January 2017 East-End Rock Dam Washout

East-End Rock Dam Washout

Once again, the fragile east end of our rock dam has washed out.  While we cannot measure the lake elevation when the lake is frozen over, the water level under the ice is undoubtedly lower than normal.  The most recent prior occurrence of this type of failure was in April, 2013.  The lower water level caused the lake ice to bow downward at the shorelines and the DNR posted the lake as unsafe for recreational activities.  Please be extra cautious if you have any need to be out on the lake ice the rest of this winter.

 

Clearly, there is a heightened sense of urgency regarding the timing of the new structure’s installation (which will be a critical factor in determining if or when the rock dam will be repaired).  While steady progress has been made in getting the CPL Grant contract in place, securing the necessary permits and documenting agreements among all the project partners, we are not yet at the point of scheduling construction.  In fact, considerable time and energy will soon go into preparing a contractor bid package, soliciting bidders, evaluating bids and selecting a winner.  If all bids exceed available grant and matching fund levels, the project may need to be staged and/or additional funding secured.

The BPLA Board feels we should not initiate immediate repairs of the latest breach for several reasons:

  1. The spring thaw will soon generate large volumes of snow and ice melt that will result in high outflows from the USACE dam in Crosslake (which was the cause of the 2013 east end failure) so it would be risky to repair it before then and impossible to repair it during high water.
  2. With the steady progress of the Pine River Fish Passage project, the old rock dam will soon be replaced by a new arched riffle structure so the Board feels it would be short-sighted to spend any SSD maintenance funds on a temporary repair. Those funds are much better used for preventative maintenance by replacing the fragile rock dam with a more durable structure.
  3. The recent breach creates both a natural diversion channel on the east end and unusually low lake elevations which may actually facilitate the construction of the new arched riffle structure.

A Memorandum of Understanding (MOU) has been drafted to clearly state the responsibilities of all project partners and is currently in the legal review process.  BPLA’s responsibilities and commitments are included in this document along with those of the Soil and Water Conservation District (SWCD) and Crow Wing County (CWC).  Soon after the MOU is approved and signed by all parties, it will be presented to the CWC County Commissioners along with a comprehensive project briefing.  The current target date for that meeting is February 14.

 

Although CWC will continue to own the new replacement structure, SWCD has graciously offered to manage the entire bidding and construction process.  The associated responsibilities and agreements of that arrangement are included in the MOU and other contractual documents.  Funds from the Big Pine Lake Subordinate Services District (SSD) accumulated account balances will be used to satisfy the non-state matching funds requirement of the CPL grant.  Big Pine Lake property owners will continue to financially assist CWC with maintenance of the new structure through future SSD collections.


 Actual construction will be subject to weather as it relates to lake levels and flow volumes at the construction site.  Typically, lake levels and river volumes are lower from mid-July through August, although last summer was an exception.  As soon as a contractor is selected and a construction contract awarded, we can begin to target a construction period.  Since huge volumes of rock and other materials will need to be trucked in for this project, much of that can be done in advance while waiting for acceptable construction conditions.


 We will keep you informed of the status and key milestones of the project with periodic email updates.