The Upper Manistee Gets Decades of Trees Added

by Kristin Thomas, Michigan TU Aquatic Ecologist

This past September, the Upper Manistee River finally got a lot of love. Michigan TU worked with the Upper Manistee River Collaborative, Kanouse Outdoor Restoration, CHI Aviation, and Trout Unlimited to make significant improvements. One hundred fifty whole trees were added to a section of the river that had become wide and shallow and lacked wood cover. The purpose was to add the large wood material in ways that would allow the river to recover its shape and help fisheries, a process that, left to its own devices, might not have occurred in the rest of our lifetimes. Many reading this might have seen the photos and videos of the project, but here’s more to the story.

The place to start is the formation of the Upper Manistee River Collaborative. This group has been discussed in several past articles so the back story will be brief. The Collaborative was born from the desire to improve the fishery in the Upper Manistee in a meaningful way. Local river guide Chuck Hawkins brought an individual donor, Dick Audi, to Michigan TU. Dick was interested in donating the seed money necessary to identify limiting factors and priority projects. His generosity was the catalyst for this project.

Existing information about the system must be compiled and assessed to identify limiting factors. The only way to figure out what might limit a fishery is to learn what is currently there. After looking at available data and collecting more, the Collaborative decided that the area most in need was between Yellow Trees Landing and CCC Bridge, emphasizing the upper three miles from Yellow Trees Landing to Roger’s Landing.

This river stretch has many wide, sandy, shallow areas with limited habitat diversity. The river is not functioning well in these places, which are overly wide, leading to low water velocity and allowing sand to drop out and deposit. The data and the stakeholders pointed to this problem as a high priority. It has been an increasing issue for some time, but it is a challenging area for a project. There is little access, and the river is relatively large, so heavy equipment can’t get to most places, and handwork from the water isn’t enough to move the needle in many cases. So we knew the logistics of taking on this project would be challenging, but the whole point of the Upper Manistee Collaborative is to take on the hard work. Whether simple or complicated, the work that will make a difference focuses on what the resource needs.

The Upper Manistee River is a very low-gradient system. That is to say, the slope or pitch of the river is very low, almost flat in many cases. A river’s primary jobs are to move water and sediment. Every river has a natural and functional sediment load. The slower the water flows, the smaller the size of particle that can be carried. Water moving very fast can move bigger particles. A languid river can only carry sand and fine organic material; eventually, even that begins to drop out as water slows.

In low-gradient sandy Michigan rivers, wood is the natural mechanism to support sediment transport and deposition. Because Michigan doesn’t have many steep sections of stream, wood changes the speed and direction of flow to create diverse habitats, producing places where sediment is scoured, and sediment can settle. Without ample wood, flow is monotonous, and sediment drops out, resulting in very slow, wide, sandy, shallow areas. Wood helps restore that diversity and create a functional river. When rivers have a low slope and are wide and shallow, water velocities are low, and more sediment accumulates. Adding wood is like putting a thumb at the end of a garden hose of flowing water; it speeds up the velocity. For a deeper dive into this topic, see the Michigan Trout article, “The Critical Role of Wood in Michigan Rivers: Taking Action on the Manistee,” published in the Fall/Winter 2021 issue.

But why is there a lack of wood in the Upper Manistee? The answer is two-fold; humans and an incredibly stable flow regime. Humans have disrupted the natural wood recruitment cycle. Clear cutting of Northern Michigan forests greatly changed the age structure. Instead of having a mixture of old and young trees, all the trees were young. This meant a disruption in the cycle of trees getting old and falling into the river naturally as the forest aged. This disruption lasted for years as trees grew, creating a significant gap in wood recruitment. In addition, humans have taken wood out of the river (fortunately, less so recently!), resulting in an overall decrease.

The second factor in the Upper Manistee is the stable flow regime. The Manistee is one of the world’s most stable rivers, meaning it rarely floods, and even when it does, the water elevation does not change very much. This means wood is not carried into the river from the forest during flood events. The water does not get high enough to recruit wood from the riparian area. Additionally, the stable flow regime and associated lack of flooding mean the river can’t clear sand on its own. There isn’t enough power.

The combination of these factors means the Upper Manistee has artificially low wood levels in many locations. This observation was further supported through pre-project data collection. The large woody debris index (a quantitative measure of wood in rivers) in identified work areas was markedly lower than in “reference” areas with ample wood. The values in work areas were also lower than the statewide level for a functioning river. This provided clear support for adding large wood habitat.

A project can’t grow and mature without funding. The Collaborative agreed to have Michigan TU lead the effort to acquire the financing for adding woody habitat between Yellow Trees and CCC Bridge. Michigan TU would also act as the project manager for funded work. Armed with the evaluation of habitat, fish, and temperature data, a convincing picture was painted to illustrate the need for habitat improvement.

Funding was acquired from the Michigan DNR Fisheries Habitat Grant Program, the National Fish and Wildlife Foundation Sustain Our Great Lakes Program, and several generous individuals. The method of installation was not specified in the grant applications. The Collaborative decided to work through ideal designs and figure out how to build them. Again, this project was about making strides toward a better fishery by creating better habitat and a more functional river. Cost and logistics were secondary concerns, still essential, but functional design was foremost.

As designs began to unfold, it became clear that the most challenging part of the project would be river access. There is minimal vehicle access between Yellow Trees Landing and CCC Bridge, especially between Yellow Trees Landing and Roger’s Landing, which was the primary area of focus. The use of heavy equipment to place wood from shore was not ideal. The geographic scope of work would have been significantly decreased because of the lack of access. New temporary access sites would need to be created. No one was excited about this option because of the disruption to the riparian area, and temporary access points have a way of becoming permanent. In addition, we wanted to ensure the protection of many threatened and endangered species that call wetlands in this area home. So, if not excavators, then what? This question is where a collaborative group shines; diverse thoughts and ideas come up with creative solutions.

After much discussion and careful thought, the group decided the best techniques were hinge-cutting of riparian trees and helicopter placement of whole trees (trees knocked down with an excavator, roots and all). These two techniques are at opposite ends of the cost spectrum. Hinge cuts are inexpensive and logistically easy. Work can be done by hand from the river. Helicopters are expensive and not at all easy logistically. Therefore, part of this project evaluated these two techniques regarding the benefit to the river and return on investment.

Phase one would be hinge-cutting 135 trees between Yellow Trees Landing and CCC Bridge. Phase two would be placing 150 whole trees in the river between Yellow Trees

Helicopter delivering a whole tree. Landing and Roger’s Landing via helicopter. Phase one was completed in 2021; 135 riparian trees were partially cut and pulled into the river to increase fish habitat and create a diversity of flow. Phase two was completed in 2022; 150 whole trees were placed in the river via helicopter also to create fish habitat and increase habitat diversity. Many of the entire trees were placed in locations where no riparian trees were available for hinge-cutting. The helicopter work took one long day of flying, and the planning and site preparation for the helicopter work took months. Michigan TU did much of the applying for the required EGLE and DNR Natural Rivers permits. There needed to be a location for trees to be staged and picked up. Ideally, that location would be the same as the tree harvest location. We had to have a site for the helicopter to land and refuel throughout the day. A State Land Use permit was required for these sites and tree harvest. The flight path to each work site also needed to be clear of cabins and people. Jet boats were necessary to traverse the river and guide the placement of the trees, with ground crews to hook trees to the helicopter and ensure the roads and river stayed closed in the work area. A water-based team was needed to communicate with the pilot about placement, and another water crew to pull cables and bring them back to the staging area. This was a lot of logistical preparation; a lot. But great preparation means great success on the work day. Although the weather was cold and rainy, the work went off without a hitch (so many thanks to Kanouse Outdoor Restoration for their incredible prep work), and the sun even came out for the last couple of trees. The helicopter crew was amazing, and so was the actual helicopter named Rhonda. The pilots love precision ...continued on page 23