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 053
The hydrograph above shows the change in ground water level in the observation well (m below ground level) over time.
Observation well 053 is completed in an unmapped aquifer to a depth of 15.2 m. Since 1966, the ground water level in the well has ranged from a high of 0.5 m below ground level in March 1983, to a low of 4.9 m below ground level in December 2001. The hydrograph shows that ground water levels follow a regular seasonal pattern, with maximum ground water levels occurring yearly during April and May and minimum ground water levels occurring in December, January and February. The difference between maximum and minimum ground water levels in one season ranges from approximately 0.5 to 3.0 metres.
This observation well demonstrates a seasonal pattern with maximum ground water levels occurring in the spring and minimum levels occurring in late winter. Maximum ground water levels in the spring may be attributed to the annual spring snowpack melt. Year to year variability of maximum ground water levels depend on the timing of the snow melt.