Water - Watch It or Lose It
by Doug Pushard
There are many ways to save water — conservation, passive rainwater catchment, onsite recycling (i.e., greywater) and active rainwater catchment. All of these methods require that you actively manage your water use, as opposed to just paying your bill each month and not thinking about how much water you use. Even with the easiest method, conservation, you still need to understand your water use to make intelligent decisions about how to conserve.
Becoming informed about your water use and making smart decisions based on that information is at the heart of what is called Active Water Management. If you want to save water, save money, help the environment, or live more simply — or all of the above! — then Active Water Management will help you achieve your goals
How much water do you use? How much do you really need? How can you conserve water? How can you optimize what you capture? These are a few of the questions you’ll consider as you develop your Active Water Management strategy.
Active Water Management helps you evaluate the various systems available and determine the best design for you. Start by determining how much water you use. This information is readily available on your water bill, or, if you are on a well, by installing an inexpensive water meter and tracking water use over time.
Once you know how much water you use, then start conserving. Start conserving indoors, as that is where most water is consumed and it’s also the quickest and easiest place to see results. There are a myriad ways to conserve (see Related Links on this topic) and they can be simple and inexpensive, too. (Some people even find conservation fun, but that is a different topic entirely.)
Once you have explored ways to save, move on to reusing water. How can you reuse/recycle the water you’re already consuming? The solutions can range from simple (capturing dishwater and bath water and reusing in the garden) to more complex and expensive (installing a greywater system or a faucet-to-toilet recycling system). Conserving water is a great way to save, but using water twice or three times is even better!
Once you have finished indoors it’s time to move outdoors. Even though in Santa Fe we irrigate our gardens and landscaping for just a few short months, outdoor irrigation is guestimated to be about 40 percent of our annual water usage. In drier areas (e.g., Albuquerque, Phoenix, Las Vegas, etc.) irrigation can account for well over 50 percent of total water usage. The EPA estimates that more than 7.8 billion gallons are used for irrigation annually, and that the amount of water used by a household outdoors in the summer can exceed the amount used for all other purposes for the entire year.
Start as you did indoors. Figure out how much water you use outdoors by examining your water bill, getting a water audit or installing an inexpensive water meter to track your outdoor usage. On your water bill, look at the difference between your winter and summer usage to determine how many gallons you use outdoors during the watering months. The following simple formula is appropriate given the watering months in Santa Fe:
1. Add November – March water use (in gallons).
2. Add May – September water use (in gallons).
3. Subtract the winter use from the summer use and divide the difference by five to determine how much additional water you use on average each month during the watering months.)
Now that you know approximately how much you use, start looking at where it goes. Do you have the appropriate plants for your locale or do you have plants requiring too much water or too much fertilizing and tending for our area? Can you replace some of your high water use plants with lower water use plants? There are many great books, local professionals and resources to assist you with this exercise (see Related Links).
Once you have studied how you are using the water, move on to managing it in the best possible way to minimize water use. Do you have enough mulch? Is your soil amended to retain water? Can you use more shade to cool your garden and house? Take advantage of the books, professionals and resources available to help you (see Related Links).
And how about that free water that falls from the sky? Are you managing it? Apply this quick and easy formula to figure out how many gallons of rain you get annually:
Lot size (ft2) x annual rainfall (inches) x 0.623 (gallons/ft3) = gallons you can easily capture
For example, if your lot is 10,000 square feet and you get 10 inches of rain per year, thats over 62,000 gallons of rainwater (10000 * 10 * 0.623). Once you have done this calculation for your lot, do the same math for your roof. If your roof is 2,200 square feet, you’ll get about 17,800 gallons a year (2,200 * 13 * 0.623). This last calculation estimates the maximum you could harvest and store if you were so inclined (see Online Calculators)
This number might surprise you. I know it did me when I started harvesting rainwater. And this is free water!
Now that you know how much water you receive, the next step is to make sure none of it leaves your property. You can achieve this through berms, swales, barrels or retention/infiltration ponds, or ideally a combination of these methods. Brad Lancaster’s book Rainwater Harvesting for Drylands and Beyond is an excellent resource for passive rainwater catchment.
A major benefit of using all your rainwater on site is that by reducing your stormwater runoff, you reduce your taxes. By taking water off the streets you reduce the need for stormwater system upgrades and therefore bond issues and tax increases. If everyone captured most of what fell on their property there would be very little stormwater runoff and little wasted water.
Once you have figured out ways to retain the water on site, it may be necessary to move to active rainwater catchment whereby you capture rainwater with above ground and below ground tanks. Below ground storage enables year-round capture in freezing climates, whereas above ground tanks in freezing climates always run the risk of freezing valves and/or busting expensive tanks.
For those who desire to capture as much rainwater as possible yet don’t want to spend a ton of money, a combination of above and below ground cisterns is the optimal solution. The below ground system is sized to capture only winter precipitation so the tanks can be smaller and consequently less expensive than if sized for the entire year. (Buried tanks are typically 30-40 percent more expensive than above ground tanks due to heavier construction.) Below ground tanks can be augmented with above ground tanks that are kept empty during the very cold months yet used the rest of the year.
Typically in these hybrid systems the rainwater drains automatically into the below ground tank and not the above ground ones. All the tanks are interconnected so that the above ground tanks drain to the below ground tank and the below ground tank can pump to the above ground tanks
As spring, summer and fall storms approach, water is pumped out of the below ground tank into the above ground tanks, allowing ample room in the below ground tank for incoming rains. The water levels in the above and below ground tanks must be monitored and actively managed to optimize rainwater harvesting.
With this hybrid approach it is possible to capture water year round without worrying about freezing valves, pumps or tanks — and your system can be as big as you need without busting the bank. It combines the benefits of below ground and above ground systems and is less expensive and easier to install than a total, below ground system. The catch is that it requires active participation of the homeowner to monitor and manage the water levels in the tanks.
Two such water devotees are Fred Nugent and his wife Yasuyo, who actively manage their combination water system (i.e. above ground, below ground, active harvesting and passive harvesting). In a normal winter, the below ground tanks are full with winter precipitation. In the early spring, as the threat of hard freezes has passed, they start moving water to the above ground tanks. As our normal late, wet, winter storms move through, they are able to capture this moisture and hold it until the irrigation season begins.
When the summer monsoons approach, they pump any remaining water out of the below ground tank into the above ground tanks so they have a ready reservoir to capture any and all the rain that may fall.
This active approach maximizes the water stored and minimizes costs. A side benefit is that they are extremely aware how much water they use and how much they have available for their garden. Fred says, “My wife and I believe that conservation of all natural resources is an individual and serious responsibility. Prior to moving to Santa Fe, we had never lived in a place where an adequate water supply was an ongoing concern. Now that we have acclimated to desert living, water conservation has become the ‘new normal’ for us. Harvesting rainwater in Santa Fe is an obvious, logical, and efficient extension of our overall conservation philosophy.”
Fred continues, “We actively manage our rainwater catchment system through both underground (1,100 gallons) and above ground (300 gallons) storage tanks. The rainwater is initially captured in the underground tanks. When those tanks reach approximately 80 – 85 percent of capacity (monitored by an in-tank gauge) we pump water to the above ground tanks. This transfer process is very simple and only takes a few minutes to initiate. We primarily use this stored water (through a drip irrigation system) for our vegetable garden that naturally thrives on the untreated rainwater. During the milder, drier winter months we use the rainwater and snowmelt to water our landscape.
“We believe that our system is a win-win solution. Not only are our plants receiving natural, unchlorinated water, but we are making our individual contribution to a worthwhile, and much needed, water conservation program.”
The suggestions made in this article can seem overwhelming and they can be if started all at once. Instead, think of it as a far ranging, life-long project during those thing that will help you will use less water and energy over time, not more.
How low can you go? Start in the areas that interest you and procrastinate in the areas that seem hard or uninteresting. The important thing is to start. Know how much water you use and then start saving today! You will save water and money and the planet. And what could be better than that?