Monitoring Surface Runoff in Stormwater Management

Rain supplies moisture that nurtures plant and animal life. Natural precipitation fills water reservoirs so that human residents can have everyday lives. However, as rainwater flows through the landscape, it can cause erosion, flooding, and water damage. Intentional stormwater management must also incorporate plans for surface runoff.

What Is Surface Runoff?

In a short sprinkle, the ground absorbs most of the precipitation. However, during sustained rainfall, the earth becomes saturated. When rain can no longer soak into the ground, it begins to flow on the surface. Gravity exerts its pull on the liquid, and it follows the most accessible path downward. Eventually, surface runoff makes its way to a water source, such as a creek or river. In northern climates, the spring thaw will also lead to runoff. As the temperatures rise above freezing, melting ice and snow increase the water levels of rivers, lakes, and other reservoirs.

Water Running Through the Natural Water Cycle

Water running on the surface is a normal part of the water cycle. About two-thirds of the precipitation either soaks into the ground or evaporates into the air in heavy rain—the final third flows as surface runoff. The water into the earth also flows slowly underground. Some will nourish plant life, but more will make its way into aquifers and the water table. Because water flows slower beneath the ground, heavy rains will cause gradual increases in river and stream levels.

Runoff over the Human Landscape

Cities and towns provide a challenge for stormwater management. Much of the urban landscape consists of impervious surfaces like rooftops, roads, and sidewalks. The portion of rainwater that would generally soak into the ground also flows as runoff. This additional volume can cause flash floods when waterways rise unexpectedly.

Pollution and water quality are additional concerns when runoff flows through the human landscape. The flowing water picks up non-biodegradable debris like plastics. The water washes petroleum products from streets and into stormwater drains. When water flows over agricultural areas, it can pick up pesticides and fertilizers. These impurities result in algae blooms and other water quality issues in lakes and bays.

Water Quality and Stormwater Management

As climate change affects rain patterns, some areas struggle with too little water and others with far too much. Municipalities must examine how they will address stormwater in their communities. These strategies should consider both increased water volume and water quality.

In many areas, rainwater drainage systems have emptied into natural water resources without any filtering or treatment. However, engineers are developing new techniques that both slow the flow of runoff and remove some impurities.

At a basic level, these solutions include filters and screens that remove larger debris from runoff. Other possibilities mimic the natural process of water flow. Some cities are incorporating green spaces like artificial wetlands and rooftop gardens. In other areas, retaining ponds slow the water flow while letting impurities settle out.

How a Remote Monitoring Solution Can Help

Because water running during a storm can be unpredictable, water management systems must monitor the situation in real time. SCADA technology allows remote monitoring of the entire system. A SCADA system consists of sensors that let managers observe what is happening over a broad area. In rainwater management, the system can provide alerts about volume changes and performance.

SCADA systems also allow operators to control parts of the system remotely. With this resource, a water utility can address issues before they become critical. They can manage the flow to prevent flooding. The sensors give information about individual parts of the whole operation. This knowledge provides insight into which strategies are most effective in mitigating stormwater levels.

A Cloud-Based SCADA Partner

At High Tide Technologies, we specialize in cloud-based SCADA technology for municipal water collection, treatment, and distribution systems. As cities expand and storm patterns change, stormwater drainage strategies must change with them. A SCADA system is a remote monitoring solution that can improve the efficiency and safety of your stormwater management system.