PUB00070

• Year: 1998
• Title: Ground Water and Surface Water A Single Resource U.S. Geological Survey Circular 1139
• CWCB Section: Interstate & Federal
• Author: T.C. Winter, J.W. Harvey, O.L. Franke, W.M. Alley
• Description: Overview of current understandimg of interaction of ground water and surface water in terms of quality and quantity
• Publications - Doc Type: Historical

PREFACE

.

Understanding the interaction of ground
water and surface water is essential to water
managers and water scientists, Management
of one component of the hydrologic system,
such as a stream or an aquifer, commonly is
only partly effective because each hydrologic
component is in continuing interaction with
other components, The following are a few
examples of common water-resource issues
where understanding the interconnections
of ground water and surface water is funda-
mental to development of effective water-
resource management and policy,

WATER SUPPLY

.

It has become difficult in recent years to
construct reservoirs for surface storage of
water because of environmental concerns
and because of the difficulty in locating suit-
able sites, An alternative, which can reduce
or eliminate the necessity for surface storage,
is to use an aquifer system for temporary
storage of water, For example, water stored
underground during times of high streamflow
can be withdrawn during times of low stream-
flow. The characteristics and extent of the
interactions of ground water and surface
water affect the success of such conjunctive-
use projects,

Methods of accounting for water rights of
streams invariably account for surface-water
diversions and surface-water return flows,
Increasingly, the diversions from a stream
that result from ground-water withdrawals are
considered in accounting for water rights as
are ground-water return flows from irrigation
and other applications of water to the land
surface, Accounting for these ground-water
components can be difficult and controversial.
Another form of water-rights accounting
involves the trading of ground-water rights
and surface-water rights, This has been
proposed as a water-management tool where
the rights to the total water resource can be

.

.

shared, It is an example of the growing realiza-
tion that ground water and surface water are
essentially one resource,

In some regions, the water released from reser-
voirs decreases in volume, or is delayed signifi-
cantly, as it moves downstream because some
of the released water seeps into the stream-
banks, These losses of water and delays
in traveltime can be significant, depending
on antecedent ground-water and streamflow
conditions as well as on other factors such as
the condition of the channel and the presence
of aquatic and riparian vegetation,

Storage of water in streambanks, on flood
plains, and in wetlands along streams reduces
flooding downstream, Modifications of the
natural interaction between ground water and
surface water along streams, such as drainage
of wetlands and construction of levees, can
remove some of this natural attenuation of
floods, Unfortunately, present knowledge is
limited with respect to the effects of land-
surface modifications in river valleys on floods
and on the natural interaction of ground water
and surface water in reducing potential
flooding,

.

WATER QUALITY

.

Much of the ground-water contamination in
the United States is in shallow aquifers that
are directly connected to surface water, In
some settings where this is the case, ground
water can be a major and potentially long-term
contributor to contamination of surface water,
Determining the contributions of ground
water to contamination of streams and lakes
is a critical step in developing effective water-
management practices,

A focus on watershed planning and manage-
ment is increasing among government agen-
cies responsible for managing water quality
as well as broader aspects of the environment.
The watershed approach recognizes that water,
starting with precipitation, usually moves

.

VI