Low water levels in Lacombe Lake threaten to boost algae growth and endanger fish, said a group dedicated to protecting the lake.
Cliff Soper, of the Lacombe Lake Watershed Stewardship Society, said lake levels have been dropping in recent years and there are concerns lake quality will be affected.
The lake, three kilometres long and 500 metres wide between Blackfalds and Lacombe is only three metres deep at its deepest point. As it grows more shallow natural nutrients become more concentrated and sunlight can penetrate further, causing more plant growth. As those plants and weeds decay they use up oxygen needed by fish.
Last winter, volunteers found a number of fish dead because of low oxygen levels.
The society wants Lacombe County to adjust a gate in a weir at the north end of the lake to allow more water to flow in from Whelp Creek, or Whelp Brook as it is sometimes called. The county oversees operation of the weir through a licence with Alberta Environment and Protected Areas.
Soper said the society has worked with Alberta Lakes Management Society to monitor the lake, including collecting data on its depth, temperature, turbidity, oxygen levels, plant growth and presence of invasive species.
“We are confident that the data we have collected strongly requires that some changes be made to maintain the water quality, a healthy and varied wildlife at the lake and to provide an enjoyable experience to the ever-increasing number of canoeists and kayakers who are coming to the lake,” says Soper in a letter he wrote to Lacombe County.
Recent dry and hot summers have led to an increase in evaporation and contributed to lake quality problems.
Soper said there is nothing that can be done about the weather. “The only thing we can control is the weir.”
He asked that the county agree to allow the maximum amount of water allowed under the provincial licence to flow into the lake.
County council asked administration to prepare a report on options and bring it back to a future council meeting.