Shallow river survey from an inflatable raft with the CEE-LINE™ and Trimble TSC7

About Midwest

Midwest is a 75-year-old engineering company providing survey services throughout Canada. Often working in remote locations, Midwest has performed river crossing surveys across Western Canada since the early 2000s, adapting its equipment and methods to everything from small wading creeks to large navigable waterways.

For smaller crossings, Midwest’s field crews typically use RTK GNSS. Larger rivers need a 15-foot inflatable boat powered by a 40 hp jet motor, with a mounted single beam echo sounder.

The challenge

Some rivers present unique challenges, and the upper reaches of the Red Deer River are a prime example: a highly braided system with a narrow, deep main channel and no boat launches. Even if a motorised boat could be launched, shallow gravel bars would block access further on.

Midwest’s client has monitored bank erosion and riverbed scour at the site for over a decade. In that time the main channel has shifted about 1,000 m, from the west bank of the valley to the east bank, and in the past three years the east bank has receded by roughly 5 m, threatening critical infrastructure.

A lightweight, portable echo sounder was needed that could be mounted on a small inflatable raft in this extremely shallow river, with survey depths often just a few inches below the transducer.

The solution

Midwest added the CEE-LINE™ single beam echo sounder kit to its existing Trimble R12i GNSS and TSC7 data collector setup, and installed it on an inflatable raft that was paddled along the river.

The CEE-LINE™ and TSC7 make a simple survey setup. The CEE-LINE™ connects with a single USB cable for a true plug-and-play result: the CEE-LINE CONNECT™ app controls the echo sounder while Trimble Access collects the survey points.

The survey

The crew launched upstream of the target area and paddled downstream, making multiple passes to capture accurate riverbed positions and elevations. By combining the echo sounder data with RTK measurements of the banks and shallow areas, Midwest produced a detailed 3D Digital Elevation Model (DEM) for engineering analysis.

The results

The survey delivered the riverbed data the client needed for its ongoing erosion and asset protection work, in a river a motor boat could not reach.

“Without the CEE-LINE™ system, completing this survey would not have been possible. This innovative approach allowed us to deliver precise data for our client’s ongoing erosion and asset protection efforts.”

Midwest survey team