Stormwater is a natural component of the hydrological cycle that moves and distributes water between water bodies, land and the atmosphere.
However, heavy rain or snowfall causes groundwater saturation, forcing excess water to flow on the surface and into ditches and sewers.
As a homeowner, you must manage stormwater and runoff to protect your home from irreversible water damage.
Let’s explore what stormwater is and why it matters to you.
What is Stormwater Made Up of?
Stormwater comes from water runoff on impervious surfaces such as rooftops and roads, collecting debris and pollutants such as rubbish, chemicals, leaves, oil, and soil.
How is Storm Water Collected?
Stormwater flows on impervious surfaces that prevent natural drainage into the soil or precipitation, such as:
▪ Roof Water
You can collect stormwater using gutters and downspouts that lead into storage containers. The water quality and quantity depend on the type of roofing material and your location.
▪ Surface Water
You can collect stormwater using surface or ground catchment areas. Ground catchment collects larger water volumes due to a larger surface area. This water helps to meet the water demand in dry seasons.
▪ Subsoil Water
Collecting stormwater in the subsoil is possible by digging out a depression. The runoff flows into the area, where it rests briefly before infiltrating the surrounding area.
Stormwater Impacts
▪ Source of Pollution
Stormwater flows along the ground surface, collecting pollutants, including:
- Grease and oil from roads
- Heavy metals such as lead, copper and zinc
- Sediments and bacteria
- Garden waste and litter
Although some pollutants are harmless in small quantities, large water quantities in stormwater can lead to harmful levels.
▪ Can Alter River Flows
Increased stormwater changes the water flow patterns to coasts, rivers and creeks. Since there’s minimal infiltration into groundwater and soil and higher surface flow, more erosion along the water passages alters river flows.
▪ Changes Flooding Patterns
Impervious surfaces like roads and pavements increase the runoff volumes. These volumes peak during rainy seasons, causing severe floods in areas that typically don’t flood.
▪ It affects the Availability of Water for Irrigation
Stormwater runoff minimizes water infiltration into the soil, replenishing groundwater aquifers and reservoirs. This causes shallow groundwater during dry periods, reducing the water available for vital activities such as farming and irrigation.
Tips to Manage Stormwater Runoff
Although heavy rainfall and storms are beyond your control, there are several things you can do to manage the stormwater runoff, such as:
▪ Limit the Use of Fertilisers and Pesticides
Stormwater carries chemicals from pesticides and fertilizers into the ocean, creeks, ponds and lakes. These chemicals can kill aquatic species like fish or cause excessive growth of aquatic algae and plants.
By limiting the use of such chemicals, you can help protect natural water bodies.
▪ Remove Leaves and Other Debris
Blockages in stormwater drains often cause overflow that damages property. You can reduce this risk by removing debris like broken branches and leaves from your garden before the rains.
▪ Keep Plants and Trees Maintained
Vegetation slows down water droplets that land on loose soil, binds the soil particles, reduces surface runoff and catches sediments. Maintaining your trees and plants goes a long way in reducing erosion and pollution.
▪ Create a Rain Garden
A rain garden is a shallow ornamental garden that retains surface water for a short period.
The soil and plants in a well-designed rain garden ensure adequate evapotranspiration and infiltration while reducing pollution.
▪ Get Your Stormwater Drains Inspected Regularly
Clogged and damaged drains can quickly become plumbing disasters during heavy rains. The best way to ensure proper maintenance is to have a drainage professional inspect the stormwater infrastructure at least once annually.
By nature, stormwater is heavy and often uncontrolled. If you fail to maintain your stormwater system properly, the water will find weak points such as cracks or blockages, causing more extensive damage to your home.
Get your stormwater drains inspected ahead of time to protect your home during the rainy season.