Water Everywhere

Water Everywhere. Water Seeks Its Own Level. Water in Alviso is a complex issue that touches on the environment, economics, and life safety. Already susceptible to flooding, Alviso’s situation was worsened by regional development. Hard paving, which prevented water absorption into the ground, and increased groundwater pumping caused the water table to drop. As a result, the land subsided, and Alviso dropped 13 feet over the last 100 years. Situated below sea level, it became even more vulnerable to flooding., More recently, Alviso also experienced the extreme of no water. Suburban and industrial growth and salt pond construction silted in or closed off much of Alviso’s waterways. This drastically altered the amount of water that naturally flushed this wetland area, endangering the region’s environmental health., The re-channeling of the Guadalupe River and the outflow from the nearby sewage treatment plant have also impacted the level, flow, and quality of water in Alviso., [Text of Timeline Aerial Photos:] , Development has changed the Alviso area in the fifty-year span of the photographs above. Salt ponds, development, and the resulting siltation have filled in the shoreline and blocked many waterways. To aid flood control, the course of the Guadalupe River has been straightened and channelized., Aerial photo Above: Courtesy of Pacific Aerial Survey.