As the recovery from the catastrophic flooding of 2018 moves into its fifth year, USDA-NRCS has now published their draft proposal to decommission the PL-566 flood control dams in the West Fork Kickapoo and Coon Creek watersheds. The document is referred to as a Draft Programmatic Environmental Impact Statement (PEIS).
There are a total of 14 flood control dams in the Coon Creek Watershed, and 10 dams in the West Fork Kickapoo River Watershed. USDA-NRCS proposes decommissioning of all Coon Creek dams, and nine of ten flood control dams in West Fork Kickapoo, and to rebuild the Jersey Valley Dam.
In West Fork Kickapoo, during the rain event that caused the record 2018 flood, as much as 11 inches of rain are believed to have fallen over a six-hour period in the headwater areas. This caused the Pilot Mlsna and Jersey Valley dams to breach, and two other structures to overtop.
In Coon Creek, the same rain event caused three dams to breach (Korn, Bilhovde and Luckasson), and two to overtop. The dams breached along the interface between the earth-fill and bedrock abutments. Each breach extended full depth to the valley floor, but thankfully no one was injured or killed.
Investigation of the breaches revealed that seepage flow through a highly fractured sandstone foundation where the dams abutted the hillside when the impoundments behind the dams were full contributed to the failures. NRCS and LaCrosse, Monroe and Vernon counties are concerned that a similar vulnerability exists in the remaining dams that did not breach.
Decommissioning the dams will involve excavating a notch in each dam large enough to pass the 100-year frequency, 24-hour frequency storm without stormwater impoundment. The existing rise structures, cantilever pipe outlets, and plunge pools will be removed. The principal spillway pipes will be removed or grouted shut. All slopes will be shaped to a stable and safe angle of repose. The accumulated sediment collected behind the dams will be left in place and vegetated as needed. Accumulated sediment will evacuate over time.
Next steps
Hard copy of the ‘Notice of Availability’ (NOA) of the draft proposal were mailed to the adjacent landowners and cooperating Federal and state agencies on Friday, December 15.
NOAs will also be published in the local newspapers for a period of three weeks.
The NOAs will be posted on the EPA NOA Federal Register on Friday, December 22, 2024. Public comments will be accepted through Tuesday, February 20, 2024.
Town hall meetings will be held in Coon Valley and Cashton to discuss the contents of the documents. The meetings will occur:
• Coon Valley American Legion Hall, 12-2:30 p.m., on Thursday, Jan. 18, for a public meeting on the draft Plan-PEIS for Coon Creek.
• Cashton Community Hall is reserved for 4-6:30 p.m. on Thursday, Jan. 18, for a public meeting on the DRAFT Plan-PEIS for West Fork Kickapoo.
Information/comments
To obtain a copy of the proposal, go to the project website at: www.wfkandccwatersheds.com. Copies of the DRAFT PEIS are also available at the LaCrosse, Monroe and Vernon County Land Conservation Department offices.
Comments can be submitted electronically at the project website, or by hard copy delivered by U.S. mail or hand-delivery to:
Pete David, Project Manager, Sundance Consulting, Inc., 10400 Academy Road NE, Suite 200, Albuquerque, New Mexico, 87111.
All written comments will be posted without change, and made publicly available on the project website. Written comments become part of the public record associated with this action. All information submitted with comments, such as address, phone number, e-mail address and any other personal identifying information, will also be part of the public record. Anonymous comments will not be considered.
All submissions from organizations and businesses, and from individuals identifying themselves as representatives or officials of organizations or businesses, will be made available for public disclosure in their entirety.
Jersey Valley proposal
Because of its recreational value, the draft proposal calls for the reconstruction of the Jersey Valley Dam about 1,000 feet downstream of the existing, failed structure. The replacement structure would be a multi-purpose dam for flood control, public recreation and public fish and wildlife. It would be classified as a High Hazard structure because a breach may cause loss of life and significant property damage.
Sediment analysis
Eight sediment samples were collected between Dec. 13-20, 2021 from the impoundment areas behind dams in both watersheds.
Due to cost, NRCS selected four dams (two in each watershed) in consultation with the county conservationists. The sites were selected because the team suspected they might have higher contamination or nutrient levels due to industry within the watershed and landscape position. They took samples between 0.5-1.5 feet deep, and 4-5 feet deep.
“We will test sediments behind all of the dams if a final decision is made by the counties to decommission them,” USDA-NRCS State Conservation Engineer Steve Becker explained.
Analysis of the sediments behind the selected dams revealed:
• no arsenic
• no organochlorine pesticides
• nitrate was detected in one of the eight samples with a concentration of three milligrams-per-kilogram (mg/kg)
• ammonia (as nitrogen) was detected in all sediment samples, with concentrations ranging from 230 to 11,000 mg/kg, with the highest level coming from a sample at the Jersey Valley Dam
• phosphorous was detected in all samples, with concentrations ranging from 442 to 753 mg/kg
• six of eight samples had detections of PFAS compounds, with no detections of PFBS, PFOA or PFOS; PFOS-Total was detected in five of the eight samples, with concentrations ranging from 52 to 220 nanograms-per-kilogram (1 ng/Kg = 1 ppt (parts per trillion) = 0.000001 ppm).
EPA drinking water standards are available for arsenic and total nitrates (nitrate+nitrite). In December of 2019, EPA issued interim recommendations for addressing groundwater contaminated with PFOA and PFOS, including clean up guidance for federal cleanup programs. The guidance recommends using a screening level of 40 ppt to determine if PFOA and/or PFOS is present at a site and may warrant further attention.
The DNR has established a soil residual contaminant level (RCL) for both PFOA and PFOS using the EPA’s regional screening level (RSL) web calculator and following the procedures in Wisconsin Administrative Code NR 720.12. The non-industrial direct contact RCL for PFOA and PFOS is 1.26 mg/kg (1,260,000 ng/kg) and the industrial direct contact RCL is 16.4 mg/kg (12,600,000 ng/kg). There are currently no groundwater protective soil limits, and water quality values for rivers and streams are in the process of being established (WDNR, 2022).
“Based on our early discussions with the consulting team, the PFAS analytes in soil residual (sediment deposited behind the dams)were not excessive by state or federal standards,” USDA-NRCS State Conservation Engineer Steve Becker said. “However, PFAS is outside our area of expertise. The EPA and DNR were brought in as cooperating agencies, and will be reviewing the data more closely during the DRAFT PEIS comment period.”
Cultural resources
As required, a ‘Cultural Resource Investigation for the West Fork Kickapoo River Watershed in Monroe and Vernon Counties’ was undertaken. Megan Daniels, Seth Schneider and William Balco of UW-Milwaukee Cultural Resource Management undertook the study and produced the report.
West Fork Kickapoo
From June to September 2023, UWM-CRM personnel conducted Phase I cultural resource investigations at nine flood dams in the West Fork Kickapoo River Watershed in Monroe and Vernon Counties. The cultural resource investigations were conducted on behalf of Vernon County, as the dams are located in Vernon County, and the National Resource Conservation Service (NRCS), an agency of the United State Department of Agriculture (USDA).
According to the report:
“Three new archaeological sites were identified at two of the dams in the watershed: Yttri-Primer North, Yttri-Primer South, and Jersey Valley. The sites are lithic scatters (lithic scatter consists primarily of lithic flakes and other stone tool use remnants. Scatter occurs in surface areas that have often been disturbed by agricultural and natural events. Lithic scatters are used to study past inhabitants and are often the only evidence remaining) and areas were used to procure lithic raw materials. There is very low site integrity at two sites (Jersey Valley and Yttri-Primer South) and the sites are not eligible for the National Register of Historic Places (NRHP). No additional archaeological investigations are recommended at these sites.
“Based on good site integrity with the potential to encounter subsurface cultural deposits and density of cultural material at one archaeological site, Yttri-Primer North may be potentially eligible for listing in the NRHP. This site may provide information that will inform archaeologists about areas selected by past groups to collect lithic raw materials in the region. Additional Phase II evaluation is recommended at the site.”
“The report on the Yttri-Primmer North site details that ‘Twenty-three pieces of lithic debitage and one flake tool from five shovel tests probes that make up a moderate lithic scatter.’
“Of the twelve [architectural] properties surveyed in the APE for secondary effects, two are recommended eligible for the National Register. These are:
• The Anton Nelson Farmstead under Criterion A: History in the area of Ethnic Heritage for association with early settlement patternsamong immigrant communities and under Criterion C: Construction Technique as an example of a dovetail notched log cabincommonly adopted by Norwegian settlers.
• Bloomingdale School under Criterion A: History in the area of education as the sole school in 118 Cultural Resource Investigations for the West Fork Kickapoo Watershed in Vernon County Wisconsin the Village of Bloomingdale and under Criterion C: Architecture as an example of a mid-twentieth century, rural two-room school property type.”
Coon Creek
Phase I archaeological investigations were conducted at 14 dams within the Coon Creek Watershed that covered approximately 63acres. No cultural material was encountered at six of the dams within the watershed. No additional investigations are recommended at these dams.
Two previously recorded archaeological sites coincided with the survey APEs, Johnson at the Peterson Dam (CC24) and Letterly Two at the Luckasson Dam (CC21). Artifacts from the [Luckasson Dam] site were relocated with the recovery of lithic debitage and three projectile points dating to the Late Archiac and Early Woodland (3000 – 2000 BP). A single diagnostic, potential lancelot project point was recovered from the Blatz South site at dam CC25. The project point probably dates to Late Paleoindian and Early Archaic time periods, 9000 to 6000 years ago.
Based on good site integrity with the potential to encounter subsurface cultural deposits, the density of cultural material, and presence of diagnostic material, three archaeological sites at the Peterson, Luckasoon and Berg Coulee dams may be potentially eligible for listing in the NRHP. Additional Phase II evaluation is recommended at these three sites.
The Architectural History Summary yielded the following results:
“Of the nine properties surveyed…four are recommended eligible for the National Register. These are:
• Skogdalen Lutheran Church under Criterion C: Architecture as an Early Gothic Revival church constructed of quarried stone.
• Skogdalen Church Parish Hall under Criterion A: History either in the area of social history for its association with the temperancemovement in the region or in the area of education for its association with the rural school district in the region. Further research would be needed to confirm either association.
• Snowflake Ski and Golf Club under Criterion A: History in the area of recreation for its association with ski jumping in the state ofWisconsin.
• Edwin Sedevie Farmstead under Criterion C: Architecture as an intact collection of agricultural buildings that is representative of a typical farmstead in the Coon Creek Watershed and the broader Northern Tobacco District that engaged in both dairy production and tobacco cultivation.”
