What are the problems with our lake?
Lac Gauvreau was one of the earlier lakes to become populated due to its size and closeness to Ottawa and Gatineau.
In the early years there were no real septic systems, and as more cottages were built, the lack of proper septic systems contributed to deteriorating water quality. Cattle along the stream shoreline further polluted the lake with nutrients and fecal coliforms. In fact, at certain points, it wasn’t safe to swim in the lake because of all the sewage that had been dumped there.
Between 1962 and 1964, Ruisseau Parent—a meandering creek with a watershed of about 45 km2 that feeds Lac Gauvreau—was straightened, as it would increase productivity for the farmers along Parent Creek. This was disastrous for the lake, as many more sediments and nutrients were deposited in the lake. Most of the nutrients would sink to the bottom and bind with the small sediment particles so that, after 60 years, the lake is now on the edge of being Eutrophic, causing algae blooms, including some blue-green algae (Cyanobacterium), which can be dangerous, especially for pets and small children. (Article continues below image.)
The old creek bed of Parent Creek, in blue, based on an aerial photo from 1945 layered on top of Google Earth imagery with the current bed. Just visible (right bottom) is the mouth of the creek in ac Gauvreau.
Motorboats became more powerful and would disturb the sediments at the bottom in the shallower parts of the lake, also contributing to a higher nutrient load in the water. Those higher nutrient loads would eventually cause the blue-green algae blooms that we now see almost every year.
About 10 to 12 years ago, Eurasian watermilfoil started to appear in the lake. This plant with the nickname “Zombie weed” is an invasive species, likely brought in by boats. As it is also an aquarium plant, perhaps somebody emptied their aquarium in the lake. It spreads very easy as broken pieces, even small fragments cut up by boat propellors, will float in the lake and eventually become a new plant. At this time most areas where the plant can grow have already been infested.
Numerous measures have been taken to try to improve the water quality in the lake and Parent Creek. Farmers have put fencing along the creek, with mixed results. The municipality has done a septic system inspection blitz around the lake, and several septic systems have been replaced. Owners around the lake have started improving their shoreline to filter nutrients from runoff water, and nobody around the lake uses fertilizers anymore.
Since 2022, new boating guidelines should help reduce wake and the proliferation of milfoil, and hopefully also reduce the amount of nutrients that can be released from the shallower parts of the lake. Although fecal nutrient counts have decreased significantly—making it in that aspect good swimming water—the nutrient loads have not decreased and are now causing the blue-green algae blooms making the water potentially dangerous to swim in.
Despite all the measures to reduce nutrients in the lake, the nutrient levels remain largely unchanged. They have not worsened, but they are also not improving. Therefore, we need continued vigilance, and we must continue to step up and work on all fronts to make our lake healthy again.
For more information about problems, read the following reports
- Characterize the aquatic habitats of Parent and Gibson Creeks (18 Km),
- Characterize the conditions of the creeks shorelines and erosive areas,
- Establish a five-year plan for the revitalization of aquatic ecosystems.
The dredging of the Parent creek in the 1960s resulted in the disappearance of habitat diversity. The Association thought that it was possible to implement corrective measures to revitalize the creek, increasing the quality of fish habitats and their productivity. The aquatic habitats of the creek were not known at the time. Acquiring this knowledge was an essential first step in establishing priorities for its revitalization.
The following were the specific objectives of the project:
The GLEPA mandated a private consultant’s firm to conduct the characterization of the Parent creek. Read more and see the report below.
Due to a GLEPA initiative, the environmental consulting firm PRO FAUNE published a ‘Development Plan for the Aquatic Habitats and the Banks of Parent Creek’. This study report identified a number of concerns that affect the quality of the aquatic habitats of the creek – and as a consequence, the water quality of Lac Gauvreau – including the condition of the creek banks along the farm fields, the electric fencing, and the access by cattle for drinking water.
Information already available was combined with data collected on the ground in September 2007, allowing an evaluation of the problems of Parent Creek and the formulation of recommendations for the development of the potential for fauna and of water quality. With this information, the Association and its local and governmental partners were able to compose a plan for intervention and protection of the sensitive habitats for fauna and the creek banks in order to preserve the biodiversity of the principal inflow to Lac Gauvreau.
In summary, to improve the quality of the Parent Creek ecosystem and to optimize its potential for fauna, the report deemed it essential to keep livestock at a distance from the Creek, to establish adequate watering sites, to stabilize the creek bed and banks, and to ensure the effectiveness of individual septic systems of residences in the drainage basin in order to reduce the runoff of suspended material, total phosphorus and fecal coliform.
> Read the Parent Creek revitalization study; key findings published June 28, 2008
> Read the full report: 2008 Bolduc Ruisseau Parent
> Read the Executive Summary Parent Report
> Read article in Gauvreau Lake News, June, 2008
BACKGROUND TO WHY THE 2008 REPORT WAS PRODUCED
In 2007, Lac Gauvreau received $14,000 to study the impact of pollutants flowing into Lac Gauvreau from Parent Creek. According to The Low Down to Hull and Back News August 29 - September 4, 2007, “…The aim of the study… is to… pinpoint the sources of any deterioration [of Parent Creek], such as high levels of nutrients. High levels of nutrients, like phosphates, can lead to higher chances of algae bloom…” [and of promoting the growth of Eurasian water-milfoil].
> Read Association press release