Water management has always been a significant concern in our home state of Utah. Early settlers built a series of canals, waterways, irrigation ditches, and reservoirs to help increase water access and make the ground more fertile. According to historical research from Utah Humanities, each county appointed a watermaster during the early days of settlement. This person’s role was to travel to farms, checking irrigation canals and ditches. Each farm had its headgate and measuring weir connected to the canal system. The water master carried a measuring stick to measure the water depth and flow. They would adjust to allow farmers more or less water while maintaining enough for the whole community. It was a difficult position, and farmers often attempted to take more than their fair share of water by adjusting their farm’s headgate. This practice was known as ‘midnight irrigating.’
Water masters are no longer needed today, as our irrigation and water management systems have become much more sophisticated. But it’s interesting to see how essential water management practices were, even from the early days of settlement in Utah. Water is a precious resource, and in today’s world, we have sophisticated tools and systems to manage water resources. Stormwater management systems are one of the most critical tools in water management. New sustainable stormwater management practices are becoming increasingly crucial to responsible water management, ecological health, and pollution prevention. As a civil engineering firm that designs stormwater systems, we wanted to share more about these practices and how they are changing traditional stormwater management systems.
The need for sustainable stormwater management
Stormwater management systems are crucial for preventing flooding, water run-off and pollution. In a natural ecosystem untouched by development, nature typically absorbs stormwater run-off. But in urban environments, we must design systems to funnel stormwater away. Traditional stormwater management systems like storm drains, canals, and pipes are called gray infrastructure. The goal of these systems is to channel run-off away from urban areas.
The problem with gray infrastructure systems is that they don’t fitler the water as it’s collected, and the water picks up whatever it passes through, including toxic chemicals from vehicles, pesticides, fertilizers, manufacturing chemicals, industrial waste, and more, which pollutes the water. According to the EPA, storm run-off water is becoming one of the fastest-growing sources of pollution and a significant cause of water quality problems, which poses significant health risks.
Green stormwater management systems may be the answer
As we learn more about the dangers of stormwater pollution, new management practices that replicate nature are being explored. These practices, known as green stormwater systems, are designed to replicate natural processes. For example, in an undeveloped forest, stormwater is absorbed by the porous environment. Trees and plants naturally soak up stormwater, filtering it and reducing run-off. Two water management needs must be considered to replicate this process in urban environments,
- Water retention: Preventing run-off by capturing it where it falls so it can then be filtered into the earth and returned to the atmosphere through evapotranspiration or reused for landscape needs.
- Water quality: Decreasing the amount of stormwater that reaches waterways and filtering out contaminants from any water that does make it to waterways.
We’re learning a lot about different tools and green stormwater management systems that can help meet these needs. Some systems that are being explored include:
- Green roofs: Installing vegetation on rooftops, such as grasses, wildflowers, vegetable gardens and more, is an excellent stormwater management tool. These roofs have several benefits, including providing extra insulation, absorbing carbon pollution, and retaining rainfall. Between 40-80% of the total volume of rain that falls on a green roof is retained and then slowly released over time, curbing flooding, erosion, and pollution.
- Blue roofs: Like green roofs, the goal of blue roofs is to collect rainfall to reduce run-off into gray stormwater systems. Instead of greenery, detention ponds, basins or trays are installed on rooftops to collect rainfall. This water can then be reused for landscaping purposes. Rainwater harvesting, like the kind used in blue roofs, has the potential to meet 21-90% of a city’s non-potable water needs.
- Rain gardens: Installing gardens and greenery alongside sidewalks and streets is more than pretty landscaping. These greenery sites are essential for capturing, absorbing, and filtering water run-off. Unlike traditional lawns, rain gardens that include shrubs, perennials, and native plants are 30% more absorbent. In Seattle, they did a study called the 12,000 Rain Garden Campaign, and researchers estimated that a single rain garden can fitler as much as 30,000 gallons of stormwater a year, and 12,000 rain gardens can absorb up to 160 million gallons. A larger version of rain gardens, known as bioswales, are also very effective. A bioswale is a long, deep channel of native plants, grasses, flowers, and soil that runs next to parking lots, roads, and highways to prevent run-off. The City of Lincoln estimates that bioswales can capture and filter 90% of solids, 80% of trace metals, oils, and grease, and 65% of phosphorus from water run-off.
Let us help with your stormwater management
We incorporate gray and green stormwater management practices in our civil engineering practice. The integration of these systems ensures effective stormwater management while maintaining ecological balance. We also apply green infrastructure techniques to enhance the overall design of our landscape architecture projects to be more sustainable.
As our understanding of water management improves, green stormwater practices are becoming more common. As we learn more about how effective nature is at water management, green stormwater practices like these will become more common in developments, and we’re excited to see the changes that will come into stormwater management processes and technology!
