The Ground Water Section of the Ministry operates a network of 163 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 064
The hydrograph above shows the change in ground water level in the observation well (m below ground level) over time.
Observation well 064 is completed in an unmapped, bedrock aquifer to a depth of 161.5 m. Since 1974, the ground water level in the well has ranged from a high of 1.8 m below ground level in February 1991, to a low of 4.2 m below ground level in July 1975. The hydrograph shows that ground water levels follow a regular seasonal pattern. Maximum ground water levels occur yearly during March and April and minimum ground water levels occur in October and November. The difference between maximum and minimum ground water levels in any single year ranges from approximately 0.5 to 2.2 metres.
This observation well demonstrates
a seasonal pattern. Maximum ground water levels occur in early spring, which
correspond to ground water recharge from seasonal precipitation, and minimum
ground water levels occur in late fall. There appears to be a drop in ground water
levels in 1991; the ground water levels remain at the lower level in a steady
state until the end of the recording period. The observation well was abandoned
in 1998 due to the high mineral content of the water.