Figure 3: Proportional sediment contributions (%) by land use for tributaries and main reaches at confluences of the Waitangi River Catchment, Northland (2014). The results show a progressive shift from soil erosion sources in the upper catchment to river-bank erosion in the lower catchment. Major land use sources of sediment are soils eroded from pastoral agriculture. These estimates are based on CSSI analysis of recent sediment deposits sampled from the river bed and/or banks. [Source: Northland Regional Council funded study of contemporary sediment sources in the Waitangi River catchment.]