Roger Clapp has spent years figuring out how to compel the community to reduce the sediment running into the Tuckasegee.

On particularly rainy days, the river nearly runs red, eliciting its fair share of astonishment from those who glance at the river out their window during such episodes. It can take a couple days or more for the pulse of sediment to subside.

“A creek that should run clear and clean hours after a rainfall event is now routinely muddy for days on end during the summer,” said Clapp, director of the Watershed Association for the Tuckasegee River.

Reducing sediment in the creeks and river is a community undertaking, but Clapp needed a way to generate buy-in and collective ownership of the problem.

“I thought why not have a public turbidity meter everyone could see and know how dirty the river was,” Clapp said.

The idea has finally come to fruition with the unveiling of what Clapp calls the “mud meter” on Scotts Creek. Rather than rely on anecdotal observations of the sediment stricken creek, the mud meter assigns a real-time number to how muddy the water is.

“The purpose is to create a little buzz and chatter about the idea of mud and water quality in the creeks that feed the Tuckasegee,” Clapp said.

The mud meter, albeit a fun gizmo making the daily commute for those who drive past it a bit more interesting, it’s intended to give the community pause about the state of the water. The concept is similar to a speed board, the roadside digital sandwich board that flashes how fast you are going, usually prompting you to hit your brakes. The mud meter will hopefully spur a similar reaction when it comes to sediment.

“People need to understand that their creeks should not be muddy for days on end,” Clapp said. “Getting a handle on the amount of muddiness is the first step.”

Volunteers with WATR take water samples at 15 sites in the Tucksegee watershed. Scott’s Creek is consistently the worst, regularly exceeding the sediment levels tolerated by trout. Clapp believed the public would want access to the same data the monitors have.

“We want people to really understand how scientists measure these things. It is not really that difficult. It is really pretty simple,” Clapp said.

Here’s how it works. An underwater sensor shoots a beam of light through the water. When the light hits particles of sediment, it scatters. The more sediment there is, the more the light scatters. The sensor measures the light scatter and assigns it a value on a turbidity scale.

WATR got a grant for $39,000 from the state Division of Water Quality for the mud meter and related monitoring. In addition to recording turbidity, it records the water depth, temperature and mineral concentrations (measured by electric conductivity.) Analyzing the data will offer a series of daily snapshots of how the watershed is performing and what conditions accompany sediment fluctuations.

“The mud meter is a silly name for a serious project,” Clapp said. “We need to protect the river for many reasons instead of having it look good to us. It is the whole ecology of the stream and the stream bed that is affected by overloads of mud to the system.”

The hidden havoc of sediment

Sediment wreaks havoc on the mountain stream ecosystem. The aquatic creatures are held hostage to the sediment raining down on them and have no escape, said Dan Perlmutter, a biology professor at Southwestern Community College. Perlmutter described how sediment fouls up the life of the trout as an example of sediments’ ill effects.

As water passes over the trout’s finely feathered gills, it can both clog and abrade the membranes. When a layer of sediment settles over their eggs on the stream bottom, it can smoother them. It even affects their ability to eat.

“The trout is a vision predator. Too much sediment in the water, it is harder to see,” Perlmutter said.

Sediment can trigger a chain reaction that leads to less oxygen in the water for trout to breathe.

“All that sediment in the water can absorb light and heat and raise the temperature of the water. With higher temperatures, that lowers the ability of water to hold oxygen, which can put stress on trout,” Perlmutter said.

Sediment also blocks lights and inhibits photosynthesis, depleting the abundance of aquatic plants, which in turn reduces oxygen the plants normally give off, Perlmutter said.

Aquatic life that lives on the stream bottom, such as mussels, have a hard time slogging through a layer of sediment. Aquatic insects that live on the stream bottom face the same problem, and as the insects are depleted, it leaves less food for fish.

Reading the mud meter

The mud meter displays the sediment in Scotts Creek in NTU’s, or nephlometric turbidity units. The higher the number, the higher the sediment. The upper limit for a healthy trout population is 10 NTU’s. Scott’s Creek exceeds that standard more than 30 percent of the time. The mud meter updates every 15 minutes.