Does this picture look familiar? Anyone who has been to Lake Eau Claire knows exactly the feeling that the person who took this picture shared, yuck. Phosphorus is one the of the main reason for algae growth. Phosphorus is brought into lakes through tributaries and turnover from sedimentation on the bottom of the lake.

By: Dan Carey

How can I convert the data to useable figures regarding total lake area or volume?

What ways can I represent the result?

How can I measure and calculatethe amount of water leaving the basin?

How can I measure and calculate the amount of water leaving the basin?

What factors needed to be measured and taken into account to know about the volume of the lake?Where is the most phosphorus comingfrom, the sediment or the tributaries?

The lake has water quality problems and it has to do mainly with chlorophyll and phosphorus.

Lake Eau Claire annually has a very large abundance of algae growth every year.This can be because of the pollutants that are introduced by the following tributaries: Hay Creek, Muskrat Creek,and the Eau Claire River.Lake Eau Claire is a basin, so it has a faster than normal turnover rates when it come to lakes.

When the water is entering and leaving the basin, that turnover/flow causessediment to be kicked up, introducing “old” pollutants back into the lake.

The most common habitat that the tributaries wind through is mostlyagricultural areas and county forest.

Also, two out of the three tributaries have quite poor water quality at the mouth: Muskrat creek the North Fork of the Eau Claire River.

The next mission I had was to find the volume of the lake so that I could use it tocalculate the loading and “unloading”of Phosphorus and sediment. So I took a map of Lake Eau Claire and cut out each depth of the lake. Then I set up proportionsthat had to deal with the known size and the weight out of a whole of the sections ofthe lake.

After this, it was time to start getting tests done for phosphorus and inflow/outflow. So I went to four designated sites, which will be specified later, and I took bottles filled them upand I took the flow with the flow meter at each site.

After I finish all of the outdoor testing, then it was time for a the long, drawn outindoor testing for phosphorus. The directions for the procedures came from the “HACH Test ‘N Tube procedures”packet. I went out to test, then came back to finish it 7 times.

Field methodswere quite simple.The first of the two, the flow meter, was turned on and the propeller end was stuck in the water and I waited till the ft/sec speedstopped going up, and then I would mark it down. The second thing I would do wouldbe to fill up two bottles per site, with water, and mark down the number on the bottle.

This object is a flow meter whichmeasures how fast the water is moving infeet per second. It is hooked up to a graphing calculator which displays the speed.

Sample bottles wereused to hold samplesof water from each ofthe four sites so that they could be taken back to the lab to betested for phosphorus.

The labs methods weren’t quite as simple.I had to follow theHach Test n’ Tube P Testing step by step.This process, in a whole, took about 2 hoursto complete. Sediment testing took a couple of days to complete.

The Hach AnalyticalProcedures Test n’ Tube Phosphorus TestingManuel was used forthe procedures for testing for phosphorus when the samples were taken back to the lab.

This is theSpectrophotometerand it is usedfor measuringhow “turbid”or how much phosphorus ispresent in a solution by shooting light waves through itand seeing how able the waves are to getthrough.

The Hach test tubeswhere used in holding the samples and the chemicals needed to test phosphorus. I used 12 test tubes, 3 for each site, to geta better average of phosphorus for each site.

These HachTest n’ Tubechemicals were usedin the testing process. The following chemicalswere used:Potassium Persulfate, PhosVer PhosphateReagent, Sulfuric Acid, and Sodium Hydroxide.

Site Area In2 Area ft2 flow ft/sec flow vol ft3/sec In1 4128 28.66666667 1.043 29.89933333 151.58 ft3/sec2 516 3.583333333 4.62 16.555 Out3 15402 106.9583333 1.9 203.2208333 203.22 ft3/sec4 17202 119.4583333 0.88 105.1233333

11/6/03

Outflow Turnover in Sec. O.T. in Days14808816.01 171.3983334

12/10/03Site Area In2 Area ft2 flow ft/sec flow vol ft3/sec In

1 4128 28.66666667 1.79 51.31333333 169.99 ft3/sec2 516 3.583333333 5.65 20.24583333 Out3 15402 106.9583333 1.79 191.4554167 191.46 ft3/sec4 17202 119.4583333 0.824 98.43366667

Inflow/Outflow

1/13/04Site Area In2 Area ft2 flow ft/sec flow vol ft3/sec In

1 4128 28.66666667 2.51 71.95333333 202.975 ft3/sec2 516 3.583333333 0.56 2.006666667 Out3 15402 106.9583333 1.35 144.39375 144.394 ft3/sec4 17202 119.4583333 1.08 129.015

3/24/04Site Area In2 Area ft2 flow ft/sec Flow vol ft3/sec In

1 4128 28.66666667 2.43 69.66 213.15 ft3/sec2 516 3.583333333 5.34 19.135 Out3 15402 106.9583333 3.24 346.545 346.55 ft3/sec4 17202 119.4583333 1.041 124.356125

Inflow/Outflow

Site Area In2 Area ft2 flow ft/sec flow vol ft3/sec In1 4128 28.66666667 3.79 108.6466667 277.56 ft3/sec2 516 3.583333333 6.8 24.36666667 Out3 15402 106.9583333 2.76 295.205 295.21 ft3/sec4 17202 119.4583333 1.21 144.5445833

4/14/04Site Area In2 Area ft2 flow ft/sec flow vol ft3/sec In

1 4128 28.66666667 2.79 79.98 235.99 ft3/sec2 516 3.583333333 5.2 18.63333333 Out3 15402 106.9583333 2.51 268.4654167 268.47 ft3/sec4 17202 119.4583333 1.15 137.3770833

Inflow/Outflow

Loading EstimatesDay 1 11/6/03

MGD Mg/L LBS/DaInflow 97.92068 0.177 144.5485494

Outflow 131.28012 0.08 87.59009606

Day 2 12/10/03MGD Mg/L LBS/DA

Inflow 109.81354 0.1727 158.1664183

Outflow 123.68316 0.07 72.20622881

Day 3 1/13/04MGD Mg/L LBS/DA

Inflow 131.12185 0.456 498.6616404

Outflow 93.278524 0.123 95.68697549

Phosphorus Loading

Day 4 3/24/04MGD Mg/L LBS/DA

Inflow 137.69 0.19 218.183574

Outflow 223.87 0.04 74.683032

Day 5 3/25/04MGD Mg/L LBS/DA

Inflow 179.69 0.15 224.79219

Outflow 190.71 0.06 95.431284

Day 6 4/14/04MGD Mg/L LBS/DA

Inflow 152.45 0.16 203.42928

Outflow 173.43 0.12 173.568744

Phosphorus Loading

LBS/Day Phosphorus Loading

0

100

200

300

400

500

600

11/6

/03

11/1

3/03

11/2

0/03

11/2

7/03

12/4

/03

12/1

1/03

12/1

8/03

12/2

5/03

1/1/

04

1/8/

04

1/15

/04

1/22

/04

1/29

/04

2/5/

04

2/12

/04

2/19

/04

2/26

/04

3/4/

04

3/11

/04

3/18

/04

3/25

/04

4/1/

04

4/8/

04

Dates

LB

S/D

ay

Inflow

Outflow

I conclude that the inflow of phosphorusinto the lake is much greater than that leaving the lake. The highest rate of flow is spring time, and it is more of a gradual thing during the times of summer, fall, and winter. Winter is the lowest time.