastated from the lack of rain causing acute shortages and sending hay prices soaring. By the beginning of December we were 15" below normal precipitation for the year.

Miraculously these unhappy turn of events were interdicted by the emergence of the La Nina climate event. Her colder and wetter than normal winter for the Pacific Northwest made up 9" of the shortfall in three weeks. A train of Pacific storm systems lined up and swooped through one after another. The annual total was still more than 6" from the average but without La Nina it would have been an all time record dry year.

These events underscore the fickle and precarious nature of weather. If the La Nina event did not occur and the pattern of diminishing snow pack held course we would most likely be in dire straits with water shortages come next summer. Water storage is the solution to avoid being forced to take a bad gamble of rolling the dice and hoping for rain.

The problem with water around here is that it has a tendency to not stick around for long. There is plenty of water in early spring but whether it is replenished when most needed in summer is problematic, as evidenced by our small creek that we estimate millions of gallons roaring through during early spring and barely moving by end of summer. Capturing and storing a tiny fraction of this bounty in the spring would ensure an adequate water supply for the year whether the rains come or not.

400 gallon poly tank. Part of my neighbor's domestic water system.

The water requirement for rural survival should not only cover daily potable water usage but also irrigation needs, enough water for vegetable gardens, herb gardens, fruit trees, greenhouse, animal needs and hopefully some for spot fire suppression if needed. A large enough storage tank 2000 gallons or more would work well if used frugally and replenished after each use. I use a 3000 gallon tank and various other smaller capacity tanks strategically placed near gardens for easy use. I find cattle troughs very handy for garden use. The open top makes it easy to get a quick 5 gallons with a bucket or washing dirt off carrots by swishing them in the water instead of turning on a faucet. Another convenience is that you can get water to anywhere a hose will reach by throwing in a submersible pump. All the tanks and troughs are replenished with water from a hand dug well and a centrifugal pump. The well is 600' away but is set up to turn on when I flip a lever near the tank. Eventually the goal is to set up a solar panel system for continuous slow pumping during the day.

Portable poly tank 325 gallons. Made for pickup trucks. Used to water a small vegetable garden.

175 gallon oval and 400 gallon circular cattle troughs. Used to water a small vegetable garden and refilled daily.

In most cases domestic water supply is not recommended for irrigation purposes. We have a drilled well and the driller advised us against using it for irrigation. They cited possible over drawing of the water in the well casing and damage to the submersible pump. It should be OK if the well produces substantially more water than the pump can pump. Even so since ground water levels are independent of surface conditions and is next to impossible to gauge accurately, it would not be worth the risk of over use and running the well dry. Imagine the stress and hassle of having no water when you need it the most and frantically repairing or replacing a pump.

Old time rainwater storage container called a water butt.

The easiest way to capture water is to collect rainwater. 1 inch of rain on 1 sq' flat surface produce about 0.62 gallons of water. 1" of rain on a roof area of 20'x40' gives about 500 gallons of water. Significant amounts of water can be collected in just one good rainfall if roof areas of a house, barn, garage, shop, greenhouse etc are utilized. According to government studies one inch of rain falling on 1 acre of ground is equal to about 27,154 gallons.

"Irrigation of the land with seawater desalinated by fusion power is ancient. It's called 'rain'." Michael McClary

Water from a surface source however small can be continuously fed to a holding tank from where it can be pumped to storage tanks on demand. I have a large culvert pipe, 7 feet diameter and 11 feet in height, which I plan to burry below a small spring for a 3000 gallon plus holding tank and set up a solar pumping system as shown here.

Our irrigation requirement conservatively is about 200 gallons a day or 30,000 gallons for the season from May to September. My eventual goal is to have an irrigation water storage capacity of 10,000 gallons which is continuously trickle filled and topped off. That should allow for future garden expansions and be ready for possible hotter and drier summers.

2500 gallon poly water tank.

3000 gallon steel culvert water tank

Ideally one should estimate the total water need and double it, as building contractors do with their labor estimates, to ensure coverage of unseen scenarios. The constraint with this idea of-course is the cost.

The cheapest and easiest to setup large water tank I have found runs about $880.00 for a 3000 gallon polyethylene or poly tank which works out to roughly $0.30 per gallon, a very reasonable cost considering its importance.

These are above ground, free standing tanks plumbed for inlet and outlet hookups and an inspection manhole with a lid. The polyethylene is UV rays stabilized, weather proof and meets the NFS standard for potable water. Although weatherproof, in the northern latitudes the tank would need to be protected from freezing. My idea on this is to erect a straw bale structure over it.

Building a water tank, say out of concrete, would have been cost effective perhaps fifteen years ago. However today's price for steel rebar, plywood and lumber for forms and concrete combined with the price of diesel needed for excavation and delivery at or near record highs make it cost prohibitive. This is not counting the labor cost whether contracting it out or building it yourself.

10,000 gallons may seem like a lot of water but it really isn't, when one considers that the average water usage per person nationwide is 70-80 gallons a day or a household of 4 at over 9000 gallons a month not including watering lawns and washing cars.

Old railroad water tank from Utah.

Rusty old water tank from the Southwest.

Water tank from the Outbacks of Australia.