What happens when a storm water channel is unmaintained?
Water has to move. There are only two ways it can do that - through a pipe or over the natural ground. If it moves over natural ground, it’s likely going to create marshy areas where aquatic and riparian plants will grow. These plants are good - they help slow the water as it moves downstream and this prevents the water from picking up the soil on its way downstream. These aquatic/marsh plants also help filter the water as it moves - the roots uptake the water, removing harmful chemicals and nutrients and the plants also act as a mechanical filter by trapping sediment before it moves downstream.