Water Assessment Tool for Evaluating Risk (WATER).

The Water Assessment Tool for Evaluating Risk (WATER) is a pollution risk assessment tool developed for use in the field by the Pacific Islands Area Natural Resources Conservation Service (NRCS) employees and others developing conservation and nutrient management farm plans.  The tool was developed in Microsoft Access®.  WATER is based on several previous tools developed by the University of Hawaii—College of Tropical Agriculture and Human Resources (UH-CTAHR) and NRCS from 2003 to present. The tool contains five main components: 1) A pre-screening water risk assessment based on soil, geographic and climate data, which provides a simple assessment for the potential leachate to leave the root zone and for runoff to leave the edge of a field; 2) A transport component based on NRCS Technical Release 55 (TR55) runoff curve numbers (CN) for hydrologic soil groups, the Revised Universal Soil Loss Equation (RUSLE) data, and local conditions.  This transport component provides data input to the following two components; 3) A phosphorus (P) risk component based on soil phosphorus concentrations and transport potential and 4) a nitrogen (N) risk component that calculates a simple nitrogen balance of soil nitrate-N with estimated plant N uptake and determines risk based on soil N concentration and the soil leaching and runoff potential. The tool also includes 5) A fertilizer input component that balance nutrients with recommended nutrient quantities and assists NRCS conservationists with completing the nutrient management job sheets for farmers to implement nutrient management according to NRCS standards and specifications.  An output report in laymen's terms accompanies each component described previously.  WATER is a management tool that will ease the complexity of the decision making process for conservationists and land managers with regards to pollution risks from farming.