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The following provides an overview of groundwater conditions in the West Coast Region.

This report was generated on August 01, 2025.

Background

The province maintains a network of groundwater observation wells to monitor water levels in priority aquifers. These observation wells (OW) record water level fluctuations which allow for improved understanding of how aquifers respond to changes in climate, precipitation, and effects from pumping. Many of the observation wells are equipped with satellite telemetry to provide real time information on water levels.

The following summaries compare recent groundwater levels to all historical continuous daily records to determine percentile classes, with a minimum of 5 years of data. Historical monthly water level samples (before ~2004) are not included. A percentile is on a scale of 100 and indicates the percent of a distribution that is equal to or below it. For example, a groundwater level at the 10th percentile is equal to or greater than 10% of the water level values recorded on this day of the year during all previous years of data.

In general, a groundwater level value that is:

  • the highest ever measured for the day of year is considered High
  • greater than the 90th percentile is considered Much Above Normal
  • between 75th percentile and 90th percentile is considered Above Normal
  • between 25th and 75th percentiles is considered Normal
  • less than the 25 percentile is considered Below Normal
  • less than 10 percentile is considered Much Below Normal
  • the lowest ever measured for the day of year is considered Low

Wells classified as “Not Available” in this report do not have recent groundwater level data within the past 14 days or do not have sufficient data (less than 5 years continuous data).


Definition of Normal

It should be noted that describing water levels relative to “normal” steady state baselines requires historical water levels of a well to be relatively stationary and without significant trending in the short or long-term. Use of the term “normal” in reference to groundwater levels that are indicating a trending pattern should be regarded with caution, as there is no true “normal” water level for a given time of year in these scenarios. As a result, this report uses the “normal” term solely in reference to water levels between the 25th to 75th percentiles of historical data, not to imply a steady state baseline for comparison. Percentile data should be interpreted with the context of long-term data records, patterns, and trends.

Groundwater Level Conditions


Wells by Percentile Class

Current Year
Last Year
2025-07-31 2024-07-31
High (100) 1 (1.2%) 6 (7.5%)
Much Above Normal (90-100) 4 (4.9%) 4 (5%)
Above Normal (75-90) 1 (1.2%) 19 (23.8%)
Normal (25-75) 21 (25.9%) 36 (45%)
Below Normal (10-25) 6 (7.4%) 8 (10%)
Much Below Normal (0-10) 2 (2.5%) 2 (2.5%)
Low (0) 5 (6.2%) 4 (5%)
Across All Classes 40 79

Percentile Class Changes Since Last Year

This plot shows groundwater level percentile classes for each day over the past year to observe how conditions have changed over time. Using a different colour scheme than the rest of the report for visual purposes, more darker brown colours mean more wells in lower percentiles while more darker blues mean more wells in higher percentiles. Water levels in the 25-75th percentiles are in the lightest blue.

Wells Below Normal

This section reports on the percentage and number of wells below the 25th percentile for the past 14 days and one year prior for comparison. Only wells with data during the two time periods are included.

All Wells

Current Year
Last Year
2025-07-31 2024-07-31
16.1% (13/40) 17.5% (14/79)

By Aquifer Type

Aquifer Type
Current Year
Last Year
2025-07-31 2024-07-31
Confined sand and gravel 31.2% (5/16) 20% (7/35)
Crystalline bedrock 66.6% (2/3) 37.5% (3/8)
Sedimentary 37.5% (6/16) 16% (4/25)

Latest Details

Latest details on observation wells. Click on a well number in the table to find a link to a hydrograph and long-term record plot. Click on an aquifer number to find more information about the aquifer.

Well Location Aquifer Aquifer Type Latest Date Percentilea
Alberni-Clayoquot Regional District
OW329 Ucluelet 159 Unconfined sand and gravel ** 2025-07-31 Normal (42.3%)
(n = 22)
Capital Regional District
OW058 North Saanich 610 Confined sand and gravel ** 2025-07-31 Normal (46.2%)
(n = 20)
OW060 North Saanich 609 Confined sand and gravel ** 2025-07-31 Much Above Normal (92.6%)
(n = 21)
OW065 Sidney 608 Crystalline bedrock ** 2021-04-28 Not Available
(n = 19)
OW071 Saanich 616 Confined sand and gravel ** 2025-07-10 Not Available
(n = 20)
OW125 Mayne Island 620 Sedimentary ** 2025-05-13 Not Available
(n = 20)
OW128 Mayne Island 447 Sedimentary ** 2025-07-31 Normal (55.2%)
(n = 21)
OW240 North Saanich 608 Crystalline bedrock ** 2025-07-31 Below Normal (16%)
(n = 22)
OW258 Galiano Island 320 Sedimentary ** 2025-07-31 Normal (73.9%)
(n = 22)
OW265 North Saanich 608 Crystalline bedrock ** 2025-06-09 Not Available
(n = 23)
OW281 Saltspring Island 721 Sedimentary ** 2025-07-31 Normal (75%)
(n = 22)
OW283 Pender Island 711 Sedimentary ** 2025-07-31 Low (0%)
(n = 22)
OW284 Pender Island 720 Sedimentary ** 2025-05-15 Not Available
(n = 22)
OW290 Saturna Island 737 Sedimentary ** 2025-07-30 Low (0%)
(n = 20)
OW319 Saturna Island 735 Sedimentary ** 2025-07-31 Normal (41.2%)
(n = 20)
OW327 Galiano Island 320 Sedimentary ** 2025-05-13 Not Available
(n = 22)
OW338 Central Saanich 608 Crystalline bedrock ** 2025-06-09 Not Available
(n = 22)
OW343 Central Saanich 608 Crystalline bedrock ** 2025-06-09 Not Available
(n = 21)
OW372 Gowlland Tod Park 680 Crystalline bedrock ** 2025-07-10 Not Available
(n = 18)
OW373 Salt Spring Island 722 Sedimentary ** 2025-07-31 Much Below Normal (5.6%)
(n = 19)
OW438 Salt Spring Island 721 Sedimentary ** 2025-07-30 Above Normal (81.8%)
(n = 11)
OW443 Sooke 606 Crystalline bedrock ** 2025-05-20 Not Available
(n = 7)
OW469 Sooke 599 Confined sand and gravel ** 2025-07-31 Normal (57.1%)
(n = 7)
Comox Valley Regional District
OW268 Denman Island 740 Sedimentary ** 2025-07-30 Normal (29.2%)
(n = 22)
OW288 Hornby Island 438 Sedimentary ** 2025-07-31 Below Normal (13.6%)
(n = 22)
OW351 Comox 408 Unconfined sand and gravel ** 2025-06-20 Not Available
(n = 22)
OW369 Oyster R. Unconsolidated NA
** 2025-05-21 Not Available
(n = 19)
OW371 T'sable River 415 Unconfined sand and gravel ** 2025-07-31 Normal (44.4%)
(n = 19)
Cowichan Valley Regional District
OW204 Duncan 186 Unconfined sand and gravel ** 2025-06-16 Not Available
(n = 22)
OW211 Duncan 186 Unconfined sand and gravel ** 2025-06-16 Not Available
(n = 22)
OW233 Cowichan Bay 197 Confined sand and gravel ** 2025-06-16 Not Available
(n = 22)
OW320 Cobble Hill 197 Confined sand and gravel ** 2025-07-31 Below Normal (22.2%)
(n = 15)
OW345 Cobble Hill 197 Confined sand and gravel ** 2025-06-16 Not Available
(n = 22)
OW355 Chemainus 172 Unconfined sand and gravel ** 2025-07-31 Normal (35%)
(n = 21)
OW428 Cowichan 1287 Confined sand and gravel ** 2025-06-25 Not Available
(n = 12)
OW429 Cowichan 178 Confined sand and gravel ** 2025-06-25 Not Available
(n = 12)
OW430 Cowichan 198 Sedimentary 2024-09-03 Not Available
(n = 11)
OW431 Cowichan 199 Confined sand and gravel ** 2025-06-03 Not Available
(n = 12)
OW439 Cobble Hill 203 Crystalline bedrock ** 2025-07-30 Normal (42.9%)
(n = 8)
OW470 Mill Bay 206 Unconfined sand and gravel ** 2025-07-30 Normal (71.4%)
(n = 7)
OW488 Cowichan Station 197 Confined sand and gravel ** 2025-07-30 Normal (40%)
(n = 6)
OW489 Cowichan Station 197 Confined sand and gravel ** 2025-06-16 Not Available
(n = 6)
OW493 Cowichan Station 198 Sedimentary ** 2025-06-16 Not Available
(n = 5)
Mount Waddington Regional District
OW201 Alert Bay 858 Confined sand and gravel ** 2025-07-31 Low (0%)
(n = 21)
Regional District of Nanaimo
OW196 Gabriola Island 709 Sedimentary ** 2025-07-30 Normal (57.1%)
(n = 22)
OW197 Gabriola Island 709 Sedimentary ** 2025-07-31 Below Normal (10%)
(n = 22)
OW232 Lantzville 215 Confined sand and gravel ** 2025-07-31 Below Normal (24%)
(n = 22)
OW287 Coombs 220 Sedimentary ** 2025-03-25 Not Available
(n = 22)
OW295 Qualicum Beach 217 Confined sand and gravel ** 2025-07-31 Normal (54.2%)
(n = 22)
OW303 Qualicum Beach 1250 Confined sand and gravel ** 2025-05-30 Not Available
(n = 22)
OW304 Parksville 216 Confined sand and gravel ** 2025-04-16 Not Available
(n = 22)
OW310 Bowser 416 Confined sand and gravel ** 2025-07-31 Below Normal (17.4%)
(n = 22)
OW312 Cassidy 161 Unconfined sand and gravel ** 2025-04-03 Not Available
(n = 22)
OW314 Parksville 216 Confined sand and gravel ** 2025-07-31 Much Above Normal (90.9%)
(n = 22)
OW316 Gabriola Island 709 Sedimentary ** 2025-07-30 Normal (39.1%)
(n = 22)
OW321 Qualicum 1250 Confined sand and gravel ** 2025-05-30 Not Available
(n = 22)
OW337 Ladysmith 162 Sedimentary ** 2025-04-03 Not Available
(n = 21)
OW340 Lantzville 215 Confined sand and gravel ** 2025-04-11 Not Available
(n = 22)
OW385 Gabriola Island 709 Sedimentary ** 2025-07-30 Normal (71.4%)
(n = 15)
OW388 Nanaimo 211 Crystalline bedrock ** 2025-07-31 Low (0%)
(n = 15)
OW389 Qualicum Beach 664 Unconfined sand and gravel ** 2025-07-31 Normal (42.9%)
(n = 15)
OW390 Cedar 162 Sedimentary ** 2025-07-30 Much Above Normal (90.9%)
(n = 14)
OW391 Little Qualicum 662 Confined sand and gravel ** 2025-07-31 Much Below Normal (7.7%)
(n = 14)
OW392 Nanoose 1098 Confined sand and gravel ** 2025-07-31 High (100%)
(n = 14)
OW393 Nanoose 219 Confined sand and gravel ** 2025-07-31 Normal (64.3%)
(n = 14)
OW394 Nanoose 218 Sedimentary ** 2025-03-28 Not Available
(n = 13)
OW395 Nanoose 219 Confined sand and gravel ** 2025-03-28 Not Available
(n = 13)
OW396 Nanoose 219 Confined sand and gravel ** 2025-07-31 Normal (41.7%)
(n = 13)
OW397 Nanoose 1098 Confined sand and gravel ** 2025-07-31 Much Above Normal (91.7%)
(n = 13)
OW398 Parksville 216 Confined sand and gravel ** 2025-04-16 Not Available
(n = 12)
OW424 Coombs 1250 Confined sand and gravel ** 2025-07-31 Normal (27.3%)
(n = 12)
OW425 Qualicum 1251 Confined sand and gravel ** 2025-02-19 Not Available
(n = 12)
OW426 Qualicum 662 Confined sand and gravel ** 2025-02-19 Not Available
(n = 12)
OW427 Qualicum 416 Confined sand and gravel ** 2025-02-19 Not Available
(n = 12)
OW432 Yellowpoint 162 Sedimentary ** 2025-07-30 Low (0%)
(n = 12)
OW433 Qualicum 1250 Confined sand and gravel ** 2025-05-30 Not Available
(n = 12)
OW434 Qualicum 217 Confined sand and gravel ** 2025-05-30 Not Available
(n = 12)
OW435 South Wellington 165 Sedimentary ** 2025-05-24 Not Available
(n = 12)
OW436 Cassidy 160 Confined sand and gravel ** 2025-04-03 Not Available
(n = 9)
OW437 Cassidy 161 Unconfined sand and gravel ** 2025-04-03 Not Available
(n = 9)
Strathcona Regional District
OW383 Quadra Island 751 Unconfined sand and gravel ** 2025-05-21 Not Available
(n = 17)
a n is the number of years included in the percentile calculation.
** Values with a Working approval status

Historical Water Level Plots

Annual hydrographs and historical records for the observation wells summarized above can be found in this section.

Note: ‘Working’ data are preliminary and have not yet been finalized as ‘Approved’ data with approved corrections and data grades for quality assurance. Quality assurance procedures may result in differences between what is displayed as ‘Working’ and what will become the official record.

OW058OW060OW065OW071OW125OW128OW196OW197OW201OW204OW211OW232OW233OW240OW258OW265OW268OW281OW283OW284OW287OW288OW290OW295OW303OW304OW310OW312OW314OW316OW319OW320OW321OW327OW329OW337OW338OW340OW343OW345OW351OW355OW369OW371OW372OW373OW383OW385OW388OW389OW390OW391OW392OW393OW394OW395OW396OW397OW398OW424OW425OW426OW427OW428OW429OW430OW431OW432OW433OW434OW435OW436OW437OW438OW439OW443OW469OW470OW488OW489OW493

Appendices

A - Disclaimer

Warranty Disclaimer

This information is provided as a public service by the Government of British Columbia, Box 9411, Victoria, British Columbia, Canada V8W 9V1.

This website and all of the information it contains are provided “as is” without warranty of any kind, whether express or implied. All implied warranties, including, without limitation, implied warranties of merchantability, fitness for a particular purpose, and non-infringement, are hereby expressly disclaimed. Links and references to any other websites are provided for information only and listing shall not be taken as endorsement of any kind. The Government of British Columbia is not responsible for the content or reliability of the linked websites and does not endorse the content, products, services or views expressed within them.

Limitation of Liabilities

Under no circumstances will the Government of British Columbia be liable to any person or business entity for any direct, indirect, special, incidental, consequential, or other damages based on any use of this website or any other website to which this site is linked, including, without limitation, any lost profits, business interruption, or loss of programs or information, even if the Government of British Columbia has been specifically advised of the possibility of such damages.

B - Calculations

General details

  • Water year starts in October.
  • Well measurements are all in Depth Below Ground in metres.

Percentiles

  • Percentiles are calculated individually for each day of the year for each well, so only years with continuous daily data are used in calculations (no historic point samples used).
  • Recent percentiles values are calculated with all years of data, however the current year values are not considered for the percentile class hydrograph plots; and so there may be slight differences in how the most recent value’s percentile compares on the figure.
  • Minimum 5 years of data required for a percentile calculation.
  • 366th day in leap years is omitted.