Gardom Lake Monitoring Results to November

2012

January 20, 2015Salmon Arm

Dennis EinarsonMinistry of Environment

Overview

• Monitoring: Why and What

• Lake Processes and Limnology

• Monitoring Results

• Next Steps and Lake Management Suggestions

Monitoring: Why and What

LAKES IN GENERAL PLAY AN IMPORTANT ROLE IN OUR LIFES AND ARE IMPORTANT ECOSYSTEMS:

• RECREATION (e.g. boating, fishing, swimming, viewing)

• DOMESTIC WATER USE (e.g. drinking water, irrigation)

• COMMERCIAL WATER USE(e.g. livestock watering, industrial process water, fisheries, storage, transportation)

• ECOSYSTEM(e.g. habitat for wildlife, part of watershed, nutrient storage, pollutant sink)

• Understand natural and/or current lake character and condition

• Identify lake sensitivity to nutrient inputs and other anthropogenic effects

• Identify existing problems

• Educate Residents, Developers and Decision Makers

WHAT/HOW

• Water Temperature Profile

• Dissolved Oxygen Profile

• Conc.: metals, ammonia, nitrite, chloride, bromide, pH

• Secchi Depth

• Nutrient concentration

INFORMATION

Lake Stratification

Conditions for Aquatic Life

Water clarity/Productivity

Potential Lake Productivity

Nutrient concentrations and lake productivity

10

Lake Processes & Limnology

Productive Lake

Nutrient Poor Lake

To understand what happens in Gardom Lake,

We need to understand how each of the measured factors influence water quality and lake productivity.

Seasonal Lake Stratification

• Solar heating effects water temperature water density.

• Denser water is heavier, thus will stay at the lake bottom.

Stratification Summary

0.00 2.00 4.00 6.00 8.00 10.00 12.00

0

5

10

15

20

2.00 6.00 10.00 14.00 18.00 22.00 26.00

DO (mg/L)

Dep

th (

m)

Temperature ( C)

Gardom L East, 2007-11-06

Temp

DO

Monitoring Results

0.00 2.00 4.00 6.00 8.00 10.00 12.00

0

5

10

15

20

2.00 6.00 10.00 14.00

DO (mg/L)

Dep

th (

m)

Temperature ( C)

Gardom L East - Apr 27/09

Temp DO

24

25

26

Current Conditions

• pH

• Metals

• Ions

• Fecal Indicator

Good range for fish

Manganese - > aesthetic Drinking Water Guideline

Bromide – = > Drinking Water Ozonation Guideline – this may be a false positive. No other values exceed.

Ammonia – at Aquatic Life Guideline once at bottom

Fecal Coliforms – <10 units/100mL, > Raw DW GL

Summary Conditions for Aquatic Life/Fish/Humans

Oxygen levels in deeper water too low for fish

Water chemistry not problematic for fish

Bromide levels slightly too high for OzonationTreatment

Treat raw water for bacteria before drinking

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

2005 (n=18) 2006 (n=17) 2007 (n=31) 2008 (n=24) 2010 (n=13) 2011 (n=12) 2012 (n=13)

Secc

hi d

epth

(m

)Gardom Lake Secchi Summary 2005 - 2008 & 2010 - 2012

Minimum Average Maximum

Oligotrophic

Mesotrophic

Eutrophic

0

5

10

15

20

25

30

35

24-Apr-90

09-Apr-91

09-Apr-92

09-Apr-93

09-Apr-94

09-Apr-95

09-Apr-96

09-Apr-97

09-Apr-98

28-Apr-99

18-Apr-00

28-May-01

01-May-02

30-Apr-03

30-Apr-04

30-Apr-05

30-Apr-06

12-Apr-07

24-Apr-08

27-Apr-09

25-Mar-10

12-Apr-11

25-Apr-12

TD

P/T

P c

on

ce

ntr

ati

on

(µ

g/L)

Gardom Lake Total Dissolved Phosphorus & Total Phosphorus at spring overturn 1990 to 2012

TDP (µg/L)

TP (µg/L)

Oligotrophic

Mesotrophic

Eutrophic

2010 452011 92012 33

0

10

20

30

40

50

60

70

80

90

100

24-Apr-90

09-Apr-91

09-Apr-92

09-Apr-93

09-Apr-94

09-Apr-95

09-Apr-96

09-Apr-97

09-Apr-98

28-Apr-99

18-Apr-00

28-May-01

01-May-02

30-Apr-03

30-Apr-04

30-Apr-05

30-Apr-06

12-Apr-07

24-Apr-08

27-Apr-09

25-Mar-10

12-Apr-11

25-Apr-12

TD

P/T

P c

on

ce

ntr

ati

on

(µ

g/L)

Gardom Lake Total Dissolved Phosphorus & Total Phosphorus Hypolimnion at spring overturn 1990 to 2012

TDP (µg/L)

TP (µg/L)

General Characteristics

Oligotrophic Mesotrophic Eutrophic

Productivity Low Intermediate High

Total Phosphorus Levels

1-10 µg/L 10-30 µg/L

Gardom Lk

>30 µg/L

Secchi Depth > 6 m 3-6 m

Gardom Lk

0-3 m

Trophic Status

Lake sensitivity to nutrient inputs and other anthropogenic effects

• Bottom Water acts as Nutrient Sink, but keeps Nutrients in the water column.

• MODERATELY SENSITIVE

• Lake Stratification

• Condition for Aquatic Life/Human use

• Lake Productivity

• Sensitivity to Nutrient input

All Summer, Winter, Spring

Low oxygen levels below 5-10m depth

bromide levels > ozonationguidline

Mesotrophic, high nutrient levels at bottom

Moderately Sensitive

Summary

Next Steps ?

• Minimize the disturbance of shoreline areas –keep natural vegetation cover.

• Limit the use of fertilizers and pesticides, particularly not during rain.

• Manage septic systems.

Management Suggestions

E. Dennis Einarson RPBioEnvironmental Protection Division

Thompson Region1259 Dalhousie Drive

Ph: 250-371-6200