 Between 2002 and 2006, during the renaturalisation works, 14 retention reservoirs of great size were built, but investments ranging between 2 and 6 million dollars will still be required to alleviate the problem, in part blamed on old constructions where the gutters are directly connected to the city's sanitary installations.Since 1979, the non-profit oriented organisation "Fishing in town" releases brook trout young into the river in order to facilitate its access to fishermen, specially young fishers.In 2008, 25 000 trouts were planted, for a sum of 700 000 since the organisation's foundation.