by Skip Via
skip@westvalleynaturalists.org
Here is a quick end-of-summer hydrology snapshot as of 9/18/23. (Compare to July 2023.)
| Rainfall YTD | -3.4” from average |
| Flathead Lake Level | -36” (3’) from full pool |
| Hungry Horse Reservoir | -168” (14’) from full pool |
| Streamflow, Flathead River | -80 cfps from normal |
| Snowpack | n/a |
| Snowmelt | n/a |
Despite a welcome August rain (21st wettest August on record) from the remnants of Cyclone Hilary, most of the Flathead Valley is still experiencing “moderate drought.” As of this writing, we’re experiencing the 6th driest year in 129 years of record keeping. Lake levels remain at historic lows. Streamflow in the North and Middle forks of the Flathead River are at “historic lows.” Streamflow in the Flathead River is somewhat mitigated by release from the Hungry Horse dam, which by regulation must maintain a minimum streamflow level for water leaving the dam. That release is causing the water level at the dam to drop.
Local lakes and ponds have benefitted from the August rain. Water levels are noticeably higher than they were in July, but are still far below average levels. Some of this increase is due to runoff, and some is due to the raising of the water table through replenishment of the shallow aquifers that underlie most of the West Valley area.
Compare this image to the image at the top of this page and to the image from the Hydrology Snapshot, July 2023.
The other noticeable effect of the August rain event was the immediate and dramatic greening up of local flora. And lawns.
