Managing Rainwater & Impervious Surfaces
When we develop cities we change the landscape, pave roads and parking lots and build structures with roofs. These impervious surfaces no longer allow rainwater to soak into the ground as it would in the natural environment. Rain water flows quickly off these hard surfaces and into our storm drain system, designed to move water quickly to our creeks, rivers and streams.
The effect on the stream is similar to that of turning a firehose on your garden for short periods of time! The result on our waterways devastates fish spawning beds and habitat for our aquatic plants and animals. The water quality also suffers due to the harmful effects of increased turbidity, which destabilizes water temperatures and reduces oxygen for plants and animals.
Property owners can take action by managing their rainwater and reducing their flow off site:
- Reduce the amount of water going into your storm drain.
- Direct water from downspouts into a properly designed rain barrel or rain garden.
- Replace impervious surfaces with grass, gravel or other permeable options.
- Retain and plant native trees, shrubs and grasses.
Rainwater Harvesting
Rainwater harvesting is the practice of collecting and storing rainwater for future use. At a minimum, rainwater harvesting systems are comprised of a catchment area, a conveyance system, and a storage tank. Systems can also include a pump, water treatment system and fixtures for the use of water. Depending on the design and level of water treatment and purification, harvested rainwater can be used for outdoor irrigation, domestic purposes, such as toilet flushing and laundry, and even potable uses.
When designing and installing rainwater harvesting systems, it is important to consider provincial codes, regulations and standards, as well as municipal codes.
Benefits of rainwater harvesting include:
- Supplementing municipal water demand: When larger volumes of water are collected it can contribute to lower municipal water bills.
- Reduction in the volume of water entering the stormwater system: Collecting rainwater helps to protect our watersheds, streams, creeks and the nearshore environment by reducing the volume of water entering the stormwater system.
- Recharge of ground water: Using harvesting rainwater for irrigation, or directing overflow into a rain garden will help to replenish groundwater stores.