Study about flood control dams starts local operations
LaCrosse, Vernon and Monroe counties in southwest Wisconsin are home to a quarter of the large (PL-566) flood control dams in the State of Wisconsin. Built mostly in the 1960s, the dams are now aging infrastructure in need of repair, replacement, relocation or removal.
The study being undertaken by USDA-NRCS and the three counties will help to determine the future of the five dams that breached in the August 2018 rain event. It will also lend insight into all the other similar dams in those counties which share certain structural and age-related challenges, although they are not breached.
“The dams in this area are 60-years-old, and the federal interest in them has been completed (meaning they’ve exceeded the project life used in the original economic evaluation),” USDA-NRCS Wisconsin State Conservation Engineer Steve Becker told a group of county and town officials, agency staff and representatives of the engineering firms contracted to complete the study. The group gathered in the Cashton Community Hall on Tuesday, August 4 for a project kick-off meeting.
“The dam failures resulted from 11 inches of rain in about six hours on August 27-28, 2018, and a vulnerability in the highly jointed sandstone abutments on each end of the dams,” Becker told the group. “There are similar vulnerabilities in the dams that did not breach in 2018, as well as normal aging of materials used in construction of the dams."
The study will be focused on the Coon Creek and Upper West Fork Kickapoo Watersheds, where the five dams breached. According to Becker, “the purpose of this study is flood prevention and flood damage reduction.”
Becker explained that the funding for this project became available because there is bipartisan recognition that U.S. public infrastructure needs an infusion – this resulted in the 2019 Consolidated Appropriations Act, as a source of funding for this watershed planning effort.
The planning effort will result in a Project Plan for each watershed, as well as an Environmental Impact Statement – which are intended to help decision-makers weigh the environmental, economic, and social impacts or consequences of the Project Plan. The planning effort is estimated to be complete on December 31, 2021.
Historically, when the dams were first built, similar studies were undertaken in the two watersheds. Those studies resulted in project plans, and ultimately in construction of the dams. The project will soon have a website up, and interested citizens can view the original project plans at that site. To find the website go to www.wfkandccwatershed.com. The site is currently still in development, but should be available soon.
Public scoping meetings
One of the key things called for in the study is to obtain citizen input on the problems with flooding, and eventually, on the proposed solutions put forth. This will be part of the process of developing an Environmental Impact Statement (EIS) for the project. There will be two sets of public scoping meetings in each watershed.
“The first scoping meetings will be in September to identify problems, concerns, and potential alternatives to address valley flooding,” Sundance-EA Senior Project Manager Keri Hill told the group, “The second meeting will be in December or January to review the preliminary results of floodplain modeling and the environmental and economic impacts. The meeting will also focus future efforts on certain alternatives.”
Wisconsin 96th Assembly Representative Loren Oldenburg attended the meeting. He suggested that “before you have the meetings, you should make a list of questions to prompt for ideas and concerns, so you are sure to come out of the meetings with the information you need.”
Those meetings will take place at the Cashton Community Hall for the Upper West Fork Kickapoo Watershed, and at the Coon Valley Village Hall for the Coon Creek Watershed. Due to COVID-19, and the need to maintain social distancing, in-person attendance will be limited, but a live virtual meeting will also be available to those unable to secure a seat for the live meeting.
The Coon Creek Watershed meetings in Coon Valley will take place on Wednesday, Sept. 16 – one from 10-11:30 a.m., and one from 6:30-8 p.m. The location of those meetings will be announced soon.
The Upper West Fork Kickapoo Watershed meetings at the Cashton Community Hall will take place on Thursday, Sept. 17 – one from 10-11:30 a.m., and one from 6:30-8 p.m.
Because in-person attendance will be limited, it is encouraged that only one member from a family attend the in-person meetings. Seats at the meetings will be available first come, first serve. The link and instructions to use the free live streaming platform of Microsoft Teams will be available on the project website, and distributed through the three county Facebook pages.
For the study, USDA-NRCS has contracted with M&E Consultants. They have also sub-contracted with Sundance Consulting and EA Engineering Science and Technology, Forest Econ, Inc., and Cornerstone Restoration.
M&E Consultants was formed by two retired NRCS State Conservation Engineers in Texas in 2001. M&E currently employees 40 retired federal employees with more than 1,000 years of experience when employed by the Natural Resources Conservation Service (NRCS), formally the Soil Conservation Service (SCS). Their experience is in planning, design, construction oversight, conservation practices, program administration, and engineering management. During the past 29 years, M&E Consultants LLC has provided planning, design, survey, geotechnical, and/or construction inspection services on 315 project dams located within the U.S. Central Region.
Steve Becker addressed the question, “why are we contracting with an engineering firm from outside of Wisconsin?”
“USDA-NRCS has a high level of confidence this team will be able to handle all aspects of the project,” Becker explained. “With this team, when we send the final report off to Washington D.C., the report will have the technical evaluations and administrative format to qualify the selected alternatives for the next phase of federal funding.”
In addition, M&E Consultants has sub-contracted for some of the study work with two other firms.
The Sundance-EA Partners, LLC, Joint Venture, is a Native American-Woman Owned Small Business (WOSB) that brings together Sundance Consulting, Inc., (Sundance) and EA Engineering, Science, and Technology, Inc., as a full-service consulting firm to provide environmental, compliance, natural resources, cultural resources, and remediation services to clients across the United States and abroad. Together, Sundance and EA employ more than 500 professionals and maintain a network of 30 offices nationwide.
Forest Econ, Inc., is an independent forest and natural resources economics analysis firm located in Moscow, Idaho. One of their two project groups that will work on this study is the natural resources economics team. This team provides resource valuation, project cost-benefit analysis, investments, forecasting, and management.
Cornerstone Restoration specializes in infrastructure restoration. Their team will crawl through the principal spillway pipes of the dams to evaluate the competency of the pipe joints and concrete surfaces.
EA-Partner’s Robb Lutz and team will lead the floodplain modeling, and will estimate the remaining life expectancy of the structures. In the course of doing this, they will conduct interviews with impacted landowners in the valleys to correlate economic damages with various flood stages, and discern their interest in land use changes, easements, and zoning.
“Our study will identify the differences in the flood inundation area with each scenario – repair, replace, relocate or remove, EA-Engineering’s Robb Lutz told the meeting participants. “It will provide the benefit-cost analysis for each scenario.”
Lutz said his team is looking at conducting landowner interviews tentatively in October. He said that those interviews will establish economic damages from flooding, level of interest in land use changes, and hydrologic information about high water marks, etc.
Vernon County Conservationist Ben Wojahn expressed concern that the study discuss not just the dams but also the land use in the watersheds above them that allows them to function.
“Historically, I’ve heard that landowners were paid to install conservation land use practices – if we do this again, it needs to include a deed restriction so the practices can’t be removed by the next generation,” La Crosse County Town of Washington Board Chairman Dan Korn said. “It’s all just corn and bean fields now on the ridge top fields.”
Korn said that without the dam in the Bohemian Valley tributary of Coon Creek, residents have noticed that the water draining off from rain events is more violent.
Tim Hundt from Congresssman Ron Kind’s office noted that the original watershed plans required that 50 percent of the landowners in the watershed signed cooperative agreements to install conservation land use measures.
“In the study, we will look at upper watershed land use for the last five years – we will look at crop rotations and investigate the impact of those rotations on flooding outcomes,” Becker said. “As far as evaluating new rainfall trends, we will use Atlas 14 data for the general scope of modeling. From the project funds, we also devoted $10,000 for a UW-Madison study that captured and quantified rainfall trends in the last 15 years. This trend of more frequent and intense rainfall will be applied in the economic evaluations of valley flooding.”
Becker pointed out that the focus areas in the Coon Creek and West Fork Kickapoo Watersheds are large - 68,762 acres and 63,761 acres, respectively. He said that in the early part of the planning effort, they will not be able to evaluate detailed land use changes within the upper watershed.
“We could make some gross estimations, for instance, we could add grass buffers around the perimeter of all of the ravines in the watershed, calculate the acres of grass, plug that into the model, and see if installing that would move the needle with regard to flooding– we could also evaluate substantial land use changes on all areas of highly erodible land.”
He said that in the later part of the planning effort, they will be able to look at the effect of detailed land use changes and conservation practices in smaller sub-watersheds that contribute runoff and sediment to individual dams, such as farm ponds, terraces, grassed waterways, cover crops, or specific rotations.
As part of Cornerstone Restoration’s evaluation of the principal spillway pipes on the dams, county staff will need to address spring baseflow that feeds water into the system on a perennial basis to allow their staff safe access.
“Inspections of the principal spillway pipe and drains will help the planning team estimate the remaining life of the 23 dams in the two watersheds, and anticipate the cost of any needed repairs,” Becker said. “Replacement of the principal spillway pipe is synonymous with the expiration of the dam. The excavation and material costs required to replace the pipe often exceed the value of the dam.”
Becker explained that the study will also investigate hydraulic capacity of the 68 road crossings in both watersheds, split about 50/50 between the two. This will include roads and bridges, and the study team will require county records about damages, maintenance and repairs.
Another key aspect of the study will be a detailed evaluation of the benefit-cost ratio of the dams. When the project plans for the dams were originally made, the benefits and costs of having them in place involved a lot of estimation.
“Now, 60 years later, we have the benefit of being able to look back and to see what those benefits and costs actually were,” Becker said. “Originally, it was estimated that the benefit cost ratio of building the dams would be 1.2:1 – now we’ll be able to test those estimations and use the results of the economic analysis to refine our recommendations going forward.”
Becker said that USDA-NRCS, U.S. Army Corps of Engineers, Wisconsin DNR, and the U.S. Fish & Wildlife Service all have regulatory interests in the dams. In order to perform our economic analysis, we will need cooperation from all these agencies, as well as the three counties.
“We will need dam operation and maintenance costs from the three counties since 1958 – this information will need to come from NRCS, DNR and the counties,” Becker said. “We’ll need numbers for average yearly maintenance and operation, and for major repairs, and this can include annual staff salaries and dedicated equipment.”
Becker said that the economic analysis team will also want zoning information and property value information to be able to calculate the impact on property values if dams are constructed or abandoned, and the value of property rights lost due to floodplain and hydraulic shadow zoning as those rights have a value.