|
Ongoing below average rainfall this summer has continued to cause both Glen Lake’s water level and Crystal River’s flow rate to drop. We have had only three measurable rains since the first week of July. The last time the water level was this low in mid-September was in 2012, when the lake level fell another 2.2” before rainfall in October.
The Glen Lake Association regularly monitors and measures the water level and the river flow rate using sensor technology. A legally binding Water Sharing Management Plan (WSMP), established in 2005 by a court order, specifies a minimum water level for Glen Lake and a minimum flow rate for the Crystal River. This WSMP requires the GLA to adjust the dam gates as necessary to bring the lake level or river flow into compliance.
Until the Glen Arbor area receives sufficient rainfall, the lake level will remain low and possibly drop even lower. The dam adjustments have a limited effect on lake levels because water is lost through evaporation at more than twice the rate of water going over the dam. For example, a ¼” loss of water to evaporation on a warm, sunny day equates to a loss of 5,808,000 cubic feet of water. With a river flow of 25 cubic feet per second, it would take 2.69 days for that much water to go over the dam. Therefore, even significant dam adjustments would only increase the lake level by ¼” in that time and would take weeks to come up to target, if ever. As you can see, rainfall and evaporation are the two key factors determining lake level and river flow. Rain feeds the watershed, which in turn feeds the underground springs that feed our lakes and river.
Lake Level Data Points
- 6/14/24: 596.86’ true elevation above sea level (.02” below target)
- 8/12/24: 596.60’
- 8/21/24: 596.55’
- 8/26/24: 596.52’ (3.84” below target)
- 9/16/24: 596.35’ (4.75” below target)
As we all wait for rain, we urge boaters and swimmers to (a) enjoy the warm, sunny fall days and (b) be safe and pay close attention to water depth throughout Big and Little Glen. Areas which are typically deep enough for boating, jumping or diving, may no longer be so at this time. We especially urge those individuals who are considering illegally jumping off the Narrows bridge to refrain from doing so, as the water level at the bridge is much more shallow than normal.
If you’d like to learn more about the WSMP and how the GLA monitors water levels, please see our website at glenlakeassociation.org/water-levels or send us an email at contact@glenlakeassociation.org.
|
