This is the result of one of their countless project mis-management fiascos.
A few years ago, the council budgeted about $640K to drain the lake and dredge out the huge amount of silt that had built up over many years. The silt was so thick that it meant the lake had become quite shallow and thus was subject to massive amounts of weed -- which decomposes over summer to produce a nasty putrid smell.
Well after blowing the budget by 100% ($1.2m) they still hadn't dredged the lake so they simply refilled it, put some el-cheapo exercise equipment around its shores (to appease the locals) and said "job done".
As a result, at the end of a not-so-hot summer, the still very shallow water has warmed to the point where oxygen levels have dropped and nasty bacteria are once again flourishing.
Since this fiasco we've had $1m of public swallowed up by the Putararu Timber Museum (because the SWDC attached strings that included all sorts of "reports" and "studies" that consumed most of the $1m); a vehicle compound that took 4 months longer than planned to complete because they (apparently) couldn't get a gate with card-swipe system for it; a CCTV camera system for the CBD that was supposed to be completed over 6 months ago but remains incomplete to this day; a rail siding that went 250K over budget because the clever engineers forgot about stormwater drainage and lighting until after it was built (this was also supposed to create 36 jobs but has so far created less than a quarter of that); a fence around a pile of dirt that saw contractors sitting around on site for half a day waiting for the plans to arrive; and next -- a $2.5m redevelopment of the front of Tokoroa's CBD in the lunatic belief that it will encourage people to stop and buy fridges, washing machines and TV sets as they drive past on SH1.
When there is no accountability for bad performance, bad performance becomes endemic.
And thus it is with the SWDC.