Water Saved With Rain Gardens

By Author: Marie Wakefield
Total Articles: 13
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The indigenous soil and forests of many regions accumulate, sieve, and gradually release fresh, clean water to streams, wetlands, and estuaries. The varieties of life in marine and fresh water, as well as on land, require clean water to thrive.

As cities grow, they encroach upon and change natural settings; wild areas are replaced with infrastructure and other hard surfaces. During periods of precipitation, more water flows from these man-made surfaces than natural areas, carrying oil, fertilizers, pesticides, sediment and other pollutants downstream. In fact, much of the pollution in streams, wetlands and rivers now comes from storm-water (water flowing off developed areas). The increased volume of water and allied contaminants from developed land are detrimental to water resources and harming aquatic life.

One possible solution is a type of landscaping called the rain garden-
WHAT IS A RAIN GARDEN?
A rain garden functions like a native woodland by collecting, absorbing, and filtering storm-water runoff from manmade structures that don't allow water to soak in. Rain gardens are designed as low ...
... depressions that:
Can be formed and sized to fit your landscape.
Are constructed with soil mixtures that allow water to infuse quickly and support healthy plant growth.
Can be filled with a variety of plants to fit the environs.

Rain gardens are one of the most versatile and effective tools in a new approach to managing storm-water called low impact development (LID). An LID project may incorporate several tools to soak up rain water , reduce storm-water runoff , and filter pollutants. Some examples of these tools include permeable paving , compost-amended soils, vegetated roofs , rainwater collection systems and rain gardens.

Rain gardens offer numerous benefits, including:
Sieve oil and grease from driveways, pesticides and fertilizers from lawns, and other pollutants before they reach the storm drain and eventually the waterways.
Decrease flooding on adjacent areas, overflow in sewers, and erosion in creeks by absorbing water from impermeable surfaces.
Provide homes for beneficial insects and birds.
Augment the amount of water that soaks into the earth to recharge local groundwater.

Maintaining the rain garden
Rain gardens need maintenance just like any landscaping, to perform well and look good. However, a well-designed rain garden needs minimum care.

For the first two to three years most plants need deep watering during the dry season to establish healthy root systems. If you have selected the appropriate natives or plants, then the rain garden will need little or no watering after two or three years. However, watering may be necessary during prolonged dry periods even if plants are established. During these periods watch for signs of stress, such as wilting leaves.

Watering techniques for rain gardens include:
Soaker hoses: Soaker hoses save water and can be covered with mulch to save even more.
Sprinklers: Place tuna cans in a few locations around the rain garden and stop watering when there is 1 inch of water in the cans.

Mulching
Mulch prevents erosion, controls weeds, replenishes the organic material in the soil, and improves infiltration. Every year check the mulch layer and, if needed , add shredded or chipped hardwood or softwood to the sides and coarse compost to the bottom to maintain a layer that is about 2-3 inches thick. Mulch can be applied any time of the year, but assuring an adequate mulch layer for the dry summer and rainy winter months is particularly beneficial.

Weed regularly. A nicely prepared rain garden is a great place for invasive plants to start growing. This is where mulch comes in handy; it will be simple to just pull those little seedlings out before they get established. Excavate or pull weeds out by the roots before they go to seed.

Exposed soil and erosion
Sediment flowing into the rain garden can clog the soil mix and slow drainage. Sediment carried out of the rain garden can harm streams and wetlands in many ways, some of which include transporting pollutants, covering fish spawning areas , and filling in stream channels and pools. If erosion persists in the rain garden , too much water may be flowing into the garden too rapidly. In this case, the slope of the pipe or swale directing water to the garden or the amount of water may need to be reduced.

Remember, rain gardens can be an integral part of our storm-water management and environmental approach. Their use doesn't involve a lot of centralized planning. They don't require much space, can be fitted into oddball shapes, and can readily added to existing buildings. They look nice, and you don't need to be an engineer to build one. Anyone can make a rain garden -- including you!