With the assistance of Ayres Associates, the lake’s water
quality has been improved and the surrounding park space
has become safer, healthier, and more accessible to parkgoers.
“The improvements bring a natural sense of place;
they return Lake Minnehaha to an experience and a
destination,” said Chris Pletcher, Ayres’ project manager.
“We’ve restored the lake so that it’s now functional and
beneficial to the park today but also tied to the historic
roots of the City of Cheyenne.”
Report details poor conditions
In spring 2011, the City’s Parks and Recreation Department
hired Ayres to create a conceptual report to address
the lake’s ecological health issues. At the time, bluegreen algae, which thrives in shallow, non-circulating
environments, was taking over the lake, and dissolved
oxygen levels fluctuated from high to low during the
course of the day based on sunlight.
Mitigating
“It destabilizes the ecosystem and pushes out a lot of
beneficial species, so it’s not even healthy ecologically let
alone visually,” Pletcher explained. “While a lot of people
in town used the park, it was less and less attractive just
because of the smell and the poor water quality. The bluegreen algae can at times be toxic, and so there were also
questions of health hazard.”
Ayres’ conceptual report addressed the factors
contributing to the lake’s poor water quality, picked up on
previous water quality studies recommending that it be
filled in if the issues can’t be resolved, and mapped out a
proposed remediation plan.
“So the questions that the City asked us were ‘Is there
a way to fix it, do we know what’s going on here, or
are we just spending fruitless effort that won’t result in
improvements to the lake?’ ” Pletcher said.
Recommendations made
The remediation plan outlined a prioritized, two-phased
plan of correction. Phase 1 efforts included increasing
circulation in the lake, removing an island, and deepening
the lake from 3 to 8 feet, all of which would help control
the blue-green algae growth and keep the lake cleaner.
Removing the island not only helped with water circulation
but also eliminated what had become an unwelcomed
goose habitat – with additional problems resulting from
their droppings.
the
Remediation plan restores balanced
ecosystem to historic Wyoming lake
By Jennifer Schmidt
O
n any given day community members in Cheyenne, Wyoming, convene in and
around Holliday Park for a variety of recreational uses. Some bring picnic lunches,
others use the space to exercise, and most just simply enjoy the views of historic
Lake Minnehaha.
But it wasn’t long ago that the now peaceful, picturesque body of water looked more like
split pea soup – and smelled putrid.
“We had a lot of citizen complaints about the smell,” said Rick Parish, the City’s director of
Parks and Recreation. “It was just an eyesore located in the center of the City, which was a
real concern because it’s our second most popular park for usage.”
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