A few items here.
Toronto just approved additional litter pick-up services in heavily used downtown parks, much needed and overdue.
Second there are steps one can take to address algae growth. The link that follows is not meant for large public works, but it absolutely can be done w/them.
Notably, using an additive to the water.
http://homeguides.sfgate.com/prevent-algae-garden-fountains-41269.html
Third, misuse of the park, on a limited basis can be unavoidable. Where it is a substantial problem (and not a design flaw, ie. no garbage bins/full bins) then one should lobby to have by-law enforcement spend a week there and make the City a bundle of cash. Ticket everyone who litters, doesn't pick up after a dog or willfully damages public property.
In terms for repairing the fountain, if the issue is unrelated to the water-works, then that may be a design issue or a by-law enforcement issue. If its related to the water-works then it may be a design issue, but there is also a long-standing problem that Parks tends to use in-house plumbers of which there are an acute shortage, so repairs may take several days to get to. That's not really acceptable.
It resulted in a public washroom in a park near me, not being open by mid-May, even though its supposed to be open May 1st.
There is also a long-standing issue of the schedule for seasonal staff; that doesn't affect what's going on now, but they generally work May 1st to Thanksgiving or Oct 31 in Parks.
In order to have Parks up to snuff for May 1, seasonal staff need to be hired by April 15 at the latest, and should really be scheduled to do pro-active maintenance until Nov 15th each year.
There is also a need not to create work through bad design. (washrooms that aren't heated at all, not only have their water shut down, but fixtures (faucets etc.) removed for winter.)
Maintaining low-level in-floor heating and insulating the pipes would be a better choice in my judgement, even if the washroom is closed. Better still, keep most of them open year round.