Erosion Study Does Not Justify Lowering Lake
Our first entry for the newly created Editorial Page was originally written for the DLWID board of directors and presented to them for their April meeting. All indications are that the board may vote to lower the currently authorized summer time lake level from 9.53 feet to a yet to be specified height.
During his presentation, Paul Robertson indicated the District was limited to 18 inches of control over the lake level. That is the height of the summer time impoundment structure. The board delayed placement of the dam until after the May 10th meeting where a final decision will be made. We have reviewed the final Erosion Study and shared the following observations. Please take the time to get familiar with the document and make your opinion known.
Comments on Erosion Study
The recently re-released erosion study dated March 8, 2012 (version 2) was an interesting read but much like its predecessor (version 1), it provides little information that would compel the District to take action. This is due to thestructure of the RFP, which only requested advice on one topic; specifically it requests, “from this overall erosion study the contractor will provide a summary of the data and conclusions drawn as to if and how the dam operation may be impacting the shoreline.” The document did not request that erosion identified by the study be quantified nor did it request the study supply suggestions or techniques that could be employed to prevent or mitigate erosion on Devils Lake.
The erosion study RFP had a very narrow focus. Given its single-mindedness, did the erosion study deliver an answer? The original study (version 1) made a real attempt as it concludes, “whether waves are generated by boats or wind, the highly erodible nature of the soils, the presence or absence of sufficient bank stabilization, and the bathymetric slope are likely more influential on shoreline conditions than relatively small changes in lake elevations.” The new study (version 2), after three months of input from the District fails to reach a specific conclusion. The report instead suggests more study is necessary, “Due to variability in factors that affect wave energy that impact the shoreline, the vertical zone over which that energy is focused, and the ability of the resulting waves to cause erosion, local quantification of this process can only be done through site specific analyses. This analysis should consider the specific nearshore bathymetry of the lake, the alignment of the shoreline with respect to the predominant wind direction and angle of impact of boat waves, as well as topography, soils, vegetation, and the presence of man-made structures at and above the shoreline.”
A careful reading of the re-released erosion study (version 2) reveals many fascinating additions from the original study; these embellishments do not appear to contribute to the study’s ability to draw a conclusion or make a specific recommendation related to lake level. Indeed, the revised erosion study contains 117 references to the term “level” in describing the height of Devils Lake. Six of those references are found in the summary, which is now titled “Recommendations and Considerations”. This is the section that should answer the question “if and how the dam operation may be impacting the shoreline”1. It does not. The section contains no statement confirming or denying the impact lake level has on overall shoreline erosion. It does not contain a specific recommendation for an ideal lake level, nor does it recommend lowering the lake level.
The original study (version 1) committed to a thesis stating that other factors in the lake environment were more influential on shoreline erosion than small changes in lake levels. This is a conclusion that the District has rejected. The re-released erosion study (version 2) goes out of its way to avoid drawing any conclusion whatsoever. I would caution the DLWID board away from reading between the lines and drawing a conclusion where three professional scientists, engaged by the District have refused.
I have many other concerns related to the contents of the re-released erosion study (version 2) but it is my understanding from the staff report that a change in the authorized impoundment height is not being considered at this meeting. I will therefore withhold any further written comments until the District schedules a public hearing. As with the original study (version 1), I believe that the findings of the re-released erosion study (version 2) very clearly demonstrate that those public hearings will not be necessary.
Comments on Proposed Board Actions
The Staff Report associated with the April meeting suggests that the board needs to take action on two items related to the erosion study.
- Decision on the completeness of the contract and payment of the contractor.
Staff believes that the contract can be ruled complete and thus full payment should be issued to Tetra Tech, Inc. While the re-released erosion study (version 2) misses the mark absent a conclusion; I recognize that there were other deliverables subsequently forwarded to the District associated with the original contract that satisfy the majority of the RFP requirements.
I would agree that Tetra Tech should be paid and outstanding issues if any should be addressed by standard business decorum.
- Direction on the installation of the dam prior to the May discussion.
Staff has recommended delaying the installation of the dam structure, normally placed on April 15th until after receiving public comment at the May 10th board meeting. The staff report states that the board would then “make a decision about the use of the dam this summer and thus its installation.” It is unclear in this statement if the height of the impoundment structure is to be considered or the use of an impoundment structure is to be considered in the May meeting.
I recommend that the District install the dam on the traditional timeline, on or near April 15th. Unless the District is seriously considering managing the summer recreational lake level without an impoundment structure it makes no sense to delay construction. Should the District make the unfortunate decision to reduce the lake water level from the currently authorized 9.53′ MSL it can be easily adjusted with the structure in place as it is routinely done each summer.
 DLWID RFP: Erosion Study – Page 4
 Devils Lake Shoreline Erosion Study (Version 1) Nov 18, 2011 – Page 2
 Devils Lake Shoreline Erosion Study (Version 2) Mar 08, 2012 – Page 2
 DLWID Staff Report April 5, 2012 – Page 5