Stormwater management made easier with turfgrasses

Climate-resilient cities should turn to turfgrasses for stormwater management

Cities are facing increasing challenges from climate change, including the need for resilient and efficient solutions for stormwater management. Of all the options available, grasses are the simplest, most natural component in solutions to manage stormwater and prevent flooding. Additionally, grasses offer a powerful, adaptable, and low-maintenance solution. They should be at the heart of a more efficient, low-input infrastructure for flood prevention in your city.

Grass – the green game-changer for urban stormwater run-off

From controlling erosion to maintaining water infiltration, grasses are resilient to floods and drought. Grass species are easy to establish, low-cost to maintain, and are adaptable to a wide range of environmental conditions. They are perfect for urban stormwater projects and for municipal climate-adaptation strategies.

Prevent clogging of soakaways

A common problem in stormwater management solutions is surface clogging, in which soil and pollutants accumulate to form a sediment that reduces water infiltration. Grasses such as creeping bentgrass and smooth-stalked meadow grass are particularly effective in countering this problem. These grasses form rhizomes and stolons to spread across sediment deposits, and thereby help maintain the soil structure and the infiltration capacity.

Combat erosion with grass

Erosion is a recurring issue in stormwater management solutions with plants, especially in solutions with some extent of bare soil. Grasses are a natural defence against erosion because they establish rapidly, and go on to form dense root systems. Fast-growing species such as Westerwold ryegrass act as nurse grasses, quickly stabilising the soil. Other species, such as tall fescue, develop deeper root systems that anchor soil layers and prevent erosion, while creeping bentgrass forms rhizomes that cover the ground quickly. These grass species are ideal for preventing soil loss; they’re a critical component of stormwater management solutions that experience frequent water surges.

Grass for tolerance to weather extremes

Stormwater-management systems must cope with extreme weather conditions – heavy rains and prolonged droughts. Grasses excel in changeable environments like this because of their broad tolerance to hydro extremes. For example, tall fescue and smooth-stalked meadow grass can endure periods of immersion in standing water, while grasses such as red fescue and hard fescue have drought-resistant traits that enable them to thrive during dry spells. Mixtures that balance these extremes ensure that vegetation remains healthy all year round.

Fescues thrive in poor growing conditions

Many stormwater-management facilities, such as permeable pavements, provide unsuitable conditions for plant growth as they typically use nutrient-poor, gravel-based substrates. But some grass species can handle these tough growing conditions. Hard fescue, sheep’s fescue, and red fescues perform exceptionally well in nutrient-poor, dry settings. They will grow in the most challenging conditions.

Grass supports the filtering of pollutants

To maximise the filtering of pollutants in soakaway stormwater management solutions (constructed using filter soil), water should infiltrate uniformly across the surface. If preferential flow paths develop, the filtration process becomes compromised. The easiest way to counteract this tendency is to establish turfgrasses with fibrous root systems. The fibrous root systems of creeping bentgrass, tall fescue, and slender creeping red fescue even out the flow of soakaway water; they support the filtration process.

Salt-tolerant species to maintain roadside greenery

On roads where winter salting is common, salt-laden run-off can damage vegetation in roadside stormwater management solutions. While no plant tolerates high concentrations of salt, some grass species have significantly greater tolerance. Tall fescue, creeping bentgrass, and slender creeping red fescue are particularly salt-tolerant; they are ideal for roadside stormwater installations. 

Grass mixtures: the most versatile stormwater solution

Turfgrass is the easy and most versatile plant solution to many of the problems connected with stormwater management.

By choosing the right combination of species and varieties, you can sow a seed mixture that’s optimised for your own local conditions.

To learn more about how turfgrasses can support a natural, low-maintenance stormwater-management system, speak to your local DLF representative.