During the summer months our water bill usually goes up 100$ a month due to extra watering of the yard and gardens. Extra water is needed because it is much hotter and it usually does not rain much during June, July and August. This summer when I expressed a desire to more than double the size of our vegetable garden, Garry was reluctant due to the extra water we would need, especially since the cost of water here had just gone up. We set ourselves a challenge to conserve water anyway we could.
The first thing we did was heavily mulch all flower and vegetable beds. The mulch was "free" from a dying tree we had cut down. This reduces the amount of water you need since it reduces evaporation. It also eliminates competition for water by suppressing weeds.
The next thing was to install three connected rain-barrels to the only rain-gutter we have on our property, which is on our detached garage. This is making use of available water that is normally lost to you as run off.
Two empty 55 gallon barrels cost $7.50 each, and the parts needed cost about 25-30$. So about 23$ each to make a rain-barrel is quite a bit of savings over a store bought ($150 each) barrel. The third barrel is actually just a trash can stuck under the over flow from the other two. This one is handy for dipping my watering cans into for hand watering.
The rain-barrels have spigots for filling a watering can or attaching a garden hose to. We only need about half an inch of rain to fill up these three barrels, and they are good for several waterings of the new vegetable garden.
The next thing I did for water conservation is to stop watering the Bermuda parts of my lawn. I continued to water a few shady spots that had Saint Augustine grass only when the grass actually wilted. St. Augustine really doesn't need a lot of water to keep it looking nice, since it grows in the shade, but Bermuda needs a lot of water to keep it green in the hot summertime. My lawn did not turn completely brown as I had feared. In fact it still look pretty green even with no water, and it didn't look any worse than any of my neighbor's lawns.
Another thing I was already doing was using soaker hoses in all my flower and vegetable beds. Soaker hoses use a lot less water than overhead sprinklers because overhead sprinklers loose a lot of water to evaporation, and they water the ground indiscriminately instead delivering water directly to the plants roots. Watering with overhead sprinklers encourages weeds and really is a big waste. I snake soaker hoses through my beds so that mostly only the plants get the water, and I cover them with mulch to further protect from evaporation.
Next I did some research on, just how much water does a plant really need? I found that with drip irrigation a tomato plant only needs two pints of water a week! (I'm not sure if this holds true in Texas heat or not, but it was still way less than I had imagined!) This tells me that most of the water we are pouring on our gardens is wasted to run off, evaporation and migration down deeper than the roots of the plant. What a plant needs is moisture kept close to its root zone.
Even though I had been using soaker hoses in all my gardens, I still had the idea that the entire bed needed to look wet, so I was turning the water on strong enough to get the entire bed good and soaked looking. I learned something very important from the rain-barrels. Rain-barrels have very little water pressure. When hooked up to the existing soaker hoses overnight (a 50 foot hose) they would only release about 5 gallons of water. The area directly under the hose was good and moist, but a foot away was completely dry (I'm talking bone dry and cracked) - and my garden plants loved it! I began watering my flower beds (most of which are out of reach of the rain barrels) with much lower water pressure, so that the bed itself still looked dry but the plants were happy.
I also did some research on sub-irrigation which is applying the water below the soil surface directly to the plant root zone. In many parts of the southern-hemisphere farmers water gardens with buried porous unglazed pots. Water seeps out of the porous pots very slowly and waters plants growing next to it. These pots are so efficient that they use 10 times less water than a soaker hose! The reason for this is that the buried pots keep the soil around them consistently moist. The water is not running along the ground where it evaporates and encourages weeds. It also seeps slowly enough that it does not flow down too deep for the plants to reach.
I made my own pots by plugging the bottom holes of existing clay flower pots I already had and buried then in the new part of the garden that had no soaker hose yet. Next to the pots I planted pumpkins and squashes. These plants are growing huge with only the water from the buried pots! I top off the water in the pots only a few times a week when the water goes down a few inches.
I also learned that wilting plants do not necessarily need water. If the reason that they are wilting is because it is over 100 degrees outside, and not because the ground is dry, then leave them alone. They will perk back up in the cool of the evening.
Using rain-barrels, soaker hoses and sub-irrigation is using water more wisely. Now for water recycling. Water recycling is taking water you have already used in your shower or laundry, and reusing it in your garden. We accomplished this by putting another 55 gallon barrel setup outside under the laundry room window, and running the exit hose from the washing machine out the laundry room window into the barrel. One load of laundry almost fills the barrel. Once this was accomplished I felt I had more water than I knew what to do with! I really only need the laundry water when it is not raining at all.
So how much water did we save? My wonderful Hubby has kept a spread sheet for the last couple of years that has the amount of water we use each month and the amount we paid each month. (Don't ask me why he would spend the time doing this - that's just the way he is. Lucky for me.) Last July, when I watered per the old way, was unseasonably cool. Only a few days were over 100 degrees for the whole summer. This July we had 100 plus temperatures for weeks at a time. Even though it was so much hotter, my vegetable garden was two thirds bigger, and we added a separate herb garden, we used almost exactly 4,000 gallons less water in one month! The actual amount we paid between the two Julys was only 5$ less for this one comparison month, but when you consider that the price of water had gone up for this year on all the water that we use for everything else (laundry, dishes, bathing) in addition to what we used for the garden, then we saved quite a bit more.
So, I expanded my gardens, learned a lot about water, and saved money!