The indigenous soil and woodlands of many regions store, sieve, and gradually release fresh, clean water to streams, wetlands, and estuaries. The rich multiplicity of life in marine and fresh water, as well as on land, requires clean water to flourish.
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 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 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.
If it doesn't rain , water your plants until they are established. Once the deep root system has grown into the soil,they will probably survive a drought. But until then, just like any newly planted perennials , they need water to get started.
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.
Break strong water flow. The area where water flows into your garden can , during strong storms , erode soil, mulch, and plants. A few strategically placed rocks, boulders, or stone dams in this area of strong water flow can break the force and prevent this from happening.
Don't let sediment, soil , sand, or debris flow into your rain garden. It can bury the plants, destroy the absorbency, and ruin all your efforts.
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!