GROUNDWATER-SURFACE WATER INTERACTION: AN EMERGING ISSUE IN REGULATORY DECISION-MAKING AND RESOURCE MANAGEMENT

The highly urbanized San Francisco Bay Area is affected by impacts from commercial, industrial, and residential development, including wastewater and industrial discharges, historic loss of wetlands, stream modification for flood control and urban development, and surface water and groundwater pollution by a myriad of chemicals. Expansion of residential development in the past twenty years has led to the covering of natural recharge areas, greater storm water runoff, and alteration of stream channels and riparian zones. At the same time, water quality in rural areas is threatened by over-grazing, excess agricultural fertilizer and pesticides use, confined animal facilities, and expansion of sewage and septic systems.

Historically, regulatory and resource agencies have dealt with these issues through separate groundwater and surface water programs. This compartmentalized approach often lacks communication and coordination, which can lead to management of one resource at the expense of the other. Increased awareness of groundwater and surface water interactions will lead to improved water quality in the Bay Region. Integration of both programs is especially important as solutions are sought for better storm water management and attainment of total maximum daily loads (TMDLs).

The Water Board's Groundwater Committee formed the Groundwater-Surface Water Interaction Workgroup to facilitate better integration of groundwater and surface water programs. The Workgroup's mission is to preserve, enhance, and restore water quality through a comprehensive understanding of the hydrologic cycle, focusing mainly on collaborative engagement between surface water and groundwater staff, facilitating an increased knowledge of surface water and groundwater interaction.

The Workgroup's goals include (1) evaluate existing scientific knowledge,and identify and fill gaps in our agency's understanding of groundwater/surface water interaction, in order to develop eventual guidance; (2) develop a long-term, integrated management approach, based on systematic, scientific assessment; and (3) create blueprints for action (fact sheets). We expect some of our recommendations to be evaluated for integration into the Water Board's planning document (Basin Plan) and fact sheets to become part of our educational outreach.