Sustain Our Nation's Forests and Grasslands

Aquatic Organism Passage Workshop promotes shared stewardship

INDIANA — At the end of October, Hoosier National Forest hosted a Designing for Aquatic Organism Passage at Road–Stream Crossing Workshop. The 4 1/2-day workshop drew 54 attendees from state and federal agencies in Connecticut and Massachusetts, as well as from the Ouachita, Wayne and Gila national forests. The course provided engineers, biologists, hydrologists and other disciplines the necessary skills to design road–stream crossing structures that will accommodate aquatic organism passage, provide more natural channel function and maximize the long-term stability of the structure. The primary design approach for aquatic organism passages is stream simulations.

Individuals were grouped into teams of 7–8 people based on experience with road–stream crossing projects and different career specialties. The class was presented with data throughout the week, culminating in group presentations on how they would replace an undersized culvert at a known location. Students were first introduced to the topic of stream simulation and the ecological importance of correctly designed road-stream crossings. The instructors then led the class through concepts such as longitudinal profile, channel planform characteristics, reference reach, channel cross sections, bed material size and arrangement, structure selection and design considerations, final design, and contract preparation and construction.

In the middle of the week, the students were taken into the field to see several examples of poorly designed road–stream crossings. The students got hands-on experience measuring such parameters as bank full width, flood prone width, cross sectional width at max pool depth and cross sectional width at riffle head crest. Instructors showed proper procedures for performing pebble counts, correctly interpreting bank full and flood prone width as well as discussing the proper way to design and replace the current structure.

The workshop took place at Four Winds Lakeside Inn on the shores of Lake Monroe in Bloomington, Indiana.

Photo: Group of people in hiking gear listen to instructors atop a culvert in a forest.
Instructors Dan Cenderelli (orange Vest) and Bob Gubernick (brown vest) explain to the class what the tasks would be entailed in the Squirrel Town AOP project on Starnes Branch. Photo courtesy Debra King, Indiana Department of Natural Resources.
Photo: People hike through forest and along stream. The ground is covered with fallen leaves.
Participants in the workshop took field trips. One such stop was at the undersized box culvert at the Combs Branch crossing of Tower Ridge Road, Hoosier National Forest. Photo courtesy Debra King, Indiana Department of Natural Resources.