SSI, NORTH Watersheds
Walkers Brook(WLBK) Watershed "Notes"
- Walkers Hook area -
LAST UPDATE 2024/02/05
SSI North Area - overview watersheds (colour coded, CRD, 2018) & watershed note areas
North Island, Walkers Brook Watershed
From our ongoing North Island, freshwater cataloguing - notes on the Walkers Brook watershed area. Cf. the SSI FWC webmap for field locations and charted information (where available).
The content of these "Notes" entries is dependant on the information that is currently available, from FWC volunteer work, FWC reporting or from other sources. A big thank you to our volunteers.
Note - if you have additional insights into this area (the watershed, it's creeks or wetlands), can help with site(s) access, or are interested in being involved in data collection for this project area, please contact the SSIFWC Project Lead.
General Watershed & FWC Creek(s) Information:
For now these notes draw heavily extracts from our monthly FWC "Which Creek Is It" Competition, from our Salt Spring Island FreshWater Catalogue Watershed Stewardship Group Facebook page, with "field note" addendums where additional information has become available. Additional volunteer resources will enable us to do more!
The data collected from our FWC field work in the Walkers Brook watershed gathers seasonal flow and chemistry baseline data, investigating watershed surface water and groundwater baseflow(?) discharge to the sea - a key component to any planned watershed, or water budget, and input to validating groundwater recharge potential models. In an area with potential saline intrusion risks additional "flow balance/change" information for this watershed may be of value.
The principle (only?) creek and sea-outfall from the Walker Brook (WLBK) Watershed is Walker Brook creek, with an outflow adjacent to the Walkers Hook tombola. Walkers Brook Creek was a March 2019, Which Creek Is It competition entry.
North Island WLBK watershed context and WLBK watershed detail (Lidar backdrops), Walkers Brook creek images
The Walker Brook Watershed:
Is 125.7 hectares (310.6 acres) in size
Receives something like 119,415,000 litres (26,267,628 gallons) of rainfall (precipitation or surface water) per annum (water volumes are approximate with no consideration of surface/terrain conditions, nor rainfall variability within the catchment area)
Appears to only have one creek outfall to the sea (so is a great location for watershed freshwater flux-to-sea flow measurements)
The Walkers Brook creek remains an SSIFWC creek of interest in the north of the island, it appears to flow year round, one of the few in this north island area. We have active FWC volunteer data collection ongoing in the watershed, cf our SSI FWC webmap for location details.
Historical & Other Watershed Insights:
TBD.
Note - any other local insights, or interested in contributing to the historical/other notes on our islands' watersheds, please contact the SSIFWC Project Lead.
FWC "Citizen Science" & Other Watershed Notes - Reporting:
The Walkers Brook creek field site at the coastal outfall is influenced by tides and seawater invasion.... This tidal influence is likely to be a combination of the visible surface creek inflow at higher tides, and subsurface seawater infiltration effects (during the diurnal tidal cycle), a known coastal phenomenon (at surface and in the subsurface) at several island locations. Both of these tidal controls negatively impact creek water chemistry at the outfall and potentially modify creek flow rates.
An inland Walkers Creek site (closish) to the coast gives access to suitable freshwater flow and chemistry sampling. Here we are developing a WLBK watershed freshwater baseline dataset, to glean insights into groundwater recharge potential and perhaps a water budget/balance for this area?
The influence of tidal variations in coastal watersheds and local, coastal water tables and potential seawater infiltration into groundwater aquifers, is known for parts of the island, particularly the north (eg the watersheds WLBK, 1983). This Klassen & Allen (2016) paper is useful to understand the areas' saline intrusion risks, and our FWC chemistry results in these areas. If interested in the saline intrusion story have a look at some of the Freshwater and Island models illustrations, and/or read Klassen & Allen.
Side note - a similar seawater invasion into coastal creeks (and aquifers...) phenomena is seen at another northern "1983" watershed FWC site in the "Jack Foster forest trail beach outfall” creek to the NW (cf SSI FWC webmap for locations). Here low conductivity readings (conductivity 2.06, Ph 7.86) may be an indicator of pristine or background creek conditions (Environment Canada).
FWC Project Data Collection - Summary
Our Walkers Brook watershed area field site was initially at a compromised (tidally influenced) site, and is now inland in a relatively downstream watershed location. We have some 5 years of reconnaissance and weekly/monthly, FWC flow and chemistry field data (NB adjacent graphs not up-to-date).
Seasonal variability in conductivity in the creek are an an indicator of pristine or background creek conditions at this creek site. Significant variability within conducitivities year-round suggest an additional control on creek water salinity, possibly relating to natural salt springs within the watershed area?
Overall low water temperatures (showing a subtle inverse relationship with air temperature?) may indicate a possible shallower(?) groundwater component to streamflow. However, no flow during summer suggests any groundwater base flow is intermittent and may be (seasonally) water table dependant...
FWC images and videos:
Walkers Brook watershed images. Note - all FreshWater Catalogue images & videos copywrite belongs with the WPS and the FWC. We are grateful for due acknowledgement of copywrite in any use or publication of these educational resources.
Other Local Area Resources:
Manley, D., & Stewardson, M., 2014., Salt Spring Island Riparian Areas Regulation Mapping Project. Mainstream Biological Consulting, sponsored by IT.
Klassen, J. & Allen, D. M. 2016., Risk of Saltwater Intrusion in Coastal Bedrock Aquifers: Gulf Islands, BC