Tuesday, 28 October 2008

Lake of the Prairies – The New Lake Winnipeg?

New Report Expresses Water Quality Concerns - by Larry Powell

"Clean, potable drinking water is critical for human life and, therefore, a necessity for prosperous, sustainable communities." - Shell River State of the Watershed Report - 2008
A study of western Manitoba’s Shell River watershed points to the buildup of nutrients as the most serious water quality problem in the region.
The 2008 "State of the Watershed" report by the Lake of the Prairies Conservation District is a report card on the health of our surface and ground water.
Its verdict? It could be better!



Autumn in the Shell Valley - photos by L.P.
The Shell River rises in the Duck Mountains and meanders southward for almost 80 kilometers before emptying into the Lake of the Prairies at Asessippi Park.
The watershed stretches well into Saskatchewan. In Manitoba, it covers almost 3,000 km2, and includes parts of the Duck and Riding Mountain Parks, and the communities of Roblin, Inglis and San Clara.
The study by technical experts, says farming and other activities are adding excess sediments and nutrients to waterways in the region.
These nutrients cause harmful, sometimes toxic algae to grow, robbing those waterways of oxygen and killing fish in both summer and winter.
Mucky green messes caused by algal blooms are often seen in the Shellmouth Reservoir in late summer and early fall.
The report calls the buildup of these nutrients, especially phosphorous, the most critical water quality issue in the region.
But there are others.
People are channeling or trenching waterways to improve drainage.
This increases both the speed and volume of water in them.
Erosion of the banks and even more rapid movement of nutrients and sediment are the result.
The report’s authors express concern that human activity is damaging or destroying “riparian areas.” These are natural buffers like trees along the shorelines that protect waterways and provide wildlife habitat.
Governments have long encouraged farmers to preserve such riparian cover and keep livestock back from the edges. (Manitoba even offers tax breaks to farmers who do this.)

A common sight. (r. & below) Trees bulldozed around waterways - Livestock with easy access. Banks slumping. Cattle manure washing in, reducing water quality, not only for humans, but for the cattle themselves.









Photo (r.) courtesy the Upper Assiniboine River Conservation District.




Photo by l.p.
Despite programs such as the Riparian Tax Credit, the report estimates that at least 30 kilometers of riparian areas in the watershed are at risk of erosion. Streams flowing through cropland are of special concern.

Test Results Are Revealing

Tests for pesticides and bacteria show these to be mostly within provincial drinking water quality guidelines.
Silt and suspended solids were occasionally higher than the guidelines.
Levels of dissolved salts and minerals, like calcium and sodium, often exceeded objectives for irrigation. The report suggests both industrial and municipal discharges can adversely affect such levels.
Iron and manganese, which can give water an unpleasant taste and colour, were found to be consistently above recommended levels in both the Shell and Assiniboine Rivers.
But the most troublesome finding has to do with nitrogen and phosphorous, mostly the latter.
Phosphorous is a common nutrient in sewage and livestock waste. Once it gets into waterways, it promotes the growth of algae.
Tests show phosphorous levels in the Shell River watershed consistently violate Manitoba’s guidelines for drinking water quality.
Ironically, people are destroying natural features of the landscape that could improve the nutrient problem. The report finds that people are draining wetlands “without regard to negative ecological consequences.”
A study by Ducks Unlimited, quoted in the report, suggests up to 70% of wetlands in the watershed have been either lost or degraded since 1968.
Wetlands act as nutrient “sinks.” They filter out up to 90% of sediment, nutrients and bacteria from receiving waters.
They also allow water to percolate through soils, recharge groundwater supplies and buffer the impact of both floods and droughts, by capturing water and releasing it slowly.
Yet drainage and infilling continue to damage these wetlands.

Groundwater Also Vulnerable

But surface waters aren’t the only concern in the report.
Bacteria that indicate the possibility of contamination from the surface are commonly found in private water wells.
The serious kind, E.coli, was found in 6% of water samples taken. E.coli can be found in human and animal feces.
The study warns that water from almost all of the public drinking water sources within the watershed, while safe to drink, are at “high or moderate” risk of pollution.
Places falling into this category include Inglis, Asessippi Park and East Blue Lake in Duck Mountain Park.
The appearance of some public groundwater sources is also being affected.
For example, the public water supplies of Ricker's Campground on Lake of the Prairies, as well as the Towns of Roblin and Inglis, exceed the Guidelines for Canadian Drinking Water Aesthetics for factors such as manganese, hardness, and Total Dissolved Solids (TDS).

Wildlife

The report goes on to say, several species of birds, fish and plants face an uncertain future in this area. That’s because their habitat is being lost more quickly than it is being restored.

Spragues’ Pipit (l.)is one of the species in the Shell River Watershed at risk. (Photo courtesy GoogleImages.)


Recommendations


The report calls for several steps to be taken to improve the situation. Among them;
• No more net loss of sloughs, wetlands or potholes.
• Neglected, abandoned or unused wells should be sealed because they can act as a direct pathway for contaminants from the surface.
• New drainage projects should be done using Best Management Practices, with careful regard for the environment,.
• Solve the lack of long-term planning by creating a watershed-wide Surface Water Management Plan.
The Conservation District will hold public meetings on the report in Roblin and Inglis next week.