Author(s)

R. G. Quimpo

Abstract

Prior to the implementation of an infrastructure project, an environmental impact assessment is necessary to secure the acceptance of stakeholders and the approval of various regulating agencies. Since the project has not yet been constructed, the projected impacts are based on surveys and modeling studies that need to be verified during and after construction. In projects which impact the water resources of a region, planners and designers use hydrologic models to predict future conditions on water quantity and quality. This paper will focus on the hydrologic modeling, instrumentation and monitoring requirements using as case study the design and construction of a stretch of the Interstate system of highways in the United States. The highway segment traverses agricultural, forest and game lands resulting in the alteration of landscapes and changes in watershed delineations. In some sections of the project, the highway cross-section includes an infiltration gallery constructed under the roadway which permits groundwater flow from headwater areas to bypass the construction corridor. The behavior of the altered watersheds needs to be examined to determine if they conform reasonably with projected performance. Aspects of the study related to runoff modeling and prediction, storm water sediment and erosion practices, wetland and stream restoration were investigated. The logistics of instrumentation, monitoring, data-acquisition and analyses are discussed. The findings will form the basis for developing guidelines for use by the implementing agency in future projects. Keywords: hydrologic models, hydrologic monitoring, erosion and sedimentation, environmental impact, infiltration gallery, stream restoration, watersheds, wetlands, BMP, watersheds.

Keywords

hydrologic models, hydrologic monitoring, erosion and sedimentation, environmental impact, infiltration gallery, stream restoration, watersheds, wetlands, BMP, watersheds.