Important information on high water across MCWD

Monday, August 18, 2014

The wettest Twin Cities spring on record caused historically high water levels on lakes and streams across the Minnehaha Creek Watershed District. Lake Minnetonka reached an all-time high of 931.11 feet above sea level on Monday, June 23 and spent 45 consecutive days above the pre-2014 all-time high of 930.52. Now that levels have begun to recede, the District is assisting its communities in flooding recovery and helping understand what to do next. 

2014 Minnehaha Creek Cleanup: The 2014 Minnehaha Creek Cleanup was been re-scheduled for Sunday, September 7 due to the high water, and there should be plenty of trash to pick up! RSVP today!

Wake Restrictions on Lake Minnetonka: The Lake Minnetonka Conservation District (LMCD) lifted its High Water Declaration on August 4, ending the minimum wake restrictions on Lake Minnetonka. High water levels continue to remain a concern and it is so important that all watercraft operators understand the regulations of their wake, as well as the standard speed limits that apply. Learn more here.

Flood recovery

Many residents of the MCWD were impacted by the high water and flooding. Below are some resources for flooding recovery:

  • Damaged shoreline?
  • Trees and flooding: The University of Minnesota Extension has information about the impacts of flooding on trees
  • Disposing of sandbags: From the Minnesota Pollution Control Agency: "Floodwater can contaminate sandbags with bacteria and other pathogens. And used sandbags that are not properly managed can develop mold over time." Read the MPCA's list of tips for disposing of sandbags after a flood.
  • Disposing of AIS that washes ashore: The high water means more debris washing up on shore, which for some lakes and streams will include aquatic invasive species like zebra mussels or Eurasian watermilfoil. Please be careful in disposing of these harmful plants and animals to make sure you don't spread them elsewhere. Options for disposal:
    • Compost. The heat generated by the composting process kills zebra mussels and will break down milfoil and other aquatic plants
    • Take to a yard waste facility. Transporting AIS requires a permit from the Minnesota Department of Natural Resources. You can apply online.
    • Toss in the trash. Contact your garbage hauler and ask if they are permitted to transport aquatic invasive species in Minnesota
  • 2014 Minnehaha Creek Cleanup: The 2014 Minnehaha Creek Cleanup has been re-scheduled for Sunday, September 7 due to the high water, and there should be plenty of trash to pick up! RSVP today!
  • Assessing damage: 
    • The Minnesota Department of Employment and Economic Development is conducting a survey on flooding impacts to businesses. Learn more and fill out the survey online.
    • MCWD is assessing damage across the District and plans to work with communities on repairs and mitigation efforts to prevent damage from future high water events.

2014 Dam Operations

Due to the record rainfall this spring and early summer, the volume of water in the system exceeded the Gray’s Bay Dam’s capacity to manage water levels on Lake Minnetonka and Minnehaha Creek for more than two months. Water started going over the spillway north of dam when lake level went above 930 feet on May 9.  

Prior to ice out this year, the District assessed the lake level and determined there was sufficient capacity in the lake for the spring snow melt. After ice out, the lake level was approximately ½ foot below the top of the spillway and the dam was opened according to the DNR-approved operating plan.

Soon afterward a wet weather pattern ensued and staff increased the dam discharge rate to mitigate rising lake levels , in accordance with the operating plan. However, continued bouts of heavy rain throughout the months of May and June caused lake levels to continue to rise, exceeding the dam’s capacity to manage water levels, resulting in flooding on both the lake and creek. Learn more about the Gray's Bay Dam Operating plan here.

   
(Before and after: The emergency weir north of the Gray's Bay dam, from May 1 and June 20)

Beach closures

Hennepin County provides an updated map of the status of public swimming beaches.

Flood Risk Profile and Flood Insurance

The following resources provide information on assessing your flood risk and obtaining flood insurance:

Be safe around high water

In a car: Do not try to drive through a flooded roadway. As little as 2 feet of flowing water can carry away most vehicles, including SUVs and pickup trucks. Do not attempt to drive through water that comes close to halfway up your wheels, turn back. Rather, reverse carefully out of the water. Keep in mind that 80 percent of flood deaths occur when people try to drive through and become submerged.

On foot: Do not walk in or play in flooded streets. It only takes about 6 inches to knock an adult off his or her feet, and less for a child. Mucky water also can obscure sharp or other dangerous objects or sinkholes that could cause injury.

Flood water is not clean water: Flood water often contains sewage and other pollutants that can cause illness. Flooded buildings also can quickly become unhealthy places, due to contamination and mold and mildew, which can grow very rapidly. 

Read more tips from the Minnesota Department of Health.