Collecting & Storing Water for Your Yard

If you're trying to conserve water for your yard and garden, it's worth looking into the various ways you can grab and save this precious resource — thereby not having to turn on the house spigot.

Water collection is easy, convenient, affordable … and smart. The two main options are rain barrels and cisterns. You may hear these projects referred to as rainwater harvesting.

The main source of water is rainwater routed from your home’s gutter system, so you want good gutter coverage of your rooflines, complete with screens or filters. Make a practice of cleaning out the gutters yearly, ideally in a dry season (because it’s easier).

Other possible sources include runoff from other impervious hardscape in your home landscape, such as an elevated patio or deck where you can route and collect that runoff.

Before proceeding, find out if the government in your area has limitations — that is, limits on how much water you can collect from your own home and landscape. Colorado’s regulations are a case in point. Presently, most homeowners in that state are limited to a maximum of two rain barrels with a combined maximum storage capacity of 110 gallons. Permitting may apply.

You might want to check whether there are local tax incentives, rebates, or discounted equipment suppliers. Many municipalities offer incentives to encourage water conservation and stormwater control in their communities.

Rain barrels

Not all rain barrels are created equal — they’re usually made of some kind of heavy-duty plastic; some are larger, some are smaller. Colors and styles, as well as capacity, varies. Household barrels are typically 50 gallons (though larger ones are available). They range in price from about $100 to $400. Look around at what your neighbors are using and shop around locally and online to locate the many choices.

You get what you pay for. The best rain barrels are made of UV-resistant resin, with seamless rotational molding and spin weld fittings. They aren’t cheap, but they’re long-lasting and work beautifully.

You can also make your own rain barrel. Use a large, clean, sturdy plastic barrel and install a lid (with an opening for the incoming gutter water) and spigot. Heed the following information — features that good, purchased rain barrels should also have. Figure 2-2 shows a good example of a rain barrel.

Unless your area is fortunate enough to receive regular rainfall (uncertain or unlikely, to be honest, for most households in water-scarce areas), rainwater collection isn’t a dependable or year-round source of water for your home landscape. Consider it supplemental and, of course, make the most of it.

Recycled barrels may be tempting, but you must find out what the original use was; solvents, oils, and farm chemicals are all no-nos. Old garbage cans may be leaky or not strong enough to support a full volume of water without buckling.

Seeking certain features

Rain barrels work best when they have the following practical features:

• A sealable lid: A securely fitted lid keeps out debris, bugs (including mosquito larvae, definitely unwelcome), and animals (including birds and snakes). Screening may not be sufficient because pollen and dust can still get through (and if the water will be directed into an irrigation system, tiny materials like those items can clog emitters). Use a solid lid such as a board, piece of metal, or plastic. A good, non-flimsy, secured cover is also a safety matter, if you have a curious outdoor cat on the premises or small children playing outdoors.
• Outlet spigot: It needs to sit low-down on the side of the barrel. Otherwise water sits below it and becomes stagnant.
• Overflow pipe: When a barrel gets really full, it will overflow. A pipe inserted near the top can carry off excess water — it should be long enough to be routed to a nearby plant or bed. Thus no water is lost or wasted!
• Sturdy construction and fittings: These prevent leaks.

Some store-bought ones come with a flat side/flat back, making it easier to wedge against a wall of your house — a nice option.

Installing your rain barrel

When you install your rain barrel, remember these pointers:

• Place your rain barrel on an ample and level spot, ideally a concrete pad or pavers.
• If you can elevate it, gravity will help with water pressure. (However, not too high — you don’t want it to topple.)
• Site it in a spot that’s handy to your garden and plants.
• Make sure the spot is comfortable and accessible for you (checking on it, hooking up a hose, filling a watering can, and occasionally cleaning it).
• Route a downspout or downspouts into it; add a filter/filters if there’s the potential for lots of debris.
• Consider multiple barrels because if all downspouts lead to just one barrel you have the potential for overflow/wasted water.

Using the water from your rain barrel

When you’re ready to use the water in your barrel in your yard, keep the following in mind:

• You can hook up a hose to the spigot.
• You can simply fill a watering can at the spigot and make repeated trips into the garden or to your potted plant collection.
• You can even hook up an inground irrigation system to it

Don’t hook up a soaker hose to a rain barrel’s spigot. There isn’t enough water pressure for the soaker hose to operate effectively, particularly at its farthest reaches.

Maintaining your rain barrel

Clean out your rain barrel and perhaps replace the spigot, and any filters, once or twice a year. Otherwise silt may build up in the bottom, and/or the interior may get a stinky film.

If your winters have freezing weather, completely empty the barrel beforehand. Freezing water in a spigot can ruin it, and residual water in a frozen barrel expands and can damage it. Store it in a garage, shed, or barn over the winter months.

Water that runs off your roof, into your gutters, and then into your rain barrel is untreated and may pick up chemicals and debris from your roofing material. It may also be contaminated by anything from bird droppings to microbes, or contain impurities absorbed from the air, such as arsenic and mercury. Even if you have filters in place or flush off the first few collected gallons, don’t drink it. Only use this water on your plants and lawn!

Supplemental water for your rain barrel

What if there’s a period of no rain? Your rain barrel stands empty and unused, which is unfortunate.

You can supply it with household water, then. Collect kitchen-sink water, veggie-rinsing water, bathtub/shower water, even dehumidifier water. Avoid water that has particles in it or soaps that may contain microbeads. Use pitchers or buckets in the house, and once they’re full, make a delivery to the rain barrel, replacing the lid afterward.

Cisterns and tanks

Cisterns are large tanks for storing as much as 20,000 gallons (75,708 liters) of water. Many farmers and market gardeners, as well as public parks and gardens, use such things, but residential homeowners can use cisterns to stockpile water for later use, too.

A homeowner-size cistern is about 10 feet by 20 feet and 3 feet deep (3 x 6.1 and 0.9 m), with a capacity of around 4,000 gallons (15,141 liters).

Check with your local authorities to see if cistern use is permitted or regulated in any way. Areas with severe water restrictions ban these.

If you do get the green light, new challenges lie ahead, including location, materials, cost, delivery, and setup. You also want to consider how you can protect it from heat and sun (overheated water or algae growth being the problems) and what types of filters and pumps to use, if any. If you’re determined to proceed, consult the supplier — whether a home-improvement store or an ag-supply outlet.

Other ideas

Water directed from downspouts from your roof, or an upper deck or balcony area, and routed directly into your garden can bring needed water to your plants — assuming it rains. Although this isn’t a viable year-round watering strategy, it’s safe and legal.

You may want to consider a rain garden. Chapter 16 discusses rain gardens in greater detail.

Another option is a relatively new technology called rain walls. They’re basically slender vertical water-storage tanks, made of strong, UV-stabilized, food-grade plastic. Pioneered in Australia, they come in building blocks, so they're stackable or can be set up as interlocking forms. You can fit one or more into a very narrow side yard, for example, or make a fence or wall out of several or many. Installation is straightforward. One example of these is Rainwater Hog.

Is using gray water a good idea?

Gray water (sometimes spelled “grey”) may be another source of water you can collect and give to your landscape plants. Gray water is water from inside your home, basically anything but toilet-flushed water bound for the sewer or septic tank. Also avoid collecting utility-sink water. Gray water is wastewater from household sinks, showers and tubs, and laundry.

Utilizing it is, indeed, water-wise. You’ve paid for it once if you get your water from your municipality, yet you’re using it twice (for those with well water, similar point: you’re using it twice). Thus you’re conserving water and conserving energy. By not sending this wastewater into the sewer or your septic tank, you’re lightening their load, too.

There may be incentives to use it, or there may be restrictions. Check your city, county, or state websites and/or confirm with phone calls before proceeding.

Here are the best ways to get it into your garden, where it’s needed:

• Collect in buckets and pitchers. Leave them in the tub and sinks at all times so everyone in the household gets in the habit of dumping gray water in them.
• Route directly. An outflow pipe from the kitchen sink or washing machine goes straight out to the yard.

An on-off valve is a good idea, for those days when you run three loads of wash, which may be too much water for your plants, especially if you’re growing drought-tolerant natives.

• Rig an irrigation system, complete with storage tank, filters, and outgoing lines. This sort of thing takes some expertise, and some municipalities don’t allow DIY installations; you must hire a trained and licensed professional to install it.

Because people use soap products in all of these areas, and some soaps are harmful to the environment (to soils, to plants, and to groundwater), find out what’s allowed and what’s best. Basically, you want to favor soap products that don’t contain microbeads, phosphates, salts, boron, or oils. You may have to change brands in order to collect maximum gray water. Also, use common sense: don’t reuse household water that contains bleach or cleaning products, or laundry water that rinsed diapers or a mechanic’s work clothes.

Out of an abundance of caution, don’t use gray water on certain plants, including anything you’ll eat — for example, salad greens and melons. However, watering tomato and pepper plants, berry plants, and trees (including fruit and nut trees) with gray water is considered okay.