Project Background

In 2003 Hillier & Associates, Inc. (HAI) received a matching grant from the Maine Technology Institute to support the research and development of a scientific methodology to acquire accurate lake depth information. HAI spent the summer field season of 2003 perfecting its methodology of lake bathymetry while systematically mapping seven lakes in central Maine.

HAI acquires lake-depth data using multi frequency sound waves (SONAR) at a rate of once per second and simultaneously matching each data point with location coordinates gathered on a boat mounted differential global positioning system (GPS) and taken at a speed of 1 MPH to 20 MPH. The resulting data, collected on a laptop computer, is accurate to 0.0 meters in the vertical plane and 2.0 meters in the horizontal plane.

Bathymetric lake surveys typically include 100,000 to 300,000 data points (about 25 per acre) and require several days to several weeks to complete. Once compiled into a geographic format, these surveys produced the most accurate bathymetric lake maps ever produced in Maine. A Maine Certified Geologist supervises all bathymetric surveys and a Maine Registered Engineer supervises all data sets and graphic presentations.

The contoured depth information is presented using vivid colors varying from red in the shallowest water to dark blue in the deepest holes and basins. High-resolution black-and-white aerial photographs provide the backdrop for each lake map. (Customized backgrounds are also available.)

Our graduated color maps are merely a demonstration of the potential uses for this technique. Other uses could include: identifying fishing locations and habitat; calculating lake volume and flushing rates; and computing the volume of dredge materials.

HAI’s maps have the potential to aid in the discovery of feasibility methods for water quality improvements; origin, age, and composition of underwater landforms; shape or exposed terrain following dam removal; and the impact of pollutants entering a water body.

HAI’s hydrographic, bathymetric, and geologic mapping services are available to all public, private, and non-profit organizations. Please contact us to purchase maps or discuss projects.