The recent case of a man who released three stingrays into Lower Seletar Reservoir serves as a wake-up call (Man fined for releasing stingrays into reservoir; Sept 27).

This incident shows how easy it is to inflict damage to our water resources.

It took a civic-minded citizen to alert the authorities so action could be taken.

A recent experience I had at MacRitchie Reservoir also shows that there are lapses in the surveillance of our reservoirs.

I came across fishing enthusiasts fishing in front of the zig-zag bridge, a non-designated fishing spot, and there were no rangers in sight.

As I walked towards the multi-storey carpark, I saw more such enthusiasts unloading their gear.

It is not easy for rangers to be on watch at the reservoir at all times, but it would be useful if the rangers on duty are easily accessible through various contact points on the premises.

This should be coupled with a prominent display of contact numbers, in the event the rangers' attention is needed by the public.

It is time to step up measures to ensure our important water sources are protected.

Clara Ng Wai Soon (Ms)