Field notes taken on Mallet Creek in August are in and are beginning to give a picture of how the creek and ecosystem may have managed over the dry, hot summer.
A statistical analysis of the data points has yet to be run on the Gabriola Island creek – that will be released in Spring 2022 – along with the other waterways that are part of the Regional District of Nanaimo’s community watershed monitoring network. Gabriola Streamkeepers collects readings on temperature, dissolved oxygen, conductivity and turbidity on the creek and submits it to the RDN.
Julie Pisani, the RDN’s drinking water and watershed protection program coordinator, said summer water temperatures at the creek are “right on average” with previous years, at 15 degrees Celsius, which is below the 17-degree guideline for coho rearing.
Pisani said they think the creek’s steady temperature through the heat wave is attributable to cool groundwater contributions.
Mallet Creek “fared better than the Millstone River and other rivers on Vancouver Island that don’t have as much groundwater influence,” Pisani said.
Dissolved oxygen was lower this year, which could be reflective of lower flow. Turbidity was higher than previous years though nothing within concern or close to what is seen during winter storms. Pisani said at this point they aren’t sure what to attribute the turbidity change to but are considering whether it is related to a dam upstream.
The early data reinforces to Pisani how important groundwater is to the health of many waterways – “and particularly small creeks on Gabriola” – to keep them flowing through drought and within range during heat waves.
Rachelle Stein-Wotten, Local Journalism Initiative Reporter, Gabriola Sounder