What Stormwater Monitoring Solution is Right for You?

Stormwater monitoring solutions can help managers protect communities and the environment from the unpredictability of storms. Take control with a YSI Stormwater Solution.

• Round-the-clock visibility of water level and flow throughout a network
• Detection of point and non-point source pollution, as well as pollutant source-tracking
• 24/7 notifications when water levels or contaminants reach an actionable level
• Long-term decisions intelligence that leads to model-based predictions, especially for CSO prevention

What is Stormwater?

In rural environments, rainfall infiltrates into the ground. With heavy rainfall, there is either not enough time for infiltration to occur, or the ground becomes saturated with water. The excess floods low-lying areas and swells the adjacent creeks, tributaries, and rivers. Even seasonal snow and ice melt after a winter of heavy precipitation can lead to excess water running off into streams, rivers, and lakes.

In cities and other human-engineered spaces, such as airports and refineries, paved surfaces and rooftops are impervious to rainfall, which collects rapidly and flows into gutters and drains. Drainage systems deliver the excess water directly to rivers and waterways that are almost always adjacent to cities.

Coastal regions, ports and harbors are often the ultimate recipients of the runoff from both rural and urban environments. Increased urbanization and industrial activities along the world’s coastlines exacerbate the effect, and climate change is also driving more storm events along coastal areas.

In all cases, the excess water is referred to as stormwater and it is one of the most pressing issues of our time.

What Problems are Caused by Stormwater?

The problems caused by stormwater range from the very local to global scales. Examples of problems caused by stormwater are:

• Delivery of pollutants like motor oil, heavy metals, litter, and road salt from city streets, and deicers from airport tarmacs,
• Habitat damage due to erosion of river banks, and sedimentation as soils are delivered downstream,
• Delivery of nutrients and pesticides from agricultural regions, leading to eutrophication and destruction of wildlife and aquatic plants,
• Combined sewer overflows from urban areas that deliver both nutrients and potential pathogens into waterways,
• Roadway flooding that threatens driver safety, especially during an evacuation,
• Damage to infrastructure like bridges due to recurring high-flow events.

Some of the world’s biggest challenges are linked directly to stormwater. A notable example is the Gulf of Mexico "Dead Zone." Rivers that traverse large watersheds eventually deliver stormwater runoff into the ocean. The Mississippi River is a conduit into the Gulf of Mexico, joining the Atchafalaya River and draining the third largest watershed in the world (the Mississippi/Atchfalaya River Basin, or MARB ). Agricultural stormwater runoff from the watershed, rich with fertilizers and animal manure, delivers nutrients to the Rivers and ultimately to the Gulf. These nutrients feed oxygen-consuming biological processes at a faster-than-normal rate, leading to hypoxia and the death of aquatic life.

Urban stormwater runoff also contributes to hypoxia. Combined sewers in many older cities are designed to collect both wastewater and stormwater through a single pipe, carrying the combined flow to a treatment plant. Combined sewer systems are equipped with a relief flow route, so that during surge events pipes aren’t broken and treatment plants aren’t overwhelmed. When that relief route is used it is called a Combined Sewer Overflows (CSOs). With ever-increasing stormwater events, CSOs are more often delivering human waste, a source of not only hypoxia-inducing nutrients but also potential pathogens like coliform bacteria and E. coli, directly into waterways.

Another stormwater-associated issue that is occurring more frequently is flash flooding. Stormwater and floodwaters are not exactly the same. Flooding is specifically the escape of waters from artificial containments, like canals and reservoirs, or from natural waterways like streams, rivers and lakes. There is thus a close connection between stormwaters and floodwaters, since the former can certainly contribute to the latter. But of course, there are floods that are not caused by stormwaters. In either case, both will carry whatever pollutants they have encountered or soils they have stripped into large river systems and ultimately into the Great Lakes and Oceans.

What Stormwater Solution is Right for You?

Communities have saved tens of thousands to hundreds of millions of dollars by implementing a Stormwater Monitoring Solution.

In our experience, there are three types of Stormwater Monitoring: Event Monitoring, Continuous Monitoring, and Decision Support that is an extension of Continuous Monitoring. Read about each type below, including how real-world communities have designed their own purpose-built Stormwater Monitoring Solutions.

Event Monitoring

• Portable, easy to deploy go where the storm is system
• be as simple as a single sensor with internal logging
• May incorporate a ProSample automated sampler
• Add a plug-n-play Storm datalogger with cellular telemetry to HydroSphere, where alerts and notifications can be added
• Highly cost-conscious options are available

Event Monitoring Case Study

Flood Monitoring

• Early flood warning alerts based on both monitored and modeled data
• Bridge and Road submergence monitoring capabilities
• Flood mapping at the parcel or roadway for risk assessment
• Automated “High Water” street sign flashing based on real-time water levels

Flood Monitoring Case Study 

Continuous Monitoring

• Fixed monitoring stations at critical sites of interest, often in a network of sites
• Multiple sensors or samplers are possible, and flexibility to change them at any time
• Programmable dataloggers with cellular telemetry to HydroSphere, with alerts and notifications
• Optional installation of conduits, platforms, and other critical infrastructure
• Data quality control and basic analytical services as needed

Continuous Monitoring Case Study