Eagle Lake Property Owners' Association
......what you can do today
         to help preserve Eagle Lake for tomorrow
Eagle Lake Water Quality Status ~ 2015
Results obtained through the Watershed
Watch program of the Rideau Valley
Conservation Authority are tabulated below.
In most years, five points on the lake (sites A,
B, F, G, and the deep point (DP) on the
adjacent map) are sampled for two chemical
parameters and E. coli contamination. In
addition at the deep point, dissolved
oxygen/temperature profiles are obtained in
order to assess lake trout habitat. Such
testing occurs three to four times each season
from May until September.
Contact: eaglelake@bell.net
Copyright © 2015
Eagle Lake Property Owners' Association

HomeBoard of DirectorsConstitutionAdvertisersContact
At five year intervals, seven other shoreline
sites are tested (green dots and additional red
dots). These were last done in 2012 and all
results indicated excellent water quality

As part of the RVCA Watershed Watch Program, water samples were obtained from four shoreline
sites and the deep point at Eagle Lake from May until October 2015 (see summary table below). In
addition, two further water samples were taken in both July and August, one at Treasurer (Middle)
Island (a site often used by RKY Camp) and the other at the upper end of Curl's Bay. Analysis for
phosphorus and nitrogen produced results that were well within the Ontario standards at all locations
and no significant E. coli bacteria counts were detected (see table).

No Zebra mussel larvae or spiny waterflea were detected in 2014 and water samples to check for
these invasive species were again obtained in July 2015 from Parham and Hampton Landings.


Results for the 2015 season
A. Eagle Lake

Tests at Eagle Lake
Range
Average
No of Tests
Standards
Total Phosphorus (micrograms/litre)
5 to 11
8
12
20
Total Nitrogen (micrograms/litre)
200 to 380
263
12
500
E. coli (cfu/100ml)
<2 to 10
3
8
100
Calcium (milligrams/litre)
 
14.1
1
20

Tests at Leggat Lake
Range
Average
No of Tests
Standards
Total Phosphorus (micrograms/litre)
7 to 13
10
10
20
Total Nitrogen (micrograms/litre)
190 to 580
349
10
500
E. coli (cfu/100ml)
<2 to 4
2
10
100
Calcium (milligrams/litre)
 
9
1
20
The usual testing that was done at the deep
point on four occasions in 2015 to measure
the dissolved oxygen and temperature in the
deep cold water zone indicated a quite good
habitat for Lake Trout this year, especially in
the important period from mid-August until
the end of September (Figure 1). In fact, an
additional calculation based on this data
confirms that oxygen levels in the Lake
Trout habitat have been close to or ideal in
the past two years, something uncommon
for Eagle Lake (for additional information
see the “Fishery Management” section of
the State of the Lake Report - Update
2015 using the link on the Home Page)
Figure 1. Lake Trout habitat as annual dissolved oxygen (DO) and temperature profiles at the deep
point of Eagle Lake taken between May 20th and October 9th, 2015. The pink zone represents the
lake depth with optimal conditions (<10°C and 7 mg/L dissolved oxygen) and the light blue zone with
usable conditions (<15°C above the pink zone and 4 mg/L of dissolved oxygen below the pink zone).
The depth of the optimal zone on August 28th represents quite ideal conditions, especially for juvenile
trout.
B. Leggat Lake
Water quality testing at Leggat Lake, again as part of the RVCA Watershed Watch Program, was
performed on four occasions between May 14th and October 28th, 2015. The majority of the test
results were well within the standards (see Table below), except for one result for total nitrogen at 580
micrograms/litre. However, the average value of 328 micrograms/litre indicates that this is not a
persistent finding.

Zebra Mussel larval forms have been noted in water samples from Leggat Lake in 2013 and 2014.
However, since calcium levels are quite reasonable (average of 9 milligrams per litre) and this species
requires in the order of 20 milligrams/litre of calcium to mature to the adult stage, it is unlikely they will
become established. Testing at the lake should be carried out this summer to confirm absence of adult
Zebra Mussels.