As you all know, the lake is the centerpiece attraction at City Quay. The years have not been kind to the fountains, water quality and ecosystem. The board is committed to improving the lake with new fountains, plants and fish. Our vision is that the lake will be the best it’s ever been and be the envy of everyone else. Below is a review of lakes current state and our plans to improve it.
Water level and supply
Amazingly, we have our own water supply! For some reason it was only rediscovered two years ago, but the site has its own borehole. The water quality from this has already been tested. One consultant considered that it was rich in nutrients, so it is important to take care in filling the lake without some measures in place to prevent algae growth. Another consultant commented that the quality was better than tap water.
The lake has an inlet control which for some years had been used to automatically top up the water level, without knowing the source. Once the source was discovered to be our own borehole, the water authority put in a meter and issued a certificate for a very restrictive usage allowance.
We are now in the process of negotiating a significant increase in this allowance in order that much more new water can be fed into the lake throughout the year.
There are other opportunities. With our own water supply and a simple but effective filtration system we would be able to have our own emergency consumable supply if ever needed.
Algae and Water Quality
The presence of algae has been very high this year. Worldwide reports are that UV levels (which encourage algae growth) emitted by the sun have increased significantly.
Previous attempts to improve the water had included taking out the fish, preventing new water entering the lake other than rainwater and by placing plastic netting around the lake to restrict access by wildfowl. Although these practices resulted in some success in the clarity of water, it was offset by the overall negative aesthetic impacts from the low water line and plastic netting.
Also, the low water line meant that the expensive black lining of the lake was in danger of being rapidly corroded by the UV light as it became exposed to the sun, which would have considerably reduced its life resulting in very high costs in future years.
For that reason the lake was refilled. A water additive has also been used which is known to be harmless to people, plants, birds and fish, but which significantly reduces the growth of algae. This is a UV filter, which does also make the water look darker, as it is likened to adding sunglasses to the lake. For interest, this is the same solution that is used in the waters of Albert Dock.
The next step in a longer term solution is to submerge barley straw, which is a known remedy for absorbing algae from water. This will be enclosed in netted bales and should not be visible other than small pieces of straw which may sometimes escape.
Several efforts have been made over the past few years to introduce plants into the lake, at high cost with no success. We are continuing to obtain advice to see how this situation can be improved at a sensible cost, with the current intention of introducing some plants in the spring of next year.
Many people expressed their disappointment after the beautiful koi carp were removed. The explanation had been that the fish were detrimental to the quality of water in the lake. However it would be difficult to show that there had been a resulting discernable improvement to the quality of water from this action.
Another effect has been the significant increase in midges around the lake, as the larvae was no longer being eaten. This in turn has encouraged an increase in the number of spiders around the lake which have proved to be a real challenge for the cleaners as they appear seasonally around windows and doors.
The intention is now to re-introduce some fish into the lake for next year and we are seeking advice on the timing and species best suited for our needs.
Just for info, although it may seem that a goal should be to have crystal clear water, our advisor has pointed out that this wouldn’t result in the best habitat for fish, as they would have nowhere to hide and would live in a constant state of fear from birds and other predators.
The single fountain that we now have is somewhat less impressive than the four fountains that we used to have. We will be looking at alternatives to improve our water features over the coming year at a sensible cost, perhaps taking into account the impact of spray on adjacent apartments caused by excessively high jets and strong winds.