While many Borderland residents are concerned now about high water levels, Pelican Lake area resort owners have been thinking about low levels.
The Pelican Lake dam was repaired in 2006 by St. Louis County, and since then local resort owners have complained that the structure has settled 2 inches below its authorized elevation. And that has caused concerns in recent drought years.
The Minnesota Department of Natural Resources could have just repaired the structure, however, staff say a comprehensive impact study is needed before the work begins.
The DNR Waters Division analysis was released on June 11. It was in response to concerns of local Orr residents and property owners on Pelican Lake. These residents met with the DNR and county public works officials last summer to ask for modifications to the dam.
The DNR study noted that the current analysis and a coming shallow lake survey would look at the potential for flood damage to shoreline properties and septic systems. The dam was repaired initially to stop water from bypassing the structure below ground.
The report notes that regardless of repairs, climate conditions will dictate high or low level run out in extreme conditions.
The dam is located just west of the intersection of Highway 53 and Country Road 23. Three separate structures that rise up just a few feet control the water escaping Orr Bay to the Pelican River.
One nearby resident said the wet spring has made the lake and river levels normal, however, the concern is any addition reduction in outflow could endanger the modest river that was just a foot wide during the last drought period.
Climate has a big influence on lake levels, according to Amy Loiselle, DNR hydrologist for the Eveleth area. She said northeastern Minnesota has experienced drought conditions during most of 2007, as well as 2006, 2003 and 2002.
“Low lake level conditions hinder navigation on the lake,” Loiselle said. “High lake levels can cause damage to shoreline and low-lying structures. Pelican Lake, like many northeastern Minnesota lakes, has gone from very low lake levels during the recent drought, to high lake levels due to precipitation received primarily in the fall 2007 and spring 2008.”
The study recommends bringing the dam back to its authorized elevation. As a result, the levels of two bays would be raised and the center bay would be unchanged.
Two options are being considered by the DNR. The first would add 4 inches to the existing run out in two of three bays in the existing structure. This would temporarily raise lake levels about 3.5 inches higher than the existing settled dam.
The second option would add 6 inches to the existing run out in two of three bays to temporarily raise lake levels by about 4.5 inches.
The improved dam would not alter the outflow in the 1-percent chance of a 100-year flood elevation with regard to flood insurance and building requirements.
Increasing the elevation of the run out in two of three bays would result in higher lake levels which follow an isolated summer rainstorm, according to the report. Potential adverse impacts include increased shoreline erosion, septic system impacts and potential flood damage to low-lying structures.
Loiselle said the survey would help determine the lake’s risk analysis and flow. It will look at the impact of water levels on wild rice, shoreline trees and shrubs and other vegetation to see which are more sensitive to “vegetation reflex and chemistry of soil” issues.
The study will begin in July or August when the vegetation is fully grown. The results would help indicate whether flowage easements are needed.
“Plants only like to get so wet, and if they get too wet or too dry then they will die,” said Loiselle. “The same happens with short or prolonged wet or dry times as well.”
The lengthy study will also include a review of public water works rules and input from reviewers on wildlife, fisheries, economic resource and government agencies. Loiselle said as a matter of practicality and efficiency it is best to consider all of the options to just repairing the dam again and then possibly needing to come back in months or years to readdress other avoidable problems.
“The goal is to control low water levels,” she said.
The original dam was built in the 1930s and was repaired periodically over the years. There was at one time an authorization to increase its elevation during a prolonged drought period.
“But we know that people manipulated it over the years and so now the way it is constructed will make it more difficult,” she added. “It is also unlawful to do that.”