Flipside Kids Learn About Water Quality

This Sylvan Lake News story was published in the April 20 edition:

Children involved in the drop-in programs at the Flipside Youth Centre were taught some things about that big body of water at the north end of town, on April 13.

President Graeme Strathdee and Director-at-Large Susan Samson of the Sylvan Lake Watershed Stewardship Society gave an interactive presentation on the science surrounding the waters of Sylvan Lake.

Both representatives provided various examples of what affects water quality in the lake, as well aswhat procedures are used to test the quality of that water, such as pH testing.

“They talked to kids on how they do testing for farm runoff, and what comes out of rainwater thatends up in the lake,” said Deshon Lennard an FCC Youth Services Coordinator with the Town ofSylvan Lake.

Lennard said that in their presentation, Strathdee and Samson explained all the factors that affectthe lake, from tourist activity to bacteria from garbage. Their presentation also had a hands-onaspect, with children carrying out experiments that tested tap water quality.

“The kids got to do a scaled down version of the larger activities, with one simulating the types ofwater in the lake with cups,” said Lennard. “Each cup represented geographic areas in the lake, andthey used food colouring to differentiate the distinct areas of the lake.”

Lennard said that last Thursday’s session was part of a larger educational segment of the youthcentre’s programming called Power-up Thursday, whereby children engage in educational activities,that “engage them in diverse areas of science and math.”

“The kids were very interested and curious,” said Lennard. “They learned something new, and tooksome pride in learning about the water in the lake, because they’re from here.”

Our Stewardship Science message was built around this slideshow of water quality sampling of Sylvan Lake and Golf Course Creek.

DSC_0123

Can you collect a composite sample of lake water like Breda is doing? Flipside kids can.

Thanks to Sam Macdonald, new SLN reporter just arrived from NS, for the reprinted story.

 

 

Status Report on Sylvan Lake Water Quality in 2016

This is an interim report on the results of Sylvan Lake  water quality sampling between May and September 2016. Previous posts have illustrated the joint SLWSS-ALMS project in action on the high seas. The teamwork of ALMS lake technician Breda Muldoon, able crew members from the SLWSS, and boat captain Ed Thiessen of Norglenwold allowed us to complete three of the planned five sampling cruises. Two were abandoned because of unsafe weather conditions.

The official LakeWatch report on the Sylvan Lake 2016 campaign will be issued by the Alberta Lake Management Society in mid-2017 according to the standards and schedule of that program.

Meanwhile, some of the raw data analyzed by Maxxam, the certified commercial laboratory in Edmonton, are available for inspection and preliminary interpretation. This table summarizes the constituents in Sylvan Lake water. The list includes naturally occurring cations and anions that are transported from the land into the lake over time in groundwater, precipitation and atmospheric fallout. In addition, the indicator nutrients nitrogen and phosphorus are measured to determine the eutrophic condition of the lake.

We were surprised to discover that the Total Phosphorus (TP) concentrations fell at the low end of the historical range on this histogram of data from three decades of water quality analyses:

wq-histogram-2016

Those TP values in the range 0.010 to 0.015 milligrams per litre (that is, ten to fifteen parts per billion) were well below the eutrophic limit threshold guideline for Sylvan Lake of 0.035 mg/L, or 35 ppb. Note that the historic TP median concentration has been about0.021 milligrams per litre, or 21 ppb. That is the source concentration of phytoplankton fertilizer feed.

We use TP as an indicator or quick index to estimate the potential for phytoplankton growth and appearance of algal blooms that are common at other nutrient-rich Alberta lakes like Pigeon and Pine lakes.

The 2016 data suggested that the food chain in the lake might be adversely affected by too little nutrient content. If single-celled phytoplankton don’t grow, and produce food for zooplankton and the higher members of the food chain then aquatic health of the fish stock can become jeopardized by being placed on a low-calorie diet.

We observed that directly with the simple Secchi disk test for water clarity. Through the sampling period, the disk typically remained visible down to a depth of 5 metres, indicating that there was not much light-scattering suspended material in the water column.

Part of the explanation for the depleted nutrient concentration in 2016 undoubtedly was the absence of significant snowmelt runoff until mid-May. Generally initial runoff carries high concentrations of nutrients into the lake. After plants start growing on the land those nutrients are captured and retained and become less available to reach the lake. Here is the precipitation history for the January-September period using Alberta Agriculture data from the Hespero weather station west of the watershed.

hespero-weather-2016-01-to-09

Intermittent soil-saturating precipitation of >10 mm/day (the tiny blue spikes) tends to activate surface flow into tributaries and creeks that discharge into the lake. The red cumulative precipitation line did not cross the long-term average until September, after which nutrient concentrations do not contribute to concerns about excess cosmetic algal growth.

A customized addition to the 2016 campaign was the collection of water samples from within the top 1 metre and the bottom 1 metre of the lake at its deepest sample station. The purpose was to detect any elevated TP concentration above the sediment from decay of nutrient-rich material previously settled out of the water column. Previous studies of Sylvan Lake have demonstrated that enriched layer. However, our chemical analyses in combination with the relatively constant instrumental measurements with depth of conductivity, temperature and dissolved oxygen suggested that the chance of substantial nutrient mixing was low through the open water period of 2016. That conclusion assumes that conditions at other deep locations above the lake sediment are no worse that what we observed at the reference station.

 

 

 

 

 

Sylvan Lake Precipitation and Stormwater Runoff in 2015

How much precipitation has fallen on the watershed in 2015? Has is been lower, higher or about average?

The answer, according to data from Alberta Agriculture’s Hespero weather station west of Sylvan Lake we have received just about the typical historical amount. This graph shows the 2015 cumulative precipitation (red) compared to the average curves for the Hespero (blue) and Red Deer Airport (yellow) weather stations. Click to enlarge the figure:

Hespero Precip 2015-01-01 to 08-17

Because of the wide range of precipitation at points on the ground the 2015 curve is just representative. In Alberta, incident rain can very significantly within short distances. Still, over time it averages out. We will continue to use the Hespero station as our reference as it is generally upwind of the watershed and cloud systems tend to blow in from the west. The Alberta Agriculture database does not report annual accumulated precipitation for the Lacombe Airport.

What do the data mean? We have received a little more than 35 cm of precipitation since the beginning of the year.

If we only look at the data since May 1:

Hespero Precip 2015-05-01 to 08-17

rain has fallen intermittently with lengthy dry periods in between. Those 20-30 mm rains have caused excitement and they have tested the Town of Sylvan Lake’s stormwater system. The strip-mined areas of town, the land under development at the south end, have been susceptible to erosion and runoff that has caused Golf Course Creek to become turbid as reported in a separate post.

Once solids become suspended in a flowing or turbulent water body there are two solutions to restore water clarity:

(1) Slow down the flow and allow the particles to settle according to Stokes’ Law. Heavier coarse particles settle rapidly. Very fine ones like clays can take decades. Stormwater detention ponds are supposed to provide extra settling time just like tailings ponds do at mining operations.

(2) Apply separations technologies like thickeners, cyclones, centrifuges and filters to speed up the separation. Non toxic flocculants can be added to increase particle size by agglomeration and to increase the Stokes’ Law settling rate.

Of course if eroded particles are prevented from entering the stormwater system at the source then Sylvan Lake’s water will remain clear as an elementary school student reminded us:

FRS-Jade T-Kendall-v2

Contaminating water bodies can be a serious offense under Alberta’s Water Act. The best practice is not to let it happen.

Heavy Rains Erode Soil and Contaminate Sylvan Lake

1-DSC_0056 2-DSC_0051 3-DSC01214

Recent heavy rains have caused erosion of construction sites in the Town of Sylvan Lake (TSL) and transported fine particulates into the lake through the stormwater system and Golf Course Creek. The flow discharges into Marina Bay and then into the lake as a plume of very fine suspended solids that cause water quality to deteriorate as these photo show.

The TSL’s investigation of the source of the release was reported to Council at the August 8 meeting. Clearly there is scope for improved containment of runoff from construction sites in the watershed and stronger regulatory action with appropriate penalties.

Alberta’s Hotline for citizen reporting of contaminant releases is:

Energy & Environmental Response Line

24 Hour Hotline: 1-800-222-6514

This case history is further proof that the Two Laws of Watersheds really do apply in the real world:

  • Water flows downhill
  • Stuff from the land ends up in the lake

Who’s putting all that CO2 into the air?

NASA’s mission team for the recently launched OCO-2 satellite has reported preliminary results on its performance and on observations of the atmosphere at the American Geophysical Union conference in San Francisco . The goal is to map carbon dioxide concentration in the vertical column of air between the ground and the OCO-2 satellite, and to detect sources and changes of CO2.

Here is the NASA press release about the paper presented today:

Early Results from NASA’s Orbiting Carbon Observatory-2 Mission
Time: Thursday, Dec. 18, 9 a.m. PST
In 2014, NASA launched four new missions to study our home planet, including the Orbiting Carbon Observatory-2 in July – NASA’s first mission dedicated to studying atmospheric carbon dioxide. This press conference will present early results from the OCO-2 mission. Fossil fuel combustion, deforestation and other human activities are adding almost 40 billion tons of carbon dioxide to the atmosphere each year, yet less than half of it stays airborne. The rest is apparently being absorbed by natural processes at the surface, whose identity and location are poorly understood. Ground-based carbon dioxide measurements accurately record the global atmospheric carbon dioxide budget and its trends but do not have the resolution or coverage needed to identify the “sources” emitting carbon dioxide into the atmosphere or the natural “sinks” absorbing this gas. One way to improve the resolution and coverage of these measurements is to collect precise observations of carbon dioxide from an orbiting satellite. OCO-2 is NASA’s first satellite designed to measure atmosphere carbon dioxide with the accuracy, resolution and coverage needed to identify its sources and sinks. OCO-2 is currently recording more than 100,000 carbon dioxide measurements over Earth’s sunlit hemisphere each day. In addition, a new data product from OCO-2 that senses light emitted from the photosynthesis of plants has been developed. Over the next two years, these measurements are expected to revolutionize our understanding of the processes controlling the atmospheric buildup of carbon dioxide.

Graphics for the presentation are posted here.

The OCO-2 mission web page will post data after December 30, 2014.

NASA’s older MODIS satellite, launched in 1999, collected data on chlorophyll fluorescence from the massive algal bloom at the west end of Lake Erie last August. Read about the space-based monitoring of the rapid growth of the toxic phytoplankton bloom from an orbit 705 km above the Earth. Here is the explanation excerpt from NASA’s Giovanni News:

Conditions in the western end of Lake Erie at the end of July 2014 were perfect for the cyanobacteria Microcystis, a toxic phytoplankton species. High water temperature, low wind speeds, and an elevated nutrient load from higher-than-normal spring runoff set the stage for this disruptive event.

In principle, the higher resolution of satellite successors to OCO-2 might eventually enable detection of changes in the condition of Sylvan Lake although it is a small 42 square kilometre target. Until that high tech monitoring is demonstrated and validated, our own ground-based observations (look out your window, over the side of your boat, dip in your Secchi disk, or send a sample to the lab for Chlorophyll-a analysis) will still have to trigger the alarm for cyanobacterial blue-green algae blooms in Sylvan Lake.

The Level of Sylvan Lake Today Is…….

Click here to view the level of Sylvan Lake and the trend as evaporation takes over after July 1.

Lake level data are logged continuously and reported on that Alberta Environment web page.

Can you calculate how much water is lost daily at this time of year?

 

 

Total Precipitation and Sylvan Lake Level

Sylvan Lake watchers have conflicting personal opinions about lake level. This post presents some facts about the one factor that causes the lake level to rise: the Total Precipitation that falls on the watershed area each year. Other factors cause the lake level to drop, particularly seasonal evaporation and transpiration from land, crops and foliage that is measurable after about July 1 each year.

An understanding of these historical data is important to the debate about control of the level of Sylvan Lake for the convenience of lake users. The simplest fact to know is that the watershed receives about 500 mm (half a metre) of precipitation annually. Statistically, the yearly values are typically within +/- 10 percent of 500 mm about 70 percent of the time. In the other more extreme years the total precipitation can differ as much as +/- 30 percent of the average.

The fate of that water determines if the lake level goes up or down. To calculate how much water is in play multiply the area of the watershed (106 million square metres) by the 0.5 metre of annual total precipitation. Of the 53 million cubic metres of water that is typically delivered by weather systems, most evaporates, or else it infiltrates and is stored as groundwater.

The Red Deer Airport has collected and recorded those weather data for many decades and provides quality-controlled history that is representative of conditions here in Central Alberta. Those data are used to create the following graphs.

As there is no weather station in the Sylvan Lake watershed we do not have data for the 106 km2 of the area. Other weather stations have reported data at locations within 50 km of Sylvan Lake however records have been neither continuous nor quality controlled to national meteorological standards.

For a more comprehensive regional analysis of precipitation and evaporation see the Edmonton-Calgary Corridor Groundwater Atlas.

Annual Precip-RDA-1940 to 2011

Total precipitation recorded at the Red Deer Airport since 1940. Source: Environment Canada’s climate data.

Precipitation Anomaly-RDA-1940-2012

This graph shows how annual amounts of Total Precipitation have varied when compared to the 71-year average.

Change in Total Precip Y-to-Y 1940-2011

From year to year Total Precipitation has behaved unpredictably. One year it can be very high, then the next year we can have drought-like conditions. Trends are not evident in the 71-year record.

Cum Precip vs Cum Time 1971-2000

In any year the Total Precipitation has an “S-Shaped” characteristic as this graph shows. The middle 40% of the year delivers about 70% of the precipitation. The points in this graph are average values calculated from 31-years of data.

Alberta Environment and Sustainable Resource Development provides continuous reports on the level of Sylvan Lake.

Since the beginning of July the level had dropped about 150 mm over 60 days. That’s a rate of 2.5 mm per day, and it means that more than 100,000 cubic metres a day evaporate! That is typical of the post-July 1 lake level response during the last decade.

Evaporation is driven by high Temperature (T) and low Relative Humidity (RH) conditions, and wind velocity. Sylvan Lake does not have a dedicated weather station, however hourly data logged at Hespero on Highway 11, just west of the watershed. You can retrieve and view the records on this Alberta Agriculture website. The T and RH data for each of the four 2013 months from May to August are shown in this graphic.

Regional precipitation recorded at the Red Deer Airport and other Environment Canada weather stations has been reasonably consistent in the last decade. The S-curve form of the cumulative precipitation curve through a year is presented in the linked graph. Note that about half of the annual precipitation occurs before July 1. Direct rain onto the lake surface plus runoff from the land and groundwater inflow cause the lake level to rise. After July 1, at 50% of the year, the rate of evaporation exceeds the incoming precipitation and the lake level traditionally drops.