Mapping the Sylvan Lake Watershed

The SLWSS mission is simple: Protect the water quality of Sylvan Lake. To do so, it helps if we know what we are talking about. Due diligence for sound decision-making requires knowing lots of stuff.

And there is plenty to know about as publicly available data confirm.

Satellite and aerial images of the lake and the surrounding land are helpful to show the agricultural and urban environments that affect the state of the watershed.

Sylvan Lake Watershed Boundary.v2

Click to enlarge

The two major tributary catchments for Golf Course Creek and Northwest Creek are easily seen at high resolution. The boundary of the watershed is shown as a white line. The significance of that perimeter is that precipitation falling inside the line will potentially flow into the lake because of the contour of the terrain, carrying dissolved and suspended minerals, nutrients and contaminants with it. Note that the eastern section of the Town of Sylvan Lake lies outside the watershed boundary. Much of the stormwater, and all of the waste water, that is collected by the Town is diverted eastwards and out of the watershed.

Geographic Information System (GIS) software can consolidate and display layers of large sets of data as maps. The map below is a  multi-layer GIS graphic that contains several categories of data including the topography, roads, the Alberta township grid, two railway berms (that interfere with Golf Course Creek catchment flow and create a series of wetlands in the gully between the two), pipeline networks, plus the many regional tributary flows that are highlighted boldly in blue.

Watershed Master Map.v2

Click to enlarge

Protecting the lake and watershed starts with knowing the facts. The SLWSS, and the watershed municipalities, have the knowledge about land use and the surface and groundwater sources to do so.


Keep Nutrients on the Land……..Not in the Lake

Alberta Agriculture and Forestry (AB Ag) research on nutrient transport has evolved over two decades is relevant to the situation in the Sylvan Lake watershed. About 67% of the land area within the watershed boundary is used for agriculture. Those uses are also diffuse sources of nitrogen (N) and phosphorus (P) nutrients as a result of the cycle of growth and decay of organic material on the land. During the growth phase plants extract needed elements from the soil, particularly from the inter-granular water in the root zone that contains soluble building-block species of N and P. Plant decay, promoted by organisms in the soil, is continuous and releases cell nutrients back to the soil inventory for re-use. Farmers know that and use soil test chemical analyses to determine how much fertilizer must be added to grow the next crop, without adding an excess. Growing and harvesting food crops also mines the soil and removes nutrients that must be replaced to maintain crop yields.

P in Cell Walls

Phosphorus is an important element in phospholipids that form cell walls that can decay and disperse.

P in DNA

Cell DNA contains phosphate groups that can also be recycled into the environment.

AB Ag has found that the concentration of nutrients in the top few centimetres of soil is also an important source of available N and P in runoff into streams and water bodies. So is manure that is stored for use or dispersed on the land as nutrient-rich fertilizer. Typically, nutrient levels are the highest in spring runoff, then drop as the ground warms up and plants grow, trap, and retain N and P. The next graph shows SLWSS results from water quality sampling of Golf Course Creek in 2014 that confirm the AB Ag finding. Data from other Sylvan Lake tributaries follow the same pattern. The lowest N and P concentrations in those streams have always been above those measured in Sylvan Lake and summarized by ALMS in Lakewatch reports. So the natural nutrient cycle on agricultural and forested watershed land loads the lake with nutrients on an annual cycle.

N and P in GCC

SLWSS water quality sampling results for Golf Course Creek in 2014. High levels of N and P were found in Spring runoff. Nutrient concentrations through the summer remained above those observed in the lake itself.

The element phosphorus is often the critical limiting factor that controls the trophic state of lakes. Sylvan Lake’s long term average Total Phosphorus analysis of 21 micrograms per litre keeps the lake in a meso-eutrophic state with typically low chlorophyll-a concentrations associated with suspended plant matter. Algal blooms have been rare. The watershed community counts on it staying that way. That is why AB Ag’s application of field research findings and modeling studies into practical best management practices are important. Phosphorus is better fertilizing plants on watershed land than algae and plants growing in Sylvan Lake.

Instead of presenting a technical review of the excellent experimental and modeling nutrient transport work of AB Ag, the department’s publications can speak for themselves. Here is an introduction to a few that illustrate the scope and caliber of that research. Reports on three field studies:

are complemented by a fact sheet, a link to the very important Soil Phosphorus Limits Project web page, and a Phosphorus Sources and Sinks analysis:

The latest AB Ag approach to analyzing nutrient transport in Alberta watersheds will soon be available in a series of reports that will be posted on an Alberta Agriculture and Forestry publications web page. This post will be updated when those documents are approved for release.

An important Sylvan Lake watershed question, not yet answered, is about the magnitude of annual N and P nutrient loading of the lake from the surrounding agricultural land. The AB Ag work provides the basis for addressing that lake nutrient loading issue. Attempts to estimate the phosphorus and nitrogen loads by measuring tributary water quality and cumulative flow have yielded unsatisfactory results. Consequently, knowledge of nutrient transport processes in the Sylvan Lake watershed are inadequate to allow due diligence predictions of the impact of urbanization on the scale imagined in municipal plans.

The Alberta Geological Survey Takes the Groundwater Lead with the Sylvan Lake Project

The Alberta Geological Survey (AGS), now a part of the Alberta Energy Regulator (AER), is the Sylvan Lake watershed’s newest best groundwater friend.

We know that groundwater is important because everyone in the Sylvan Lake watershed extracts and uses well water. That underground supply of water is also critical for the rest of Alberta as the report “Groundwater in Alberta – An Assessment of Source, Use, and Change” explains.

The full scope of the Sylvan Lake project was introduced at the Watertech 2014 conference by Dan Palombi in the AGS-AER presentation “Integrating Numerical Modelling into the Groundwater Policy Assurance Process”.

The AGS groundwater team has built upon the major Edmonton-Calgary Corridor groundwater study and zeroed in on the Sylvan Lake-Gull Lake-Red Deer region. Phase 1 of the “Sylvan Lake” project investigated the geology under about 600 square kilometres of land that includes Sylvan and Gull Lakes and some of the Red Deer River valley. Those results are published in the AGS report “Three-Dimensional Hydrostratigraphic Modelling of the Sylvan Lake Sub-Basin in the Edmonton-Calgary Corridor, Central Alberta”.

Phase 2 takes the detailed geological data from Phase 1 and feeds that knowledge into a MODFLOW groundwater simulation that includes our watershed.  The model utilizes that United States Geological Service gold standard groundwater numerical modelling code and links it to the open source software iMod. By zooming in to our valley in 3-D it becomes easy to understand the groundwater dynamics. No analysis will get better than this, especially because the AGS is collaborating with the not-for-profit Dutch agency Deltares as a top-gun expert partner.

Applications that will interest SLWSS members include evaluation of the impact of land use changes on groundwater supplies. Pumping more water for domestic and commercial uses than can be replenished by infiltration, then exporting it from the watershed in wastewater will deplete the underground inventory over time. Urbanization of the watershed will also divert more precipitation into stormwater collection systems and export it to the Red Deer River instead of into Sylvan Lake. Those impacts can also be evaluated by combining surface and groundwater flows in an advanced GSFLOW analysis.

The SLWSS has an opportunity for our “Citizen Scientists” to become actively involved with field data collection to support the AGS’ Sylvan Lake project. Monitoring water well levels, and collecting and submitting well water samples for water quality and geochemical analyses, might be needed as the Sylvan Lake project evolves. Rocky View County has already demonstrated that it can be done by involving  its residents in a groundwater project to monitor well water levels.

Sylvan Lake faces increasing development challenges

For years, Bill Carr’s Sylvan Lake cabin was a quiet escape from the hustle and bustle of city life.

Carr has fond memories of visiting the cabin and watching bald eagles, moose and elk from his boat with his children and grandchildren.

“It was very, very peaceful. We’d hear loons on the lake constantly in the evenings,” he said.

As summer in Sylvan nears, locals are bracing for the long lineups of vehicles that congest the roads leading to the lake’s two official boat launches. On hot summer days, the lake is packed.

“The ambience of the lake has really changed,” said Carr, the mayor of the idyllically named Sunbreaker Cove, a tiny village on the lake’s northern shore and one of eight municipal bodies around the lake.

Just 15 minutes from Red Deer and 170 kilometres north of Calgary, Sylvan Lake is a tourist hot spot, with more than a million visitors flocking to the area each year.


Learn to How to Respect Our Lake(s)

The SLWSS invites you to protect Sylvan Lake as a watershed steward.

However Environment and Sustainable Resource Development (ESRD) is more ambitious and invites you to respect all Alberta lakes at the Respect Our Lakes web page.


Know the laws of Canada and Alberta that support lake management goals.

And click on the many links to ESRD’s information resources that are posted here.

Learn how tiny Sylvan Lake fits in to the bigger picture of the Red Deer River watershed and explore the comprehensive State of the Watershed report.

Get to know all the actors who rely on clean water supplies for towns and cities and to meet all their demands for water supply across Central Alberta.

Sylvan Lake is just one of many Central Alberta Recreational Lakes (CARL) that are popular with Albertans. For more information on CARL resources click here.

There’s lots more to our lakes and watersheds, starting with Alberta’s Water for Life strategy.

Wetlands are important.

Resources for students and teachers match the schools curriculum.

It’s easy to learn about healthy aquatic ecosystems. Click here for even more sources of information. Or, see what Cows and Fish say.

The Macrophyte Survey Report Is Out

The first Sylvan Lake macrophyte survey report is posted on the ALMS website.

Here’s how Alyssa Cloutier, our ALMS lake tech in 2014, and marine assistant SLWSS director Devon Shouldice, collected data on aquatic plants that grow in the littoral zone near the lake shore:

The entire perimeter of Sylvan Lake was sampled mainly in 500 m to 1 km intervals. Initially, transects of four points at four different depths were to be taken at each interval. However, the lack of macrophytes even at the shallowest depth prompted a change in methodology. Areas more dominant in macrophytes were sampled more rigorously, with multiple sampling points, while areas with bare or near bare sediment were sampled only once. Voucher samples were taken for each species observed and submitted for archiving at the University of Alberta herbarium.

Here’s what the project found:

Sampling took place on June 26, 2014. Early in the season the lake was very clear, with a Secchi depth of 4.25 m. Aquatic plants were sampled along the littoral zone in water depths ranging from 0.9 m to 5.9 m. Five species were collected and identified. The two dominant species in June were Sheathing Pondweed (Potamogeton vaginatus) and Richardson’s pondweed (Potamogeton richardsonii) with 10 and 8 occurrences, respectively. Of 92 sampling locations, there were 23 occurrences of macrophytes. No invasive species were detected. 

The second sampling trip occurred on July 23, 2014. A secchi disk reading of 4.5 m was observed in the center of the lake. Sampling locations occurred at depths ranging from 0.5 m to 4.2 m. The dominant species in found in June were also the dominant species in July. Over the month of growth, there was an increase in diversity as well as number of occurrences. A larger diversity and density of macrophytes was noticeable in the area just outside the marina, as well as the area in the north portion of the lake where the creek enters. Six more species were observed in July than in June. Of 78 sampling locations there were 62 occurrences of macrophytes (this may include multiple species observed in a single location). Eleven different species were observed. No invasive species were detected.

The SLWSS’ Golf Course Creek 2014 Tributary Project

Here is the project summary:

The watershed tributary Golf Course Creek (GCC) added 1065 kilograms of Nitrogen (analyzed as TN) and 120 kilograms of Phosphorus (analyzed as TP) nutrients to Sylvan Lake in the April-September period of 2014. Total Nitrogen and Total Phosphorus compositions of water quality samples and the measured cumulative flow in the GCC stream were used to calculate lake loading by those nutrients. Flow in GCC was found to be about 12 percent of precipitation incident on the 26.3 square kilometre catchment area after the month of April when snow melt runoff had ceased. Because of mixing of the cumulative GCC flow of about 1.4 million cubic metres of water in the lake volume of 420 million cubic metres, the TP load from GCC increased the equivalent concentration in the lake by about 1.4%.

Click on this hyperlink for the final project report that is available for download.

Tributaries carry stuff from the land into the lake, according to the Second Law of the Watershed. They are important for the future health of the lake, and are targets for water quality control.

See this post for an explanation of the Two Laws of the Watershed.