Water Testing

 

The Davidson Lake Association is working in conjunction with the Department of the Environment NB, The Canadian Rivers Institute at UNB and a group of other Lake Associations in the province to record data relating to our lakes.  At Davidson lake water tests are conducted at five points.  The first four are on the gravel bar separating the two parts of our lake and at three points in the large “upper” portion of the lake.  The fifth and most informative test is the deep hole located in front of the Corey property where the depth of the lake is approximately 27 feet.  This section of the lake is significant.  In the warmest part of the summer when the surface temperature reaches 23-25 degrees, the bottom of this part of the lake remains in the 12-15 degree range and provides an area for some of our fish species to survive. In addition, it has a cooling effect on the surface water.   Three of the other test sites are about 18 feet deep, and the one on the gravel bar is about 6 feet in depth.

Using equipment obtained through funding from the provinces Environmental Trust Fund, water tests are conducted for:

  1. Temperature
  2. Dissolved Oxygen
  3. PH
  4. Conductivity

The first and most important step in a water quality monitoring program is to establish baseline data.  Once this is established, the most critical issue is that the data readings in the lake remain constant.  For this reason it is important to test the water regularly and in a consistent fashion to identify any changes that might occur. Early intervention increases the chance of success in correcting something that is going wrong.

This is a summary, in very general terms, of what we have learned about our lake over the past 4 years:

  • The earliest test in a season was performed in late May. The water was 15 degrees top to bottom.
  • In early July the surface temperature of the lake reaches approximately 23-25 degrees and remains there until late August. During August, this temperature is somewhat constant to a depth of approximately 15 feet.
  • The temperature at the bottom of the ‘deep hole” does not exceed 12-15 degrees at any time. This is a very good thing.
  • In October – November after the lake has “turned over” (water on the surface cools and drops to the bottom) the temperature of the lake drops rapidly and becomes constant for the full depth of 27 feet. The latest test so far was performed in early November and the lake was 7.2 degrees at the surface and 6.8 degrees at the bottom…….and yes; it was very cold performing the test.
  • The dissolved oxygen level throughout the summer is approximately 8 parts per million to a depth of 15 feet then drops rapidly to almost 0 ppm at the bottom of the lake as the incoming spring water contains no oxygen.
  • The PH level of the lake is around 7.5 throughout the summer.
  • Looking over the side of a boat, you can see objects in the lake to a depth of 10-12 feet.

In summary, our lake appears to be healthy.  It remains our duty to keep boat fuel, fertilizers and waste water away from the lake, and most importantly to refrain from doing anything to suddenly and dramatically change the water level.

Your Lake Association welcomes any questions, concerns, or suggestions and is always willing to assist in any way to help ensure that this treasure will be here for our children and grandchildren.  If all Davidson Lake stakeholders work together, we’re confident this can happen.