Hydrographic Surveying and Field Services
Understanding the movement and deposition of sediment in water bodies provides a critical foundation for supporting mapping and modeling projects for reservoir yield estimates, dredging feasibility studies, scour around infrastructure, and related projects. Aqua Strategies provides hydrographic surveying and field services in both freshwater and coastal environments to support navigation, to enhance the understanding of coastal hurricane impacts, assess the condition of submerged infrastructure, measure sediment thickness, assess the feasibility of dredging, and to evaluate the capacity of reservoirs. Aqua Strategies deploys leading-edge technologies, including single beam, multi-frequency and multi-beam acoustics, and coring devices to collect bathymetry, underwater imagery and sediment thickness for developing maps and associated models. Aqua Strategies has completed hydrographic surveys and field data collection for multiple clients including: US Army Corps of Engineers; Trinity River Authority; Brazos River Authority; Texas Water Development Board; many private clients; and under subcontract to multiple large engineering firms.
Project: Lake Whitney Hydrographic Survey
Client: U.S. Army Corps of Engineers Institute for Water Resources
Date: 2019
Keywords: Hydrographic Surveying; Water Planning; Water Quality; Sediment Modeling; Decision Support Tools; Data Collection; Data Analysis; Data Visualization
Aqua Strategies performed a volumetric and sediment survey of Lake Whitney, a large reservoir (23,215 surface acres) in the Brazos River watershed, to determine the impact of accumulated sediment on the volume of water stored by the lake. This was the first study to measure the sediment thickness and lake volume at the same time, making the results particularly reliable for future water planning.
Bathymetric data were collected by Aqua Strategies personnel using a multi-frequency sub-bottom profile echosounder (200 kHz, 50 kHz, and 12 kHz), which was integrated with GPS and motion sensing equipment for improved accuracy of readings. Sediment cores were collected at multiple locations for quality assurance purposes and to verify sediment accumulation measurements from the echosounder.
Aqua Strategies selected a state-of-the-art software program (HyPack) to validate and process the 950,000 data points collected in the field. In addition, Aqua Strategies produced data visualization graphics illustrating the bottom surface (both pre- and post-impoundment), sedimentation rates and lake capacities over time.
As a result of the study, the U.S. Army Corps of Engineers and Brazos River Authority can better determine the future capacity of the lake to provide the important functions of flood control, water supply and hydropower generation.
