8 Ways to Capture Rainwater in Your Garden
With the threat of El Niño upon us, strategies in place to capture rainwater in the garden will help divert the larger than expected amount of rainfall. Infiltration of water through the soil removes pollutants, recharges ground water and keeps contaminated water from entering the storm drains, but it does need to be properly controlled in order to prevent larger problems such as flooding and erosion.
Capturing water for reuse in the garden also lessens the need for irrigation which will in turn provide some relief on the monthly water bill.
Southern California residents wondering how best to divert and repurpose rainfall can consider these eight methods.
1. Rain Gutters
Older homes do not always have rain gutters installed, but they are a good idea to consider with heavy rains on the horizon. In fact, rain gutters are often overlooked in Southern California because we usually don’t receive an unbearable amount of rain.
Uncontrolled rain flow can lead to a variety of problems including flooded basements, rotten decks and erosion. Here, erosion is the most common problem. For example, several houses without rain gutters on Mount Soledad in La Jolla experienced mudslides during the heavy rains of 2005.
To give you an idea of how much water rain gutters can divert, the County of San Diego estimates that approximately 600 gallons of rainwater can be harvested from just one inch of rain falling on a 1,000 square foot roof.
2. Rain Barrels
We’ve covered rain barrels already but the still play a very important role in diverting rain water from the roof and into the garden.
Basically, rain gutters collect water that falls on the roof which is then diverted to ground level by downspouts. Normally, downspouts are connected to landscape drains that lead to stormwater drains and into the ocean. However, they can also be pointed to a dry creek or similar method of diverting water away from the house and into the groundwater supply.
In the case of rain barrels, water is diverted into a giant barrel via a downspout. Homeowners can then redistribute water from the barrel around the yard as needed. Check with local authorities to see if rebates are still available (right now they are $75 per barrel for San Diego residents).
Swales are flat-bottomed shallow drainage features that channel water to other places. They’re designed to slow the flow of water by letting it infiltrate into the soil along the way. Swales are most commonly lined with grass or soil. They often line driveways and sidewalks to capture run-off.
3. Dry Creek Bed
Dry creeks and swales often serve the same purpose and these terms are often used interchangeably. Dry creeks are intended to mimic the look of natural waterways after they dry up. They’re usually lined with rocks or gravel of varying sizes that should look like there were deposited into place by running water. Typically, a landscape fabric is applied before the rocks are laid in order to prevent the growth of weeds.
Tip: If planning a dry creek at home, it will look more natural when various sizes of rock are used. Many homeowners make the mistake of using a rocks of the same size… discerning nature enthusiasts will certainly be able to notice the difference.
4. Rain Chains
Popular in Japanese gardens, rain chains are alternatives to downspouts and divert water to the ground or into drains in a graceful, decorative manner. Most are constructed of copper and the water emits a lovely, soothing sound as it cascades down the chain.
Rain chains can be actual chain links or purchased in a cup version where little cups linked by the chain act as funnels to slow the flow of water. The cup style does splash a little so be mindful of locating them near doors and windows.
Dams can be created in a variety of places around the yard to trap or slow water in a particular area in order to allow it time to seep in and replenish the groundwater system. An ideal place for a dam is under a walkway bridge. Dams are also useful for filling dry ponds, mentioned below.
6. Dry Ponds
Some homeowners prefer to install dry ponds versus dry creeks. These are designed to fill with water after rainfall and are great options for small yards as they tend to take up less room. A small depression or basin (see below) is dug into the soil, lined with landscape fabric and rocks of varying sizes to mimic the look of a dried-up pond. Lining the pond’s perimeter with bigger rocks will both define the space and also help dam the water.
Basins are man-made depressions in the soil that are made to hold water and let it infiltrate into the soil. They’re located away from structures and water is somehow diverted into them. Basins are mostly a solution for homeowners with large properties and often look like a natural valley.
8. French Drains
French drains are brilliant for capturing water that would otherwise be freestanding. This eliminates the risk of mold and other undesirable effects from water pooling next to structures and hardscape. French drains are perforated pipes that are buried underground at a slight angle to divert water to its intended destination. A layer of gravel directs water from from ground level into the pipe.
This concept has been around for a while but homeowners are stepping french drains up to a new level of pretty. Guess what is below this strip of blue river rock? Yes, it’s a French drain.
How do you capture rainwater in your yard?
Top photo credit: daisy rain garden, Flickr/widnr;