As a result, Matthews Lagoon now receives agricultural outputs from surrounding farms; it is affected by water pollution and invasive plant species.
Boggy Pond is cut off from Lake Wairarapa and surrounding wetlands by a road and stopbank, leaving a more stable water level compared to its original state. To analyse the water and nutrient balance in these two wetlands, factors such as surface flows, surface water levels, groundwater levels, rainfall, climate data, and water quality were assessed at various monitoring stations in this study. It is believed that Matthews Lagoon and Boggy Pond have completely different water regimes. Matthews Lagoon receives surface inflow from the Te Hopai drainage scheme and discharges to Oporua floodway, but Boggy Pond only has rainfall as the water input.
The results from the water balance analysis seem to support this assumption. An unexpected finding in Matthews Lagoon suggests that water might bypass the main wetland, creating a shortcut between the inlet and outlet. As a result, the nutrient removal ability was considerably weakened by this bypass because of the short water retention time.
In Boggy Pond, there may be an unknown water input which could adversely affect the