Water worries rage on
Dan McIntosh with SIRWA explains how an Arbor Valley Lake project isn’t ideal
“Whiskey is for drinking; water is for fighting over.”
It is believed Mark Twain uttered these words, and 200 years later, they still ring true, even in Clarke County.
At the Clarke County Reservoir Commission (CCRC) meeting Feb. 14, Dan McIntosh with Southern Iowa Rural Water Association (SIRWA) addressed concerns he’s heard about the CCRC’s Squaw Creek Watershed ongoing project, which could provide a water supply for Osceola and SIRWA with an 816-acre lake that could provide 2.2 million gallons of water per day.
The total project cost for the reservoir in the CCRC Squaw Creek Watershed is estimated at $35.5 million. Funding the project includes many sources, especially local-option sales and services tax (LOSST).
Arbor Valley Lake expansion
McIntosh said he’s had several phone calls during the past couple of months about at expansion project at Arbor Valley Lake and why the CCRC isn’t looking more into it as a water source instead of the CCRC project.
There is a public opposition to the CCRC water project, and many of those people in the opposition favor an expanded water project at Arbor Valley Lake.
McIntosh said he’s not an engineer, but this is his best clarification of the situation at Arbor Valley Lake.
He provided a map of the area from Google Earth, which put Highway 34 as the high line in the map.
“I knew however big of a lake it was, we could not go over Highway 34 because it was going to cost a bunch,” he said.
The expanded Arbor Valley Lake project would be approximately 606 acres.
“That’s really about three-fourths the size of what we have right now,” McIntosh said.
A yellow stripe on the map is a 400-foot buffer zone from the lake pool, a standard that is set by the Department of Natural Resources (DNR).
McIntosh said eight homes would be affected in the buffer zone.
“I’ve heard it said several times that we should be moving to Arbor Valley Lake because no homes will be affected,” McIntosh said. “Well, that’s not right at all when you actually look at the facts.”
The drainage area with the expanded Arbor Valley design is 9,577 acres. The CCRC has 16,500 acres.
Then, there’s the drainage area to pool area (DAPA) ratio. McIntosh said he’s been involved with Three Mile Lake in Union County, and SIRWA was involved with Lake Icaria in Adams County, as well as Little River by Leon.
“All of those had a really close 20 to 1 ratio, and that’s what they’re looking for. They want 20 acres in the upland area to fill up one acre of lake,” he said. “So, that’s where you get this 20 to 1 ratio, and it’s a very important ratio because whenever we’ve got a drought we need to be able to fill that lake.”
McIntosh said he’s received comments from people asking why a ratio of bigger than 20 to 1 isn’t ideal.
He said, right now, the lake by Winterset has a 50 to 1 ratio, and it’s actually a problem because whenever it rains a little bit in the drainage area, it floods the lake.
“The lake is so full of sediment right now because they can’t get the upland treated enough,” McIntosh said. “It’s just such a huge area.”
The CCRC water project has a DAPA ratio of 20.2 to 1. The Arbor Valley Lake has a DAPA ratio of 15.8 to 1.
Raw water line
When it comes to the length of the raw water line (water treatment), McIntosh said he’s heard people say the raw water line would be “so much closer if we went with Arbor Valley.”
The length of the raw water line from the CCRC lake proposed intake structure to existing treatment plant, following existing roads, would be six miles.
The length of the raw water line from the Arbor Valley proposed intake structure to existing treatment plant, following existing roads, would be 4.7 miles.
However, this would require the need to bore underneath Highway 34 and the Burlington Northern Santa Fe railroad line. McIntosh said it would be an expensive undertaking, even though it’s shorter in miles.
The water yield for the CCRC lake is 2.2 million gallons per day.
McIntosh said since the lake and drainage pool would be smaller at Arbor Valley Lake, it would probably be less than 2.2 million gallons per day.
At the CCRC lake, the dam may be raised at a future date to give the lake a 3 million gallons per day withdraw instead of the current 2.2 million gallons per day.
At Arbor Valley, the drainage area includes parts of Highway 34, Interstate 35 and the railroad line.
“When we looked at this years and years ago, that was one of the big things we didn’t want to do is have those three entities that have a lot of traffic draining into our watershed,” McIntosh said.
He added, he’s been told be a few engineers, if the Iowa Department of Transportation would even allow an Arbor Valley Lake project, if the dam failed, it could wash out Interstate 35.