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 047
The hydrograph above shows the change in ground water level in the observation well (m below ground level) over time.
Observation well 047 is completed in an unmapped, bedrock aquifer to a depth of 91.4 m. Since 1966, the ground water level in the well has ranged from a high of 0.5 m below ground level in May 1969, to a low of 10.6 m below ground level in May 1975. The hydrograph shows that ground water levels follow a regular seasonal pattern, with maximum ground water levels occurring yearly during May and June and minimum ground water levels occurring in March and April. The difference between maximum and minimum ground water levels in one season ranges from approximately 2.0 to 9.5 metres. Ground water levels for this well have remained stable over the long-term.
This observation well may be influenced by seasonal irrigation. Water intake for irrigation purposes increases during spring, creating low ground water levels in the well. Ground water levels are then recharged in the summer by the infiltration of irrigation water back into the aquifer.