Soil erosion research in New Zealand has focused on the on-site costs of soil loss in the form of production loss and storm damage. Subsidization and implementation of soil conservation measures have primarily been justified through maintenance or improvement of farm productivity levels. The shift in responsibility for soil conservation management and damage remedies from national to regional government has highlighted public good issues raised by soil erosion. This paper develops an inventory and assessment of the relative magnitude of the impacts of soil erosion and sedimentation in New Zealand. It also provides an estimate of the total economic costs of these impacts based on the limited data available. The impacts of greatest economic significance are highlighted, as are impacts that may be significant but for which data is limited. The implications for current and potential policy strategies are briefly discussed. The approach demonstrates the degree to which policy in this area is based on incomplete information. The nature and scale of the costs involved have implications for the relative efficiency of regional rather than national approaches to addressing this issue.