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 human populations intrude and alter natural settings, native forests and soils are replaced with roads, rooftops and other hard surfaces. When it rains or snows, more water flows from these surfaces than undisturbed 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 added volume of water and associated contaminants from developed land are damaging 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 acts like a native forest by collecting, absorbing, and filtering storm-water runoff from roof tops, driveways, patios, and other areas that don’t allow water to soak in. Rain gardens are created as shallow depressions that:

Can be shaped and sized to fit your yard.

Are constructed with soil mixes that allow water to soak in rapidly and support healthy plant growth.

Can be landscaped with a variety of plants to fit the surroundings.

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 provide multiple benefits, including:

Filter oil and grease from driveways, pesticides and fertilizers from lawns, and other pollutants before they reach the storm drain and eventually streams, wetlands, lakes and marine waters.

Reduce flooding on neighboring property, overflow in sewers, and erosion in streams by absorbing water from impervious surfaces.

Provide habitat for beneficial insects and birds.

Increase the amount of water that soaks into the ground to recharge local groundwater.

Rain gardens are low maintenance, but not NO maintenance. You worked hard to create your rain garden, and to keep it working well for you and looking its best, some regular care is required.

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.

Mulch your rain garden. Check the mulch level every year , 2-3 inches of shredded hardwood mulch should be applied in the spring, or if bare areas appear, more often. Mulch keeps the garden moist and spongelike, ready to absorb rain. Mulch areas along the sides and bottom of the rain garden. This prevents a hardpan from developing on the surface of the garden. Mulch protects the plants in the garden as they get established and makes it easier to weed.

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!