November 13, 2013 - Goodrich- The village dam is leaking.
The seepage was realized after a village DPW worker and others reported sinkholes in the soil embankment just east of the spillway. There were at least two instances of where the soil gave way under foot. There were no injuries.
The sinkholes are an indication of a breach suspected by village officials and dam engineers from the century-old dam.
Jason Kenyon, engineer from WadeTrim, attended the village council meeting on Monday night to address escalating issues with the village dam. A cost report will be presented at the Dec. 9 village council meeeting.
"There are issues with the embankment of the dam," said Kenyon. "Ground water is migrating around the dam. We are not sure of the condition (of the dam). While there are long-term replacement considerations of the dam in the future, there are short term fixes that need to be addressed."
Kenyon suggested a proposal for a series of tests including geotechnology studies and soil boring around the dam.
"We can only tell so much from the surface," he said. "There's a lot going on we can't qualify—there's big voids under the dam."
Jakki Sidge, village manager, said there are no quick fixes with regard to the dam.
"The top need will be to determine where the water is flowing through the dam," she said. "We've had sink holes before, but now its gone from ankle deep to knee deep. The crevice has changed in the past few months."
The needed repairs to the aging structure are among several that require attention by the village.
In the spring of 2012 the Michigan Department of Environmental Quality inspected the century-old village dam and required some significant repairs to the structure. Then, only three of the five wooden flood gates, which move up and down to regulate the amount of water and the level of the mill pond, were operational. Two of the gates remained stationary. The state inspector required the village to remove the two stationary gates and replace with moveable gates. Following the approval of the MDEQ, the village DPW cut about three feet off the top of the two eight foot stationary watergates, which will allow the necessary flow over the dam in the event of a major water event. Those top sections of the watergates were left in place and will be removed if necessary.
The need, say MDEQ officials, is to allow sufficient water to pass through if heavy rains were to occur. If the dam can be modified to meet the requirement for water flow is the MDEQ's concern.
According to the Association of Michigan Dam Safety, of the 1,019 state regulated dams, 88 have a high hazard potential, 132 have a significant hazard potential and 799 have a low hazard potential.
"The Goodrich Dam has a significant hazard potential," added Keyton. "That's one level below the worst."
According to the AMDS, a significant hazard potential means that a failure may cause damage limited to isolated inhabited homes, agricultural buildings, structures, secondary highways, short line railroads, or public utilities, where environmental degradation may be significant, or where a danger to individuals exists.
"The cost of the study would be less than $75,000," he said. "I think it's worse than we think. The cost will be figured on what is the cost to relieve the pressure on the dam."
Village resident Norm Bass was not a supporter of spending money to determine the extent of the leak.
"Why do we need to spend money on this?" he said. "We know it leaks. We know there's a problem."
Bass suggested utilizing steel sheet piles, interlocking sections that are driven in the ground to support excavations or soil removal.