DELHI — The health of the environment will be subordinate to the interests of several hundred Delaware County disaster victims if the state helps fund the rebuilding of the Lake Delhi dam.
That is the contention of environmental groups opposing a $5 million appropriation over two years to help pay the estimated $11.9 million cost of rebuilding the dam, which failed during Maquoketa River flooding in July 2010.
Rebuilding the dam “would in effect be putting the needs of the few ahead of the needs of the many,” said Iowa Whitewater Coalition spokesman Peter Komendowski of Waterloo.
Calling the Delhi impoundment a sediment trap, members of Iowa Rivers Revival predict a chronic demand for state funding to pay for dredging.
The Department of Natural Resources, from whose budget the proposed allocation would come, agrees that the environment would be better served by a free-flowing river than by an impoundment.
Dams slow the impounded river’s natural flow, causing sediment that would normally be transported downstream to settle out in the impoundment, said Nate Hoogeveen, the DNR’s river programs manager.
The increased silt deposits degrade the lakebed’s value as habitat for fish and other aquatic animals, decreasing habitat complexity and species diversity, he said.
A connected river that is not disrupted by dams will support more species of fish that will grow bigger and faster and be less susceptible to toxic spills and low dissolved oxygen, he said.
“But what is better for the river does not always rise to the top in public policy matters,” Hoogeveen said.
While the Legislature and the governor will decide the matter, “we have an obligation to provide input on how money from our budget is spent,” said Chuck Gipp, DNR deputy director.
Iowa’s lake restoration guidelines would have to be set aside to support the rebuilding of the Lake Delhi dam with funds from the DNR’s lake restoration budget, said Mike McGhee, the DNR’s lakes and rivers project coordinator.
The DNR, he said, has four major concerns with the rebuilding plan: the sustainability of the lake, given its 500-to-1 watershed-to-surface-area ratio; shortcomings in the treatment of wastewater in what the DNR describes as “Iowa’s largest unsewered community”; the plan’s absence of a provision for fish passage; and inadequate public access.
Lake Delhi, which had 448 surface acres, drained a watershed of 223,630 acres. That 500-to-1 ratio is comparable to the 528-to-1 average ratio of the Corps of Engineers flood-control reservoirs in Iowa: Coralville, Rathbun, Red Rock and Saylorville.
It is about 13 times higher than the 38-to-1 statewide average ratio for state- and county-constructed lakes. For the two constructed lakes in the Cedar Rapids-Iowa City area — Pleasant Creek and Macbride — the ratios, respectively, are 5-to-1 and 20-to-1.
Leaders of the rebuild effort maintain that the lake is sustainable without frequent dredging.
The 2006 dredging, for which lake residents incurred $2.2 million in debt, was the first since the lake was impounded in 1928, said Steve Leonard, president of the Lake Delhi Combined Recreational Facility and Water Quality District, the lake area’s official governing body.
“One time in 80 years seems like a good investment,” he said.
While the lake district had planned to re-dredge portions of the lake after 2008 flooding nullified much of the 2006 project, that second dredging, which was never accomplished, would not have been necessary to maintain navigation, said Pat Colgan, a retired civil engineer and volunteer coordinator of the rebuild effort.
The stretch of the Maquoketa River that includes the former lake, like many other Iowa water bodies, is designated by the Environmental Protection Agency as impaired by bacteria.
While it is difficult to pinpoint sources of bacterial contamination, the DNR believes the elevated level is at least partly attributable to the more than 800 septic systems serving residences along the former lake.
Environmental specialist Mike Wade, who works out of the DNR’s Manchester office, said the agency has long been concerned about effluent, or outflow, from Lake Delhi septic systems contaminating groundwater.
“Many septic systems are just too close to wells,” he said.
Although Wade has seen little evidence of septic systems discharging into the river, “contaminated groundwater contributes to the river,” he said.
DNR water-quality specialist Mary Skopec said tests conducted in 2006 on Lake Delhi yielded many readings above the safe swimming standard for bacteria. Those readings, she said, “were not that much out of line with readings for the rest of the river.”
Since 2000, several Lake Delhi residents have regularly collected water samples from 10 sites in and around the lake for tests under the IOWATER water-quality program.
During that time, between 300 and 400 samples have been tested for temperature, pH, nitrite-N, nitrate-N, phosphate, dissolved oxygen and transparency, with median results almost always falling within the normal range for Iowa rivers and lakes.
Tests for chloride, which can indicate human and animal waste, also have been conducted on 129 samples, again with median results falling within the normal range for Iowa rivers.
Bob Galiher, 72, a Lake Delhi resident for 40 years and an IOWATER volunteer since Lake Delhi testing began, said his impression of the test results is that they are “pretty acceptable and surprisingly good.”
Lake Delhi residents, he said, “are concerned about water quality and committed to do the right thing.”
Delaware County water and sanitation administrator Dennis Lyons, while acknowledging that many wells do have high bacteria counts, said he has “never heard of anyone getting sick from swimming in the lake or drinking from the wells.”
As for the DNR’s insistence on provisions for fish passage, the lake district’s Leonard said, “The Legislature needs to weigh the costs and benefits of this luxury.”
Because of the rebuilt dam’s 40-foot height, an inclined fish ladder with enough resting pools to get fish over the top would cost between $700,000 and $800,000, Colgan said. Because good populations of game fish already inhabit upstream and downstream sections of the river, the fish ladder would do little good, he said.
Leonard said the lake district is more than willing to work with the DNR on improving public access, which is already available at two county parks and a marina.
In addition to the hoped-for $5 million in state support, lake residents have committed to $6.1 million in general obligation bonds and have secured about $1.7 million in private pledges and donations. The Delaware County supervisors, which have yet to commit to the rebuilding, are considering a $3 million bond issue.
The Delaware County supervisors will hold a public meeting on a proposed $3 million bond issue to help rebuild the Lake Delhi dam. The meeting is scheduled for 7 p.m. Feb. 29 at the Delaware County fairgrounds.