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 062
The hydrograph above shows the change in ground water level in the observation well (m below ground level) over time.
Observation well 062 is completed in an unmapped, bedrock aquifer to a depth of 76.2 m. Since 1975, the ground water level in the well has ranged from a high of 0.54 m above ground level (flowing) in March 2002, to a low of 43.7 m below ground level in September 2001. The hydrograph shows that ground water levels follow a regular pattern until the year 2000. Maximum ground water levels occur yearly from January to April and minimum ground water levels occur in October and November. The difference between maximum and minimum ground water levels in any single year is quite variable and ranges from a few meters to 44.0 metres after 2000.
This observation well
hydrograph demonstrates a seasonal pattern. Maximum ground water levels occur
in late winter/early spring, corresponding to ground water recharge from seasonal
precipitation, and minimum ground water levels occur in the fall. Extreme minimum
water levels have been observed since 2000, due to interference caused by
the drawdown of a nearby production well. Minimum seasonal water levels occur
during the months of August and September, corresponding to a period of greatest
water demand and ground water pumping.