Observation Well Information

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Introduction

The Province operates a network of observation wells to provide data on ground water level fluctuations and ground water quality information on developed aquifers in British Columbia. Observation well water levels are monitored using one of four methods: 1) manually with a wetted tape, 2) continuously using Steven's chart recorders, 3) electronically with data loggers or 4) remote monitoring using cellphone technology.

Water level data from observation wells are collected on a monthly basis by field observers and forwarded to Regional Offices. Data are then checked for errors and ommissions and forwarded to the Water and Air Monitoring and Reporting Section for final checking and storage. Water level data are referenced from ground level and the month end water level reading are entered and stored in Excel to produce a month-end hydrograph. The method of measurement and accuracy of each method are given below:

Method of measurement Accuracy
Wetted Tape Method +/- 1 mm
Steven's Chart Recorder +/- 1 mm
Data Logger +/- 0.1 %

Observation Well Osoyoos

Hydrograph Analysis- Observation Well No.102

The hydrograph above shows the change in ground water level in the observation well (meters below ground level) over time. This observation well is monitored manually each month using a wetted tape.

Observation well No.102 is completed to a depth of 15.8 m, in the Osoyoos West unconfined, sand and gravel aquifer No. 0193. The aquifer is classified as an IIA (16) aquifer, which is a moderately developed, highly vulnerable aquifer to contamination. Since 1971, the ground water level in the well has ranged from a high of 7.6 m below ground level in September 1972, to a low of greater than 15.9 m below ground level in March 1996. The ground water level reached the bottom of the well (15.9 m) between 1990 and 1996. The difference between maximum and minimum ground water levels in any single year ranges from approximately 1.0 (in 1989) to 6.0 (in 1972) metres. The range may be possibly larger in 1993 as the ground water level fluctuates below the bottom of the well.

Ground water levels in this well generally follow a regular pattern due likely to snowmelt and/or to recharge from irrigation return flows. The hydrograph shows an increase of ground water at the start of the irrigation season, reaching maximum levels in September and October. Ground water levels then decline to reach minimum levels in March, April and May, as irrigation recharge ceases. Interference due to the pumping of nearby well(s) was evident between 1990 to 1996. During those years, ground water levels reached the bottom of the well. This observation well may also respond to lake level fluctuations, as the well is located 100 m from Osoyoos Lake.

 

NOTE* Detailed water level information for this well is available in Excel Format.
For more information, please email
groundwater@gov.bc.ca