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 %

Mayne Island observation well graph

Hydrograph Analysis- Observation Well No.126

The hydrograph above shows the change in ground water level in the observation well (meters below ground level) over time. Well water level measured by a Steven's recorder, monitors the ground water level fluctuations in this observation well.

Observation well No.126 is completed to a depth of 71.0 m in an undelineated, bedrock aquifer. The ground water level in the well has ranged from a high of -1.16 m above ground level in March 1980, to a low of 0.22 m below ground level in August 1973. The difference between maximum and minimum ground water levels in any single year ranges from approximately 0.4 (in 1976) to 1.2 (in 1973) meters. The hydrograph shows that ground water levels in this observation well follow a regular seasonal pattern. Maximum ground water levels occur in January, February and March, corresponding to ground water recharge from seasonal precipitation, and minimum ground water levels occur in the months of August, September and October. Ground water levels for this observation well were rising from 1974 to 1978, and have generally remained at a steady level to the year 2002.

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