Trees and plants slow down and filter runoff in areas with natural vegetation before it reaches surface water bodies. When it comes to stormwater management, urbanization is a double-edged sword.

Impervious surfaces that redirect water, such as concrete pavements and rooftops, interfere with natural drainage, evaporation and infiltration. As more areas in Australia experience heavier rainfall, homeowners should be vigilant about stormwater management to prevent avoidable water damage.

Let’s discuss the impact of stormwater runoff as we explore why proper management should be a priority.

What is Stormwater Made Up of?

Stormwater is snowmelt or rainfall that flows along the ground surface and drains into lakes, streams and storm sewers.

As the water flows over various surfaces, it collects debris and pollutants such as soil, sediments, leaves, grease, litter, chemical compounds and heavy metals like lead and zinc.

How is Storm Water Collected?

One effective way to manage stormwater is collecting excessive runoff to reduce water volume.

▪         Roof Water

You can harvest rainwater before it reaches the ground through gutter systems. Once you store the rainwater in tanks or reservoirs, you can use it within your home for flushing or outdoor activities such as pressure washing and irrigation.

▪         Surface Water

Another effective way to collect stormwater is through an infiltration basin. If your home rests on highly permeable soil, you can create a shallow basin to temporarily store stormwater runoff, allowing it to infiltrate the surrounding soil.

▪         Subsoil Water

Collecting subsoil water involves digging out an area with a natural depression that is typically dry during drier seasons. Such places temporarily store stormwater runoff to reduce the quantity and enhance the water quality since they allow sediments to settle.

Stormwater Impacts

▪         Source of Pollution

Stormwater runoff carries inorganic and organic matter into water bodies. These pollutants litter beaches and river banks with sanitary waste, often harboring disease-causing pathogens.

Chemicals from fertilizers and pesticides, heavy metals and ammonia are often toxic to high concentrations of aquatic life and human beings.

▪         Can Alter River Flows

The runoff volume and speed changes affect the physical characteristics of rivers, streams and ravines. The channels widen to accommodate the excess runoff, which can cause steeper banks to collapse as the runoff volume increases.

▪         Changes Flooding Patterns

Runoff from impervious surfaces flows faster, increasing the water volume and reducing natural groundwater flow. These changes often overwhelm water channels, causing the water to break the bank and flood areas that wouldn't typically flood.

▪         It affects the Availability of Water for Irrigation

Reduced water infiltration into the soil leads to lower underground water volumes. A drop in the water table reduces water availability, affecting irrigation, particularly during dry periods.

Tips to Manage Stormwater Runoff

▪         Limit the Use of Fertilizers and Pesticides

You can reduce the chemicals that seep into stormwater if you avoid applying fertilizers or lawn chemicals when the forecast predicts rainfall exceeding 13mm in the next 24 hours.

Ensure you carefully pesticide and fertilizer labels, apply the recommended amount and dispose of the empty containers correctly.

▪         Remove Leaves and Other Debris

Leaves and debris can clog your storm drainage system. Ensure you clear leaves and debris and dispose of them correctly or use them for compost manure.

▪         Keep Plants and Trees Maintained

You can minimize erosion by planting vegetation in bare areas and keeping well-maintained trees.

▪         Create a Rain Garden

A rain garden is a shallow depression that holds stormwater and runoff for short periods. You can plant decorative plants to liven your landscape.

▪         Get Your Stormwater Drains Inspected Regularly

Inadequate maintenance can hinder the water flow and damage your stormwater drainage system. Annual inspections help to identify weak points that can cause extensive damage to your home.

Stormwater management is vital to protect your home from water damage during heavy rains. Contact a licensed plumber to inspect your stormwater drains, remove accumulated debris, and repair damages.