Places: Shatto Ditch, Indiana

June 24^th, 2014 – Shatto Ditch

You may have seen some of these photos in an earlier post about a specific trip I made back in June. Although you can't see the water in this early July photograph, the grass of the Two Stage Ditch is hard at work.

Above, the Shatto Ditch rushes through

buffer strip between two corn fields.

Bellow, the Two Stage system is more

obvious, with a defined dip into the

artificial flood plain.

A red pickup truck pulled off the farm road onto the grass on the buffer strip of a cornfield. The doors swing open and three stream ecologists deposit themselves into the tall grass and make their way to the back of the truck. It’s old hat now; I’ve made this trip several times and everyone drops into his or her perspective roles. Once we’ve got our hip waders on, our trio pulls out a bucket, pH meter, conductivity meter, SOND software meter, and a few other pieces of equipment.

Our purpose today is to monitor nutrient levels in the Shatto Ditch system of Indiana. The Shatto Ditch is special; it flows directly off the farmer’s fields and into the Tippecanoe River. The Tippecanoe, consequently, finishes its run at the Great Lakes—an important area for the fishing industry in both the United States and Canada. Whenever a farmer enriches his field with manure or fertilizers, the excess nutrients finds its way into the tile drains of the field. It is a system designed to keep the natural waters of the floodplain in the ditches. It works remarkably well and, where once was marshland, now grows agricultural bliss. Unfortunately, all that excess nutrients drains right into the Shatto Ditch and, subsequently, into the Tippecanoe River. Once the nutrients arrive at the Great Lakes, it accumulates at the mouth of the river. Spurred on by the bonanza, algae bloom excessively. Soon, alga grows on alga and the heterotrophs cannot keep up with the astounding rate of dead algae deposition. The amount of decay makes it impossible for fish and other ecologically important species to live. It creates a dead zone.

Fortunately, ecologists at the University of Notre Dame are looking for solutions. One possible solution that we are testing today is the Two Stage Ditch System. To attempt to remove the excess nutrients, like nitrogen and phosphorous, from Shatto Ditch, we have constructed an artificial floodplain about 10 meters wide. It is well planted with grasses and other plants that are naturally competitive for nutrients. The hope is that these Two Stage Ditches will make a difference and limit the amount of nutrients before it reaches the Tippecanoe.

Another possibility is cover crop planting. Some farmers have complied to planting their fields with competitive grasses to help absorb some of the excess nutrients. Right now, it seems like the best solution is a combination of methods.

Here, the Shatto Ditch is measured for discharge, the rate at which water is flowing at a given depth. It is usually measured every 5 or 10 cm and the width of the ditch or stream is also recorded. In this case, a culvert offers a good gradient for this procedure. In front of the tape measure, an ecologist uses a Flo-Mate to make the readings.

Brittany Hanrahan (background) and
Martha Dee (foreground) are the two
Shatto experts at Notre Dame. It has
been a lot of fun working with them.

A conductivity meter is used to monitor

both the temperature and the

conductivity of the tile drain jutting

from the bank.

We took samples at about two-dozen sites, from both tile drains and the ditch itself. By comparing samples taken in the typical Shatto Ditch with those taken at a Two Stage and tile drains from fields implementing the cover crop system with those that do not, the differences will be considered to determine the effectiveness of the innovative plan.

Brittany and I at Shatto.

Turtles are my weakness. They

distract me from my work and I am

helpless to resist.

Sometimes fluctuations in water level, such as flooding after a storm, or other chemical changes caused by fertilizing or watering activities of farmers can give the impression that there are unnatural changes in stream nutrient levels. To watch for this, a variety of other conditions in the stream are also monitored. The pH is usually fairly high as an indicator of high nutrients. Conductivity (the ability of the stream to carry an electrical current) is also fairly high but rises when storms wash debris into the stream. 

The amount and rate of water flowing (discharge) is monitored at tile drains by measuring volume with time. In Shatto Ditch, the width is measured and flow and depth are measured at 5 to 10-centimeter increments with a Flo-Mate, a battery-operated meter, to determine discharge. Temperature is also taken which rises when water flows off sunbaked fields. In addition to all these manually taken samples, SONDs, software-operated water meters are replaced bi-weekly. They collect data 24-7 and can be taken back to the lab measuring any fluctuations in pH, temperature, conductivity, and nearly any other water quality that could be a significant indicator of changes.

I was very impressed by the orange sides of this common garter snake caught at Shatto. There must be a few of them out there because I also saw a red-winged blackbird fly off with one of these snakes. There isn't a lot of wildlife out at Shatto but I've seen leopard frogs, bullfrogs, green frogs, and gray treefrogs among amphibians. Birds include cranes, herons, red-tailed hawks, red-winged blackbirds, song sparrows, mallards, crows, and other songbirds.

All these measurements and samples will be analyzed back in the lab for significant correlations. When the day is done, we strip off our waders, sweaty and wet from leaks in the boots, and climb into the truck. Once everyone is in, we drive for the nearest Steak N’ Shake. It’s a Tank Lab tradition: ice cream for the way home.