NORTH WEBSTER — Webster Lake Conservation Association is asking the court to settle a dispute with the Indiana Department of Natural Resources concerning the nearly 200-year-old dam.
A complaint was filed in Kosciusko Circuit Court on Feb. 7. The latest inspection states the DNR wants the association to buy two homes near the dam, create a new spillway, remove trees, replace deteriorated concrete, do a geotechnical investigation, a hydraulic study and hire an engineer to evaluate the need for a new dam. However, the complaint alleges April 11, 1996, the association and DNR entered into an agreement which states it is mutually agreed the association has the responsibility for the general maintenance of the outlet control structure to maintain, as near as possible the legally established level of Webster Lake and the responsibility for construction or repair of the outlet control structure remain with the DNR.
The dispute came about following a 2017 visual inspection of the dam by the DNR.
The association is asking the court to declare its rights and the obligations of the DNR under the agreement requiring the DNR to undertake reconstruction and repair.
The main document included in the complaint is a 52-page Oct. 12, 2017, dam inspection report by Traci M. Powell, engineer for the IDNR-Water. That inspection gave the dam acceptable ratings for the upstream slope and seepage. Deficient or poor ratings were given for the crest, downstream slope, principal spillway, auxiliary spillway and maintenance and repairs.
Among the comments on those areas receiving deficient or poor ratings included trees, brush and briars; animal burrows, homes built in/on the dam; deterioration, inadequate freeboard, the spillway being too small, obstructed flow, deteriorated concrete and yard embankments.
Powell noted in the overall condition, the dam is poor and recommended removing trees and/or brush from the entire dam and within 25-feet of all concrete structures, a geotechnical investigation conducted to evaluate the stability of the dam, a hydrologic study to determine required spillway size, prepare plans and specifications for an adequate spillway for overtopping protection since the downstream is developed and development of an emergency action plan. It was also recommended the owner’s professional engineer evaluate the need for current dam design standards and recommended repairs.
This inspection document additionally stated “it is recommended that the Webster Lake dam’s hazard classification be upgraded from significant hazard to high hazard … the outcome shows multiple residential and business structures at high risk during a catastrophic breach of the dam. Those at greatest risk with little response time are those low-lying homes in and between the dam and SR 13, many more at risk downstream of SR 13 to James Lake… . The spillway capacity appears to be inadequate … the hydraulic capacity of the primary and secondary spillway is undetermined. It is recommended to investigate and assess the hydraulic capacity of the current spillways … dam owner consider overtopping protection when a future flooding occurrence happens.”
The document notes a description of the repairs made in the past, including a brief history of the dam. It notes there have been several modifications over the decades and DNR Water funded a rehab project due to an agreement between the DNR and association signed in 1993. “DNR has the responsibility to ‘repair’ the ‘outlet control structure.’”
Documents note the dam underwent extensive surficial rehab work in 2011-12 where rebuilding of some of the east spillway retaining walls, demolition of a deteriorated fish ladder and replacement of a catwalk and slide gates were made, along with the west spillway headwall being recast in concrete and a slide gate replaced.
However, the inspection document notes the 2011-12 project did not address all the recommendations from the previous visual inspection. “Part of the ‘all’ would include removal of the two homes between the east and west spillways. The embankment is the responsibility of the Webster Lake Association. However, many items were addressed with the recent rehab … .”
Among the comments is maintenance and repairs should be focused on stabilizing the embankment and adding overtopping protection where it can be added on the embankment. The comments also include mentioning the Wilmot Pond dam, upstream in the watershed, is a significant hazardous dam with limited capacity. This dam as well as the culvert at the backwaters are bottlenecks in the watershed system.
“While no probable failure mechanism has been assessed, it seems likely that the case for the two most probable are: overtopping and failure of the basement wall of the nearest residential structure to the lake.”
The inspection document further notes “overtopping is a common and possible failure mechanism for this dam … this dam has little freeboard and minuscule flood storage available … minimum of two homes in the embankment. The most westerly home closest to the smaller, secondary spillway is closest to the lake. In the most recent high water event, operators reported observing water trickling from the home’s basement. There should be concern in the future that this concrete block wall could give way if there is enough hydrostatic pressure pushing laterally.”