Foreword

This book introduces how groundwater and surface water features such as rivers, streams, lakes and wetlands are linked and function as a continuous hydrologic system. Groundwater systems underpin these terrestrial surface waters. Surface water and groundwater are continuously linked in the hydrological cycle but often are assessed separately even when it is recognized that water exchanges occur between them. Conceptually, surface waters and the associated shallow groundwater systems are best viewed as a single interacting system, a continuum that is one water resource. Investigations reveal that water enters and leaves surface water features and the groundwater zone at multiple rates, locations, scales and time frames. This exchange physically moves both water and dissolved constituents between groundwater and surface waters and supports associated groundwater dependent ecological communities. Those who understand the conceptual and field linkages will be able to determine how natural and impacted streams, lakes and wetlands function, and which preservation or restoration actions can resolve issues and meet goals.

Some examples include: what information is needed to plan and execute remediation efforts if stream, lake and wetland features become impacted from physical and chemical alterations? In river systems, what level of river water exchange with the bed, banks and floodplain is required to support a natural geomorphic set of conditions, and appropriate aquatic and terrestrial ecological systems? If a groundwater contaminant is migrating towards a group of lakes, which ones are likely to be impacted and at what locations? When lakes act both as groundwater discharge sites and sources of groundwater recharge, how can specific aquatic ecosystems be maintained? How can vegetated areas associated with spring wetlands be restored? When water is pumped from groundwater near a lake, will be the amount of lake water available for irrigation diversions be impacted? Though these questions are not answered specifically in this book, the book builds the necessary foundation upon which to understand the issues and formulate resolutions. This book presents the conceptual models, descriptions of field-based methodologies, and modeling tools needed to understand surface-groundwater exchanges at multiple scales and in varied hydrogeological conditions.

This book has been prepared by a senior groundwater scientist who has pioneered research concerning groundwater-surface water interactions and taught a course on the subject for 30 years as well as a range of introductory and advanced hydrogeology classes at the university level. He is a specialist in field investigations, groundwater problem analysis, modeling building and computer simulation.

John Cherry, The Groundwater Project Leader
Guelph, Ontario, Canada, September 2020