Every volunteer who monitors water quality in a local stream does it for a reason. It could be a funny smell coming off the water. Maybe someone was worried about their dog splashing through a local creek. Or maybe they wanted to be sure what came out of the tap was safe to drink.

For a group of anglers in northern New Jersey, the reason was trout.

Low Flows Land Fish in Hot Water

The Pequannock River starts as a cold, clear stream in the New Jersey highlands and runs southeast for 20 miles. Trout production streams are more of a rarity in northern New Jersey than I would care to point out, and this one was subject to the same development pressures facing many streams across the country.

In the late 1990s, a group of anglers noticed their favorite trout fishing holes along the Pequannock River were suffering from fish kills and they wanted to know why. (Actually, they wanted to fish. But to do that, they needed to find out what was killing the trout.) They took their questions to local, county, and state agencies responsible for enforcing the Clean Water Act but got no answers. Eventually, the anglers figured out the answer themselves: the fish were (literally) in hot water.

Trout depend on cold, clean water, and temperatures in the Pequannock River had become too warm for the fish to survive. The cause of the problem also turned out to be the solution: a large water reservoir and a dam.

The dam built to create the reservoir was holding back so much water that temperatures downstream were too high — and water levels too low — for native trout to survive. It also turned out that New Jersey had no regulations on the books related to water temperatures for fish and wildlife and no baseline data showing that water temperatures were a problem.

The anglers formed the Pequannock River Coalition to raise awareness of the issue, rally volunteers, and gather the baseline data the state needed to address the problem.

Volunteers placed data-logging temperature sensors (fancy digital thermometers) along the river and in its tributaries, including their favorite fishing holes and other areas of concern, to collect temperature readings every 15-30 minutes, every day. They quickly found that the streams feeding into the Pequannock River often exceeded 83 degrees Fahrenheit — the temperature threshold for healthy trout.

The coalition collected data for several years and submitted it to the New Jersey Department of Environmental Protection to demonstrate the problem. The state agency was then able to work with the dam operator to figure out the right amount of water, the right water temperature, and the right amount of oxygen needed in the water released from the dam to support native trout.

I am sharing this story with you for a few reasons. First, our streams and our communities need us to take a stand for clean water. Second, because this group of water defenders didn’t need to monitor every type of pollutant out there. They decided what worked for them and kept a narrow focus. Finally, they used their data as a tool and they stayed the course with their plan of action.

What’s Your Reason?

The Izaak Walton League is working with volunteers across America to give communities the tools they need to identify and solve water quality problems.

Whether you have 10 minutes today or 10 days throughout the year, we have a monitoring option for you. Our signature program — Save Our Streams — provides many options to track trends in stream health. Earlier this year we launched the Winter Salt Watch because we were concerned about the effects of excess road salt on stream health. One simple test using chloride strips gives volunteers the data they need. One of our Stream Selfie volunteers posted a photo of a beautiful stream — and a note that the stream “looks like poop after it rains.” Tests for bacteria and total dissolved solids can help this volunteer determine whether fecal coliform levels are spiking after every rain event.

If you’re ready to get started with stream monitoring, check our training schedule at iwla.org/workshops and the resources in our Clean Water Challenge Toolkit.