Quantifying Stream Restoration Benefits

IRIS researcher Dr. Rod Lammers builds on stream restoration crediting programs

Writer: Cammie Caldwell

Contact: Dr. Roderick Lammers; rod.lammers@uga.edu

The streams and rivers of the United States are a form of infrastructure that provide communities with clean water to drink, irrigation for agriculture, habitat for plants and animals, and the water necessary for industry. However, increasing pollution, nutrient overloads, erosion, and deforestation cause water quality issues that threaten the delicate systems that work within them to benefit our society.

Dr. Roderick Lammers, Research Scientist at the University of Georgia, is addressing these challenges by developing a way for industry and other organizations to even the debt with our freshwater resources through stream restoration crediting programs.

Specifically, Lammers has worked alongside Wright Water Engineers, a Denver, Colorado-based engineering firm, and other UGA researchers to create methods for quantifying benefits that stream restoration activities may provide.

While these methods are applicable to stream restoration projects everywhere, they are receiving the most attention in parts of the country with significant water quality challenges.

With an estimated 51 billion gallons of water flowing into it on a daily basis, and runoff from five states, the Chesapeake Bay receives large amounts of pollutants, and it has served as a starting point for researchers developing crediting programs.

The states that contribute to run off in the Chesapeake have been aiming to improve water quality by encouraging stream restoration and other projects, making it a source of innovation in the field. In fact, Lammers has adapted many of the methods originally developed by the Chesapeake Stormwater Network.

His project is intended specifically to help state and regional agencies set up their own crediting programs.

“The document we’re putting together is targeted mainly to state or regional agencies who are responsible for setting up crediting programs having to do with stream restoration,” Lammers said.

Stream restoration projects are often taken on with a lack of understanding and measurements about the possible benefits they could provide. This is due to the fact that monitoring of stream restoration projects can take extensive time and money to perform.

“We want to develop a database around performance of stream restoration projects. Currently, few of these restoration projects are monitored and it is often unclear how well they work. We want to be able to quantify how much nutrient reduction one of these stream restoration activities would cause,” Lammers said.

To combat this gap in knowledge, Lammers is setting out to create quantification methods that focus on four major types of stream restoration strategy, each with its own formula.

The first, bed and bank stabilization, helps to prevent erosion and the release of phosphorus into the stream. Lammers is able to estimate the benefits of this type of project by measuring levels of erosion before and after the project, then calculating the amount of phosphorous reduced by stopping said erosion.

Next, the creation of riparian buffers traps sediment and pollutants within natural vegetation along streams before they can reach the water. These are assessed based on the size of the buffers and estimates of how many nutrients they can remove from an area.

“Another strategy is stream enhancement, which involves putting structures in the streams like rocks, logs, or anything to stabilize the channel,” Lammers explained. “These projects are assessed by how well they improve the filtering capacity of the stream and their contribution to water quality.”

The last is floodplain reconnection, which works to make the stream channel and floodplain act as a unit to reduce erosion and improve water quality. To measure the benefits of this strategy, Lammers calculates how much water moves through the connected floodplain and how much pollution removal has been removed.

The methods and databases that Lammers is working on will benefit small, regional projects but also work toward larger goals, such as developing a platform for water quality trading programs, which would allow industrial partners to conduct restoration projects to compensate for pollution.

“We want to create a marketplace that will encourage the most effective ways of improving water quality. For example, if a wastewater treatment plant is unable meet EPA limits on the amount of nutrients they discharge, it may be cheaper for them to pay for stream restoration projects that could result in improved water quality in a more efficient way, rather than installing expensive upgrades at their facility,” Lammers explained.

Through Lammers’ and his colleagues’ research, we will be one step closer to having the tools we need to effectively restore the waterways that our communities so depend on.

This work was made possible thanks to the Water Research Foundation.