Skip to main content
U.S. flag

An official website of the United States government

Brett Towler, PhD, PE

Dr. Brett Towler is the Fish Passage Design & Analysis Team Supervisor and Senior On-Site Manager at the Eastern Ecological Science Center's S.O. Conte Research Laboratory in Turners Falls, MA.

Professional Experience

  • USFWS Regional Fish Passage Engineer, Northeast Region 2010-2021

Education and Certifications

  • Ph.D., Engineering, Montana State University-Bozeman

  • M.S., Civil Engineering, Montana State University-Bozeman

  • B.S., Civil Engineering, University of Massachusetts-Amherst

Affiliations and Memberships*

  • Professional Engineer (P.E.), Maine, Board of Licensure for Professional Engineers, Augusta, Maine

  • Professional Hydrologist (P.H.), Surface Water, American Institute of Hydrology, Carbondale, Illinois

Science and Products

Fishway entrance gate experiments with adult American Shad

The goal of this multiyear study was to examine how changes to an upstream fishway entrance impacted the passage rate of adult American shad (Alosa sapidissima). We evaluated a total of nine treatment conditions that consisted of three fishway entrance gate types and three submergence depths (i.e., the water surface elevation of the tailwater relative to the height of the gate crest). Approximatel
By
Ecosystems, Eastern Ecological Science Center

Downstream fish passage guide walls: A hydraulic scale model analysis

Partial-depth guide walls are used to improve passage efficiency and reduce the delay of out-migrating anadromous fish species by guiding fish to a bypass route (i.e. weir, pipe, sluice gate) that circumvents the turbine intakes, where survival is usually lower. Evaluation and monitoring studies, however, indicate a high propensity for some fish to pass underneath, rather than along, the guide wal
By
Ecosystems, Species Management Research Program, Eastern Ecological Science Center

Sensitivity of the downward to sweeping velocity ratio to the bypass flow percentage along a guide wall for downstream fish passage

Partial-depth impermeable guidance structures (or guide walls) are used as a method to assist in the downstream passage of fish at a hydroelectric facility. However, guide walls can result in a strong downward velocity causing the approaching fish to pass below the wall and into the direction of the turbine intakes. The objective of this study was to describe how the ratio of the vertical velocity
By
Ecosystems, Species Management Research Program, Eastern Ecological Science Center

A computational fluid dynamics modeling study of guide walls for downstream fish passage

A partial-depth, impermeable guidance structure (or guide wall) for downstream fish passage is typically constructed as a series of panels attached to a floating boom and anchored across a water body (e.g. river channel, reservoir, or power canal). The downstream terminus of the wall is generally located nearby to a fish bypass structure. If guidance is successful, the fish will avoid entrainment
By
Ecosystems, Species Management Research Program, Eastern Ecological Science Center

Derivation and application of the energy dissipation factor in the design of fishways

Reducing turbulence and associated air entrainment is generally considered advantageous in the engineering design of fish passage facilities. The well-known energy dissipation factor, or EDF, correlates with observations of the phenomena. However, inconsistencies in EDF forms exist and the bases for volumetric energy dissipation rate criteria are often misunderstood. A comprehensive survey of EDF
By
Ecosystems, Eastern Ecological Science Center

Non-USGS Publications**

Towler, B., Hoar, A., and Ahlfeld, D. 2012. Ecohydrology and Fish Passage Engineering: the legacy of Denil and the call for a more inclusive paradigm. Journal of Water Resources Planning and Management 138(2) 77-79. https://doi.org/10.1061/(ASCE)WR.1943-5452.0000185

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

3 men hold a 9 foot tall wood frame upright in a parking lot
link
Two men standing next to a steel I-beam structure in a 10-foot wide concrete flume.
link
Aerial photo of a laboratory campus consisting of 5 main buildings surrounded by trees and located between a canal and a rive
link
Two men plant a pollinator garden
link
Man works sluice pipe in to the tank of a fish transport truck
link
Two men wearing waders drag a net between them to herd fish into a concrete channel.
link
Man stands on grating above a watered flume. Below, American shad school in the pool.
link
Man wearing waders carries live American shad; shad has been implanted with PIT tag in dorsal fin.
link
Two stories of scaffolding assembled with four solar panels on top, facing south.
link
Man uses pliers to secure solenoid assembly to instrument housing on the back of a fish transport truck.
link
3 men pose in front of a 23 foot long boat sitting on a trailer adjacent to a garage
link
Man kneels next to the carcass of a 7.5 ft long Atlantic Sturgeon.
link
Alex Haro clearing flume during lamprey study
link
From the banks of a drained 500 ft wide canal with substation in the background and a 4 foot trap sitting in 10 foot wide riv
link

Science and Products

*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government