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 078
The hydrograph above shows the change in ground water level in the observation well (m below ground level) over time.
Observation well 078
is completed to a depth of 9.4 m in aquifer 124, a volcanic bedrock aquifer.
The aquifer is classified as a IIIB(II), lightly used and moderately vulnerable
to contamination from the land surface. Since 1972, the ground water level
in the well has ranged from a high of 0.2 m below ground level in March 1997,
to a low of 4.5 m below ground level in January 1984. The hydrograph shows
that maximum ground water levels generally occur in March, April and May corresponding
to ground water recharge from seasonal precipitation, and minimum ground water
levels generally occur in January and February. The difference between maximum
and minimum ground water levels in any single year ranges from approximately
1.5 to 3.5 metres.
Local pumping interference may influence ground water levels in this observation well. Small data gaps exist within the recording period, especially from 1972 to 1983, obscuring possible trends.