Hi, Johnnie: Quick question. I know you can answer this, and I've just gotta know!

How deep is McIntosh Lake? Obviously it is variable, but any general ideas? -- Yvonne

Hi, Yvonne: Twenty-five to 26 feet at its deepest, when full.

Doug Staver, president of the Lake McIntosh Reservoir Company, was kind enough to speak with me not just about the depth of the lake, but how it works.

"It's like a big bowl," he said. "There are no drastic changes in its depth."

Most of the deepest part of the lake is around 20 feet deep, he said.

McIntosh Lake, pictured here in October, is 25 or 26 feet deep at its deepest point.
McIntosh Lake, pictured here in October, is 25 or 26 feet deep at its deepest point. ( Elaine Cromie )

The lake is fed by the Oligarchy Ditch, which enters the lake on its northwest side. Water exits the lake through two 36-inch pipes on its northeast side, at a depth of about 13 feet. Those pipes run for about a mile, parallel to the Oligarchy Ditch, and then feed back into the ditch about a quarter-mile east of Hover Street. Those pipes were installed in the 1800s, Stover said.

So, even if the lake were "drained," there still would be another 7 to 13 feet of water in it. That, Staver said, is called "dead storage."

Now, here's the really interesting part.

Over the winter, the reservoir company installed a flume at the point where water enters the reservoir. Within that flume is telemetry equipment that measures the amount of water flowing into the reservoir. Also, the company has telemetry equipment along the pipes that carry water out of the lake. The equipment at both sites can measure the amount of water flowing in and out of the lake to the cup. Yes, they know how many cups of water flow into and out of the lake.

"There's a considerable amount of water lost to evaporation," Staver told me. "Now we can know exactly how much."

The loss of water to evaporation is shared among shareholders downstream. I understand that the measured amount doesn't include rainfall or runoff from surrounding properties, so that just becomes extra for those downstream.

Yvonne, thanks for that fascinating question. It also led me to an answer for Nathan, who frequently runs around McIntosh Lake and had asked about that flume on the northwest side.