L-THIA estimates changes in recharge, runoff, and nonpoint source pollution resulting from past or proposed development. It estimates long-term average annual runoff for land use and soil combinations, based on community-specific long-term climate data. In the basic model, the only inputs are: location (state and…
This calculator compares the annual energy performance of a building with a green roof to the same building with either a conventional dark roof or a highly-reflective white roof. The results are based on simulations run for new construction (ASHRAE 90.1-2004) apartment or office buildings and use typical weather data…
This tool estimates the greenhouse gas (GHG) emission and energy benefits associated with increasing the recycled content of materials purchased or manufactured. The tool compares baseline recycled content for common materials – including glass, wood, metals, plastics, paper, PVC, and fiberboard – to an alternate…
This Excel-based calculator was developed to help residents of Washington State size and test scenarios for rain water harvesting systems based on the typical climate. The calculator assumes that water is harvested entirely from roofs and that 80% of precipitation falling on roofs is captured. Inputs are the nearest…
The SPAW (Soil-Plant-Air-Water) model simulates the daily hydrologic water budgets of agricultural landscapes with two connected modules, one for farm fields and one for impoundments such as wetland ponds, lagoons or reservoirs. The model was developed to understand and predict agricultural hydrology and its…