Valuation of land use and management impacts
on water resources in the Lajeado São José micro-watershed

   Reduction of suspended sediment in surface water due to a change in agricultural practices

   63.5 square kilometers

   upstream: farmers
   downstream: water supply utility

   Avoided cost method (reduction of water treatment costs)

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As a cause of improper land use and management and inadequate disposal of organic manure in agricultural watersheds, erosion processes are increased, which have on-site impacts like soil impoverishment and gradual decrease in crop yields, loss of biodiversity and reducing farmers income. Off-site impacts are related to river sedimentation, lost of water storage capacity, flood hazards, reducing water quality, increasing in water treatment cost and damage to aquatic life.
The present case study describes off site benefits of changed land management practices, including zero and minimum tillage, contour-tillage, crop rotation, cover crops, green and organic manure, level terracing and forestation, in a watershed area in terms of water quality and reduction in water treatment costs. As a consequence of better management practices, the suspended sediment concentration in river dropped 69 percent and the savings in water treatment cost for domestic supply, was 2 445 US$ per month.
On-site benefits such as: Reduction in soil erosion; increase in crop productivity; improvement in physical, chemical and biological soil conditions; increasing farms income and leading to better quality of life, are also mentioned.
Important lessons, related to technical strategy, participatory methodology, research and extension service , monitoring system and externalities could be learned, which are of significant relevance for management projects in micro-watersheds.