Carroll Cave Stream Flow Project – 2023 Annual Report

Another year is gone and done. It is time to collect and review data from the Carroll Cave Stream Flow Project.

This year I have a new version of the graphing software. It allows multiple plots on one page with different Y-axis scales for each. This allowed me to plot both water depth and matching water temperature. Looking at the plots, it is very obvious that the water temperature changes whenever there is a flood. In winter the temperature goes down and in summer it goes up. This shows that the cave takes on water very rapidly. The incoming water does not have time to acclimate to normal cave temperature before it gets to the data loggers.

2023 did not see any major floods. There were two minor floods. “Minor” is a relative term. If you were in downstream Thunder River on March 25, it was a major flood!

In late March Thunder River at the ladder rose from the normal depth of just under a foot to around 3 feet. The river below Thunder Falls rose from about 15 inches to over 14 feet in that event. The data from this event proves again that downstream Thunder River floods before upstream Thunder River. Major floods in upstream Thunder River are the result of downstream Thunder River getting stopped up and backflooding.

From mid-July to late August there were three more floods. Thunder River rose to about 1 3/4, 2 3/4 and 2 1/4 feet on those occasions. Below Thunder Falls the effect was rather muted with a maximum of just 3 feet.

The rainfall data shows quite a bit of rain from mid-July through August, as showin by the vertical sections of the graphs. There was rainfall in March around the time of that major flood, but not as much as in August. That seems a bit odd since the March flood was much higher than the August floods.

The plan for next year is to continue as usual. The data logger at Thunder Falls needs a battery replacement which is in progress as I write this. As a result the graphs for 2024 will be missing a month or maybe two of data from that logger.

The ZIP file attached to this post contain all of the files used to create this report. The files with .hobo extension are exactly what comes off the data loggers. Each of those was exported to a .csv file. I combined the .CSV files to produce RawData files. The RawData files contain exactly a calendar year of data, and servered as the source for the graphs.

Hobo files can only be used with HoboWare Pro software. There is a free version of this available at The free version has significant limits on functionality, but it can read the .hobo files and produce graphs.

Water Depth is a calculated value based on water pressure, barometric pressure and the density of water. The formula is (water pressure – barometric pressure) * 2.0373.

If you have any questions or see something that needs to change, let me know.

Bill Gee