Dam(s)

  • Bill Wahl: Flood Recovery and/or Flood Prevention

    The following is an  pdf open letter  addressed to the citizens of Alberta, from Bill Wahl of Medicine Hat. The letter expresses how Mr. Wahl has been affected by floods, but also points out how water in Alberta is being managed and areas for improvement. Have a read and please continue to share your thoughts with us through FacebookTwitter or Email. Thanks for sharing, Mr. Wahl!


    An open letter to the Citizens of Alberta

    Flood Recovery and/or Flood Prevention

     

    My name is Bill Wahl and I am frustrated!!

    Like others in Medicine Hat and Southern Alberta we live in proximity of the South Saskatchewan River [have for 40 years] and have been affected by flooding, all-be-it not this year due to the installation of a high tech backflow preventer after the 1995 flood. We are thankful to family and friends who helped us move out of our home and for better preparedness of disaster services.

    The main reason for my frustration is that I always thought that the dams on the tributaries of the South Saskatchewan River were there in part to help us out during times of impending floods. The Alberta Government meetings after the ’95 flood reported that flooding was caused by a severe precipitation event that occurred in very close proximity to the Oldman River Dam. That and a combination of technical issues caused by washed out flow sensors, telephone communications and the short time from onset of precipitation to significant increases in inflow did not give dam operators sufficient time to spill water ahead of high water entering the dam. Although dam safety was never an issue, water was released from the dam at a rate no greater then inflow.  So what happened this year?  According to records obtained from Alberta Environment and Sustainable Resource Development, the 2013 peak was ~5590 cm3/s and the 1995 peak was ~4200 cm3/s. The gauging station reports of the 2013 peak was more than 1m higher than 1995.  The cross section of the river valley at other locations will affect this value to some extent. Levels in Medicine Hat never reached those predicted with an increase of 50 cm3/s increase in flow rate over 1995 reported.  Persons who experienced the 1995 levels commented on water levels about 20 cm higher; all this being enough to cause significantly damage in Medicine Hat. How is it that the dam[s] that impact our flow rate could not have done more to mitigate flood issues this year given the knowledge gained from the ’95 flood, and  new technologies for weather forecasting? We have experienced more floods in the past 20 years than the first 20 years of living by the river.