How Much Rain is Enough?


We’ve had quite a bit of rain in Elphinstone in early July, which is great for our forests and gardens, but when it comes to our drinking water supply, what matters is how much rain falls in the mountains around Chapman Lake. I’ve been following this regularly via the Tetrahedron weather station, but I wanted to know how much rain is enough to refill the lake so I asked our General Manager of Infrastructure Services, Remko Rosenboom.

He told me that there’s not a simple answer to that question. There are a bunch of considerations including how dry the soil is in the area surrounding the lake, and the level of the lake.

If we have drawn the lake down 3 metres, it takes about 200 mm of rain spread out over five or more days to replenish the lake. If the lake has been drawn down even further (using the siphon system), more rain is needed.

In the second week of July we received (by my rough calculations) over 100 mm of rain up in the Tetrahedron and it refilled the lake, which was only partially drawn down. This is great news, but we still have a long summer to get through.

So, two messages. First, THANK YOU from the board of the SCRD to all Sunshine Coast residents for your efforts in conserving water. We met our daily water usage targets for the first two weeks of July. If we can continue to meet those targets through the summer, we can avoid going to Stage 4 water restrictions.

Thus the second message is, don’t stop conserving! There’s a lot of summer left. You can find a weekly water updates at the SCRD’s site.

Crisis Declaration

This is the final text of the declaration passed by the SCRD board on July 3, 2019. I made the initial motion and used the word “emergency”, but I went along with staff’s proposal to change it to “crisis” since it was clear that some residents were confused about the difference between an “emergency” (a crisis that calls for immediate action) and a “state of emergency” (a legal declaration that gives a government special powers to deal with a crisis). We don’t have any super powers at present; we’ll just have to muddle along with plain old everyday powers.

WHEREAS the SCRD has insufficient water supply available in the Chapman System to get through a dry summer without going past Stage 2 water regulations;

AND there is no prospect of bringing additional water supplies online in 2019;

AND going to Stage 4 water regulations in three of the four past summers has caused hardship to the community;

AND the 2019 spring was drier than normal and the weather forecast for the summer of 2019 is warmer and drier than normal;

AND the Tetrahedron snow pack level at the end of the winter was well below average;

THEREFORE BE IT RESOLVED that the SCRD declare an immediate Water Crisis;

AND BE IT FURTHER RESOLVED THAT the SCRD take strong measures to reduce our own water usage this summer, proactively work with large water users to implement conservation measures, and step up enforcement of water restriction violations, including mandatory fines for residents who have previously received a warning;

AND BE IT FURTHER RESOLVED THAT to address our long- term water supply situation a Water Summit of community stakeholders be convened early 2020 to make recommendations on revisions to the Drought Management Plan and Comprehensive Regional Water Plan.

Posted by Donna