Clean Streams was contacted by an Auckland nursery due to the poor water quality of the ponds located on their site. The native plant nursery uses the ponds to provide water to all of the plants and the poor water quality is affecting this system.
To establish the cause of the poor water quality a site assessment was undertaken. Examination of the environmental parameters was undertaken, to identify the cause of the poor water quality. Significant focus was placed on the hydrology and vegetation of the site. The pond demonstrated textbook eutrophication with poor shading and increased sediment suspension. The hydrology of the site presented a closed system where water was extracted from the pond and then filtered through the site back into the pond bringing with it additional nutrients and sediment.
To address this issues Clean Streams designed a new drainage system that would not only focus on the movement of the water but also extract some of the nutrients and sediment before entering the pond. Recommendation to implement both a wetland and a floating island to aid with nutrient and sediment extraction was also suggested.