Author: Matt James, PRGI President (Acting) and Lake Sub-committee leader
There is understandably a lot of local interest regarding the situation with the lake, and I thought I’d take this opportunity to give you an update of my ongoing discussions with the various stakeholders. It should be read in conjunction with the previous report and updates shared.
Public Health Warning: On 30th Nov 2020 - Canterbury DHB issued notification of the lake being closed to all recreational users because of toxic algae. This remains the current situation with the water quality being monitored weekly.
Other affected areas: Since this notice being issued for Pegasus, similar notices have been posted for Lake Forsyth, Lake Ellesmere, East Kaiapoi Lake, Lake Rotorua, Hurunui River, Ashley River, Waiau River, and Selwyn River.
Current maintenance at Pegasus Lake: Prior to Christmas, the Lake owners (Templeton) engaged contractors to undertake the required maintenance programme around the lake surround and to remove weed from the lake itself. This work is ongoing, and divers are due to be deployed to review and address water flows around key lake areas, including the waterfall.
The lake maintenance programme is being currently reviewed, with a report due back late February.
The Lake has 2 purposes:
As a utility – The lake captures stormwater run-off, minimising the risk of local flooding, and
As a recreational asset – To become a venue for public use and enjoyment.
The needs of both purposes have to be balanced in any future changes in the lake management plan (and its associated financial impacts).
A key area to be tackled in any solution is the impact of the quality of water entering the lake and how the lake can naturally process it, i.e. bloom contaminates can be “imported” and then flourish in poor lake conditions. The lake depth and rate of water flow has a significant impact on how contaminants can be adequately, naturally processed without the use of supplementary technology.
The experts are now undertaking further detailed review of the potential solutions, with the aim of an updated report being available for Templeton (the lake owner) for the end of February.
The process of reviewing and deciding the next steps will need to involve the ongoing stakeholders as well as Templeton, as anything Templeton deploy will ultimately be vested to WDC with ECan oversight for water quality monitoring.
A key consideration is obviously cost. This needs to include ongoing running and maintenance costs, in addition to the initial purchase and installation costs of any equipment.
Other considerations will be potential environmental impacts to the neighbouring residents within the community, as well as the surrounding wetlands and its delicate ecosystem.
Sadly, bloom is an issue nationwide.
The man-made lake was always going to mature with age, with the task of managing the water quality made harder.
All the parties remain actively committed to improving the lake situation; both currently and in the longer-term.
Long-term solutions are being robustly progressed, with all appropriate due diligence being undertaken by the parties.
The management of the weeds should help the current situation.
Unfortunately, there is no quick fix available.
I’ll keep you informed as key news comes in.