The raw water at the uShaka intake is only filtered through about 3m of sand. After rains like we have just had, and especially after easterly winds, the water from the Mgeni travels down the coast and can get as far as the uShaka intake. If there is a westerly blowing you get the water from the Umbilo, Mhlatuzana and Manzimyana Rivers flowing through the harbour and moving into the Vetch's area. Short story is that the water quality varies and is (relatively) worse after heavy rains. However the ammonia levels are still low, as are the nitrates and nitrites. I have had some sea water samples tested by a certified laboratory and will post the results when I have them.