Continuous stream stage and discharge

Stage Measurements

The KWRC installs and maintains steam gaging stations in wadeable streams. KWRC stations are equipped with staff gages and stilling wells with Solinst Levelogger Edge pressure transducers coupled to a Solinst Barologger Edge. Stream stage is digitally recorded at specified intervals of time and barometrically compensated once downloaded. Data at each station is downloaded on a monthly basis to ensure accuracy of data and maintenance of any equipment installed in the field. Stations are additionally checked during periods of flooding and low flow to ensure the integrity of the stations.

Rating Curves

Rating curves are developed for each gaging station to convert stream stage readings into discharge rates. Manual flow measurements using a Marsh-McBirney FlowMate flow meter are taken at 60% of total stream depth for streams 0.3 - 0.25 feet deep and at 20% and 80% of stream depth for streams deeper than 2.5 feet in order to accurately estimate average flow through the stream channel. Discharge is determined for each interval then totaled to get entire stream channel discharge. Discharge rates are plotted against stream stage levels to develop a rating curve. Manual stream flow measurements follow protocols outlined in the USGS Discharge Measurements at Gaging Stations publication. Rating curves are checked every four weeks, after flood events or channel alterations and rebuilt as needed.

Continuous water Temperature

Water temperature is measured using submersible Onset Computer Corporation Optic Stowaway TidBitv2 data loggers. Temperature loggers are installed based on the EPA’s Best Practices for Continuous Monitoring of Temperature and Flow in Wadeable Streams. Loggers are housed in PVC units and anchored to the stream bed or other large object such as a rock, tree root or cement wall. Temperature is recorded at specified time intervals and is downloaded every four weeks. Loggers are additionally checked during low flow periods to ensure they are fully submersed in the stream or spring.

Continuous Groundwater Elevation

Groundwater wells are equipped with In-Situ Level Troll 500 pressure transducers. Water surface elevation is recorded at specified time intervals and downloaded every four weeks. A water level meter is used to manually check and calibrate the Level Trolls during data downloads.

Quarterly Water Quality Sampling

The KWRC offers quarterly water quality sampling during baseflow conditions. Field collection protocols are based on the USGS National Field Manual for the Collection of Water-Quality Data. Both preserved and un-preserved samples are collected to determine the concentration of physiochemical parameters and dissolved and total metals. Water samples are analyzed by the Pennsylvania Department of Environmental Protection Analytical Laboratories. Any coliform analysis of spring water samples is conducted by the University Area Joint Authority laboratory. At the time of sampling, direct measurements of dissolved oxygen, water temperature, conductivity and pH are taken using YSI meters. All meters are calibrated daily during sampling.

For more details on monitoring methods and services please contact Lexie Orr, KWRC’s Water Resources Specialist at lexie@keystonewaterresources.org