Raingardens are one of the best landscaping design ideas to come out of Melbourne’s recent drought and water shortage conditions. With more ideas like these, the health of Melbourne’s rivers and creeks is guaranteed to improve.
Why is stormwater such a problem for our rivers and creeks
Each year about 500 billion litres of stormwater is washed off our roofs, driveways and roads when it rains. This stormwater contains many harmful pollutants such as oil, litter, animal droppings, organic matter, nitrogen and phosphorus, and it enters our rivers, creeks and bays untreated via stormwater drains.
Pollution such as nitrogen can cause excessive growth of algae, which leads to reduced oxygen levels in the water. Algal blooms threaten animals, plants and fish living in our rivers and creeks.
Roof water, particularly in an urban environment, is known to contain a range of pollutants. Some of these include heavy metals (such as zinc, lead, copper and cadmium). Other pollutants include phosphorus and sediments such as dust, dirt and animal droppings. Many of these pollutants are harmful to human health and to our rivers and creeks.
The amount and rate of stormwater entering our rivers and creeks after heavy rainfall can also be a problem, leading to erosion of river beds and banks and unfavourable conditions for many plant and animal species.
Benefits of building your own raingarden
There are many benefits for both you and the environment of building a raingarden in your own backyard.
are self watering and easy to maintain
are water saving, especially if planted with native, drought tolerant plants
help to filter stormwater before it enters our rivers and creeks
use a special soil called filter media, such as loamy sand, which will drain quickly and not release nutrients into the stormwater
help to reduce the rate and amount of stormwater that enters rivers and creeks after heavy rain
can make a real difference to the environment and contribute to healthy waterways.