An integrated approach for modelling and managing golf course water quality and ecosystem diversity

Abstract

Models can help planners assess the potential impacts of planned land development. However, pollutant yield results from common watershed water quality models are inadequate and must be coupled with other important ecosystem component models to assess the overall impact of land development and management. For example, golf course development typically replaces agricultural or native lands with intensively managed grassland with potential impacts on water quality, as well as avian and aquatic species habitat. An integrated modelling concept was demonstrated using readily available models and data for a hypothetical golf course within the Little Kitten Creek Watershed near Manhattan, KS, USA. A watershed water quality model (EUTROMOD) combined with local fish habitation data and habitat suitability index modelling was used to simulate the overall ecosystem impact of projected golf course design and management actions. Models were calibrated using data for grass and native prairie conditions, and future scenarios were simulated to guide design and management actions. Compared with the native conditions, good golf course management was simulated to increase annual nitrogen (N) yield by 148% and phospohorus (P) yield by 24% with little impact on runoff or erosion, while a poor management scenario increased the N yield by 380%. This change in aquatic nutrient levels along with concurrent projected changes in stream habitat led to a potential impact on three of four fish species analyzed. Avain habitat was also impacted depending upon design and management of non-playing area. An overall design and management plan was developed with the goal of maintaining predevelopment levels of water quality and habitat. Sustainable water quality management must include proper soil and water conservation, irrigation scheduling, and fertilizer and pesticide management. Appropriate features must be designed into numerous contiguous area (1.2 ha minimum for grassland and 0.8 ha minimum for woodland) of non-playing area (rough, riparian area, etc.) to meet avian habitat needs. And a diversity of stream habitat conditions must be maintained, including clear pool and gravel-substrate riffle zones, and permanent and intermittent streams. This integrated modelling approach demonstrated the utility of a simplistic framework for analyzing and assessing ecosystem impacts of land development. Further work should integrate and test more complex models and interrelationships between models for lands undergoing a variety of ecosystem changes.