Rivers have been vitally important to human populations worldwide for millennia as “highways” for inland travel, and as sources of water for drinking, cooking, cleaning, manufacturing, irrigation, and power generation, as well as repositories for human, animal, and industrial wastes. This accessible textbook takes a broad approach to river ecology, covering the basics but going beyond by including topics that are often overlooked such as blackwater streams and rivers, tidal creek ecosystems, and reservoir limnology. Since most running water (lotic) systems have been altered or impacted by human activities, there is significant emphasis on anthropogenic impacts, including sedimentation, nutrient pollution and related eutrophication issues as well as the effects of dams and river fragmentation, power plant operations, chemical contamination, wastewater treatment discharges, industrial scale livestock production, invasive species, and rural and urban storm water runoff on river ecosystems. Advances in stream and river restoration are also discussed.