Howdy,

When bioretention systems receive a constant baseflow, they often grow algae around the inlet. This is well understood. It's a problem because the algae can block the filter media (at least the part that its growing on) and cause water to pond on the surface. Today however, we have a site growing algae for a different reason... I think. It's the first time I have seen it happen for this reason.

Cheers

Jack