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 %

Hydrograph Analysis- Observation Well No. 101

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 each month, manually using a wetted tape.

Observation well No. 101 is completed to a depth of 19.5 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 1969, the ground water level in the well has ranged from a high of 2.0 m below ground level in June 1995, to a low of 9.3 m below ground level in April 1979. The difference between maximum and minimum ground water levels in any single year ranges from approximately 1.0 (in 1971) to 6.5 (in1979) metres. Ground water levels in this well generally follow a regular pattern due likely to snowmelt and recharge from irrigation return flows. The hydrograph shows an increase of ground water at the start of the irrigation season, reaching maximum levels in late August and September. Ground water levels then decline to reach minimum levels in March and May. There is some erratic behaviour in the hydrograph, which may be due to pumping interference from surrounding wells. The observation well may also respond to Osoyoos Lake level fluctuations.


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