It is difficult thinking up really good titles for posts. If the title doesn’t explain things this will. This post is about how to irrigate your garden or water your plants without taxing one of our most precious resources.
First off I have to say that using fresh drinking quality water to water your lawn/grass is in my opinion a big waste. I am not saying you cannot have grass. We have grass in our yard. We have more grass than I would like, but it came with the house and it is hard to get rid of. We do not irrigate our lawn. It turns brown in the winter and occasionally in the spring when there is no rain, like right now. It has not rained for over two weeks where I live. So consider where you live, how much rainfall you get and what kind of ground cover is best suited to your region. Sometimes, rocks are the best ground cover.
If you just have to have a lawn that needs irrigation then the least you should do is have a grey-water system installed. All the water from your shower, bath and laundry can be diverted to a tank to water your grass. Some municipalities even offer this as an option to hook up to. If you cannot hook up to a grey-water system and you do have a sprinkler system, then use it to its fullest potential. Do not water when it is raining. Water only once a week. Test your system to see how long it takes to fill a tuna can with one inch of water. Only run the system for that long each week. Many people over water their lawns. Use less or no fertilizer and leave your grass long, say 3 inches tall to keep it lush and healthy. It retains the moisture better that way.
If you have a garden, be water wise. Know how often you need to water. Know which plants need more water. Also, water at the right time of day. Our utility prohibits watering from 10AM to 4PM. This is when the water is most likely to evaporate the fastest. Overhead sprinkling is probably the most inefficient method. A lot of the water can be lost into the dry air. Here are some articles on watering. http://www.doityourself.com/scat/watering
Prepare your soil at the beginning of the season to hold the water longer. Mulch the surface of the beds to help retain the moisture. Using drip irrigation or soaker hoses uses up to 50% less water than overhead sprinklers. Drip irrigation can be specifically designed to water each plant as opposed to the whole garden which would include the paths. Unless your paths are a walkable ground cover, they don’t need watering. Here is a great article on using grey-water in your vegetable garden. http://www.umassgreeninfo.org/fact_sheets/plant_culture/gray_water_for_gardens.html
The biggest take home message I got from that article is don’t water root crops or leafy greens with grey-water. Also rotate between grey and fresh. There are guidelines on how much to use and what not to put into the water to begin with.
No matter how much rainwater you get annually, I think a rain barrel is a fantastic idea. There are plenty of places to buy really expensive ones or you can make one fairly cheaply. This site http://www.cityfarmer.org/rainbarrel72.html has a wealth of information on rainwater collection, rain barrels and irrigation. We have several rain barrels that we use for irrigation as well as toilet flushing. Rainwater also is excellent for washing hair and clothing since it is naturally soft.
Above is our rainwater collection system we currently use in the garden. We have a 26′ x 12′ shed with a metal and plastic roof. The rain gutter catches the water and diverts it to the first barrel. My brilliant husband figured out that the water would automatically syphon from one barrel to the next with a piece of garden hose that reaches from the bottom of one barrel to the bottom of the next. The hoses have to be filled with water, pinched off in the middle then shoved quickly into each barrel. Takes two people. Also the barrels have to have and maintain enough water to keep the ends of the hoses covered with water, otherwise the syphon action is disrupted. We did it this way because for the short term it was easier than connecting all the barrels together and elevating them to drain one into another. The last barrel is an open garbage can for dipping my watering can into.
These are pictures of rainwater collection up near the house. My daughter is transferring water from a full container into empty ones. She has a lot of fun doing this. We try to collect as much water as we possibly can since this time of year can be very dry. You do have to watch the barrels for mosquito larvae and empty those barrels sooner or use a net to scoop them out and feed them to your fish. Covering the container can prevent the mosquito from laying her eggs in the water in the first place.