There are many major rivers flowing through the Pacific Northwest. Like others around the country, they are outfitted with various dams and reservoirs that are used to control their movements, provide energy and maintain drinking water supplies for those living around them.

The U.S. Army Corps of Engineers (USACE) plays a big hand in managing and maintaining the structures that corral these rivers. Of significance for engineers with the USACE’s Walla Walla District are the Columbia, Snake and North Fork Clearwater Rivers.

Along these waterways, engineers with the district oversee conditions in reservoirs that are linked to summer releases of dams. Typical impacts that managers see have to do with fluctuations in water temperatures, which can affect the aquatic life, like fish, that live downstream.

To keep tabs on these reservoir temperature changes, engineers with the Walla Walla District worked with NexSens Technology to obtain the necessary monitoring equipment, including thermistor strings and data loggers.

Keeping tabs on reservoir conditions

Managers at the Walla Walla District selected NexSens T-Node FR Thermistor Strings for monitoring water temperatures in profile. These were deployed in reservoirs along certain rivers with the goal of evaluating the temperature structures of the reservoirs as they related to summertime dam releases.

Because of their fast response time, the T-Node FR Thermistors were ideal for capturing the quick changes that can come following a large influx of water. These were deployed at the depths that the USACE engineers requested, down to 35 meters in some cases, and connected to NexSens OEM Data Loggers. In this type of setup, data loggers are typically mounted directly onto a dam or at an area downstream using a pole mount.

All reservoir temperature data collected by the loggers route directly to the USACE’s internal data system for viewing and processing. This is accomplished through direct connection from data loggers to the Army Corps’ internal web infrastructure.


X2 Environmental Data Logger

The NexSens X2 Environmental Data Logger offers the latest in real-time monitoring technology with wireless communication, large plug-and-play sensor library, and ultra-low power consumption.

NexSens T-Node FR Thermistor String

The NexSens T-Node FR thermistor string provides high precision temperature measurement in an addressable and connectorized assembly.