Janet Timmerman, Information Officer for the Center for Rural and Regional Studies will be speaking to three environmental science classes at Marshall High School on Wed. March 5th. Based on several of the Center's publications, Timmerman's topic " Draining the Great Oasis: A Lesson in Sustainability" will cover the history of land and water use in the area. The sessions will use a hands-on case study to bring students to a greater understanding of human impact on land and water resources.