Spicer Group Surveyors Map Rivers & Infrastructure to Assist With Solving Decades-Old Flooding Issues

MIDLAND, MICHIGAN - The Tittabawassee River Watershed is the fifth largest watershed in Michigan, with an area of 2,471 square miles that spans across portions of Midland, Isabella, Saginaw, Gladwin, Gratiot, and Clare Counties. The watershed’s rivers and streams flow into the Tittabawassee River, which is more than 90 miles long and has 600 miles of contributing tributaries.

The City of Midland is surrounded by four rivers in that watershed: the Tobacco River, the Tittabawassee River, the Pine River, and the Chippewa River. These waters, and those of their tributaries, meet at the confluence of the Tittabawassee and Chippewa river in the heart of downtown Midland. That confluence is home not only to the popular recreation destination of The Tridge, but also to many local businesses. 

These businesses and their owners—along with hundreds more— have had flooding issues for decades. According to the National Weather Service, the Tittabawassee River has reached the flood stage of 24 feet in Midland over 40 times since the 1930’s, with the most recent crest being in 2020. 

These issues prompted the Midland Business Alliance (MBA) to form a task force in 2021 to examine infrastructure issues within the Tittabawassee River Watershed that affect the quality of life and economic viability of Midland and the surrounding Mid-Michigan areas. That task force - the MBA Advisory Committee on Infrastructure - began investigating ways to work with local, state, and federal partners to address the longstanding flooding issues within the region.

To understand the flooding issues of the region, a technical picture needed to be drawn of the watershed as a whole. Enter the U.S. Army Corps of Engineers (USACE). To understand the flooding issues of the region, a technical picture needed to be drawn of the watershed as a whole. Enter the U.S. Army Corps of Engineers (USACE). 

Through the USACE’s Planning Assistance to States (PAS) program, entities like Midland County and the MBA can get assistance from the USACE with developing a plan for managing water resources, like the Tittabawasee River Watershed, to better understand what infrastructure needs to be in place to prevent flooding-related issues. 

Before a plan could be developed, a technical picture of the watershed was necessary. This hydraulic and hydrologic data gives the experts and engineers in the USACE the ability to see what is taking place within the watershed in that moment in time and the information on the infrastructure that assisted or hindered the natural flow of the rivers. With that data, they can then study the infrastructure in place within the watershed under different conditions, determine where flooding may occur under many different rain/ground saturation conditions, and then determine where—and how much—potential floodwater infrastructure is needed to reduce the impact of the flooding. 

“The Midland Hydraulics and Hydrology Study is the largest area we have modeled under PAS,” Gregory Mausolf, the Public Affairs Chief with the USACE Detroit District said. “Most PAS studies are about the size of just one or two tributary rivers— not all of them plus the Tittabawassee River!”

Spicer Group surveyors were hired by the MBA’s Advisory Committee, Midland County, and the USACE to collect the necessary data and conduct hydrological and hydraulic surveys along the rivers and their tributaries within the watershed. This included the Tittabawassee River, Sturgeon Creek, Snake Creek, Bullock Creek, Salt River, Chippewa River, and Pine River.

During the surveying process, Spicer Group survey crews collected precise surveying measurements and data points of bridges, culverts, river crossings, river depths, river cross sections, and more. Surveyors worked through the winter to gather this information on 57 bridges, five industrial crossings, and one dam. 

Some of these bridges, including the Tridge in Midland, were too wide and in water too deep for physical, traditional surveying to complete the necessary data collection. In these cases, the Spicer team used photogrammetry from the Unmanned Aerial Vehicle (UAV) equipment to measure the distances needed for the study. 

Along with valuable measurements, Spicer Group’s surveying crews collected photos at all cross sections, bridges, culverts, and water crossings to help the engineers at the USACE gain valuable insight into how the waterways looked throughout the entire survey area. Spicer surveyors also gathered important notes on each bridge and culvert so that accurate hydraulic modeling could be performed at each crossing.  

In all, the Spicer team surveyed over 66 miles of waterway to fully capture the 3D modeling needed of the watershed through the Midland, Michigan, area. In addition to collecting the necessary data, Spicer Group’s team also merged that data with existing LiDAR, bathymetric, and traditional survey information to make one cohesive, synergetic package to deliver to the USACE to use in the study. 

“The (USACE) needed all of this information and they needed it quick,” Spicer Group Project Manager Jeremy Dancer, P.S., said. “This project incorporated many different types of surveying and data collection on many different types of infrastructure. When you have just one bridge within a project, it is only one set of notes and plans. But when you have multiple bridges, culverts, and pedestrian areas, it is different.”

“We needed to have each scenario laid out in our project plan before our field teams were on the ground, so they knew what to do no matter which obstacle they encountered on a site,” Dancer added.

Surveyors had less than three months to complete all the data collection necessary because of weather and deadlines set in the planning stages of the study. To access some areas of the river, boats and waders were necessary. 

All of the data was also uploaded online into a read-only view for the MBA, Midland County, and USACE to view the data as it was collected and merged in real time. Spicer surveyors assisted in filling in any gaps and points deemed necessary by the USACE once the data was being analyzed. 

“This was a very large study area with a massive amount of survey data to be collected. Spicer was able to collect the needed data, provide the survey points, bridge sketches, and photos in a very organized way, which greatly helped the usability of the data,” Mausolf said.

Once the entire study is finished, the USACE will have used that surveying data to make recommendations on infrastructure changes or improvements to help prevent flooding issues in the future.