Exploring innovative methods for stormwater infiltration and sediment control

An effective stormwater infiltration system needs complementing sediment control methods. Stabilization efforts improve the soil's structure and permeability, helping stormwater sink into the surface. Additionally, stabilized soils withstand compaction, mitigating surface runoff and enabling better absorption.

Erosion control methods stop soil displacement and sediment buildup, helping the stormwater infiltration systems maintain optimal performance. They also preserve water quality and make sediment-related blockages less likely.

Stormwater management professionals must familiarize themselves with forward-thinking infiltration and sediment control methods, particularly as many areas experience more frequent or increasingly severe weather. Success makes places more resilient to heavy rainfall, while inadequate methods result in them being prone to flooding and experiencing water quality issues. Which options should those responsible consider when preparing locations to handle current and future needs?

Permeable pavements within the stormwater control system 

Permeable pavements are increasingly popular options for stormwater control systems. These surfaces allow water to drain through them rather than collecting above the ground. In one case, researchers indicated the pavement could capture 70% of the rainfall, so only 30% became runoff.

Careful planning regarding how and where to use permeable pavement can also benefit nearby tenants while saving money. One example involving a medical practice saved the developer more than $200,000 while virtually eliminating runoff, which benefited the people using that building and surrounding renters.

Some customers also seek to use permeable pavements to keep dedicated areas accessible to everyone after rainfall. Such was the case when local council authorities in Australia experienced ongoing issues with a gravel area surrounded by mature pine trees.

The eventual solution protected the trees and controlled stormwater, thanks to the use of a heavy-duty geofabric layer alongside other sediment control methods. The team also used a resin-bound permeable pavement over a porous concrete base as part of this stormwater infiltration system.

However, appropriate use of permeable pavement requires consideration of factors such as the average amount of annual rainfall and how quickly the chosen surfaces will absorb water.

Fee structures to fund stormwater and sediment control methods

People invariably notice if their areas lack adequate stormwater and sediment control methods. However, they do not always think about how those infrastructure improvements are funded. Some decision-makers have addressed that matter with various funding structures, such as stormwater fees and credits. The charges are typically taxes imposed depending on a property’s total impervious surface area. Conversely, a property owner can benefit from credits earned when they install a stormwater infiltration system or similar methods to reduce the likelihood of flooding.

In 2024, officials from a city in New Jersey took that approach by introducing a stormwater utility and requiring all property owners to contribute to the associated infrastructure costs. The plans involved subjecting most homeowners to a quarterly $19.25 charge. Those involved in implementing this program anticipate it will generate an annual revenue of $1.5 million.

Similarly, Washington, D.C., has a program where people can generate and sell stormwater retention credits after installing qualifying green infrastructure. Such options give decision-makers greater control over their revenue-generation methods. They allow them to see how certain choices simultaneously improve stormwater management methods and benefit all of an area’s constituents.

California residents must also account for stormwater fees before planning specific and relevant construction projects. Those involved secure permits and pay the required amounts before proceeding. Additionally, the state requires qualified developers to plan how they will mitigate pollution caused by stormwater runoff.

Green infrastructure projects to control stormwater 

Green infrastructure projects encompass options such as rain gardens and green roofs. Sometimes, the purpose spans beyond stormwater management, recharging groundwater or allowing more water reuse. Areas needing more green infrastructure may have streams with water levels that rise and fall quickly, which can make flooding more intense when it occurs. Additionally, increased sedimentation linked to floodwater can make streams shallower and at a higher risk of causing problems.

Urban sprawl can also increase stormwater problems, especially if an area has unsuitable characteristics for flood management. Consider how Houston, Texas, had an increase of 1.3 million residents in 23 years. Although that city has become an increasingly popular place to live, much of its metropolitan area consists of converted wetlands, which can worsen flooding.

However, besides assisting with stormwater infiltration management and sediment control, green infrastructure can be aesthetically pleasing, adding many attractive features to frequently used community amenities. In one example, a New York City playground featured green infrastructure that naturally blended into the landscape and made the area look more appealing to visitors.

Students and staff members collaborated to design the playground, which features volleyball and basketball courts, picnic tables and an outdoor classroom among its perks. Additionally, estimates suggest the chosen green infrastructure will be impressively effective at stormwater management. Those involved expect it to soak up 720,000 gallons of water every year.

Some green infrastructure management efforts require studying the area’s natural resources and their confirmed impacts. Consider the example of a Simon Fraser University team that realized measuring the speed of sediment flow in rivers would help planners prepare for severe weather. They confirmed that grain shape affects transport rates and could impact sediment control methods.

Hemp fiber as an addition to sediment control methods

Hemp fiber is an emerging possibility that some infrastructure professionals have considered to improve their sediment control. Many companies sell it as blankets used to control erosion in areas ranging from construction sites to steep embankments bordering roadways. When businesses sell hemp fiber on rolls, it is easy to transport and apply.

Additionally, some products can hold up to 1,050% of their weight in water, making them ideal for flood management. Infrastructure professionals can also purchase 100% biodegradable hemp, prioritizing products that align with sustainability goals.

Besides assisting with weed control, hemp fiber blankets encourage the rapid establishment of vegetation characterized by strong rooting. This stabilizes the soil, making complementing stormwater management methods more effective.

Hemp naturally decomposes, but most commercial fiber blankets last at least two years after application. Moreover, this material is safe for wildlife, and many companies specifically make their products without grid patterns that could cause animals to get stuck when walking across it.

A potential downside is that hemp is not yet as widely used as some alternatives. That could make it more challenging to convince decision-makers that now is an excellent time to use it.

Selecting a stormwater infiltration system or sediment control method

All sediment control methods and techniques to reduce stormwater effects have associated pros and cons. Those evaluating them should consider factors such as their budget, timelines and suitability based on current and future needs before determining that a particular option is the best choice. Getting feedback from the community and studying the potential impact on a local area is essential to avoid unintended consequences.