Crews begin drilling for samples at Little Falls Lake dam
A primitive roadway crossing a portion of the Willow River represents the latest effort toward a new dam along the waterway.
The crossing was erected over the past couple weeks at Willow River State Park to allow an engineering firm to conduct geotechnical work near what remains of the Little Falls Lake dam. Sections of the crossing were washed away after heavy rains battered the area over the past week, though those portions are expected to be refilled, providing passage for drilling equipment.
Willow River State Park Manager Aaron Mason said crews will spend the next few weeks boring deep into the bedrock and taking samples.
The samples will give engineers a cross-section of what lies beneath and will be critical to understanding “what the dam is going to be constructed on,” he said.
Crews arrived Monday and began drilling on Tuesday.
Mason said the sample testing will occur at multiple spots spanning the waterway.
“We’ll be able to see if there are any underlying things that need to be addressed,” he said.
The effort is the latest step in a multi-year process to replace the Little Falls Lake dam, a massive portion of which was torn out about a year ago after Department of Natural Resources officials concluded the aging structure represented a safety hazard in the face of heavy flooding.
The DNR called for Little Falls Lake — a manmade impoundment — to be drained as part of the process.
The lake bed, now covered with vegetation, has retreated to a narrow Willow River waterway.
Plans, however, call for the lake to be restored once a new dam is erected. Lawmakers in 2015 allocated $8 million for the project, the construction for which is tentatively set to be done in August 2019. The lake would be refilled by March 2020, according to a DNR timeline.
The project is in the design phase, which Mason said will take shape over the next few months. The timeline calls for the Department of Administration to review and approve designs in March 2017.
“We’re on schedule,” Mason said.
Most of the dam has been demolished and hauled away. The remaining portion will remain in place until a contractor for the project is selected and approved by the Building Commission, Mason said.
Fine-grain sediment continues to flow over the dam area, he said, adding that some has been scooped out. That effort will continue, Mason said.
“We’re looking to do that on a bigger scale” before winter, he said.
While the park did see a downtick in the number of campers in 2016, Mason said overall park attendance has been up over 2015 numbers; the upper falls continue to be a big draw for day visitors, he said.