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

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through the subsurface before entering stream
channels and flowing out of the watershed,
Integrating ground water into this "systems"
approach is essential, but challenging, because
of limitations in knowledge of the interactions
of ground water and surface water, These diffi-
culties are further complicated by the fact that
surface-water watersheds and ground-water
watersheds may not coincide,

To meet water-quality standards and criteria,
States and local agencies need to determine the
amount of contaminant movement (wasteload)
to surface waters so they can issue permits and
control discharges of waste, Typically, ground-
water inputs are not included in estimates of
wasteload; yet, in some cases, water-quality
standards and criteria cannot be met without
reducing contaminant loads from ground-
water discharges to streams,

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It is generally assumed that ground water is
safe for consumption without treatment.
Concerns about the quality of ground water
from wells near streams, where contaminated
surface water might be part of the source of
water to the well, have led to increasing
interest in identifying when filtration or treat-
ment of ground water is needed,

Wetlands, marshes, and wooded areas along
streams (riparian zones) are protected in some
areas to help maintain wildlife habitat and
the quality of nearby surface water, Greater
knowledge of the water-quality functions
of riparian zones and of the pathways of
exchange between shallow ground water and
surface-water bodies is necessary to properly
evaluate the effects of riparian zones on water
quality.

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CHARACTERISTICS OF
AQUATIC ENVIRONMENTS

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Mixing of ground water with surface water can
have major effects on aquatic environments
if factors such as acidity, temperature, and

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dissolved oxygen are altered, Thus, changes in
the natural interaction of ground water and
surface water caused by human activities can
potentially have a significant effect on aquatic
environments.

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The flow between surface water and ground
water creates a dynamic habitat for aquatic
fauna near the interface, These organisms
are part of a food chain that sustains a
diverse ecological community, Studies
indicate that these organisms may provide
important indications of water quality as
well as of adverse changes in aquatic
environments.

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Many wetlands are dependent on a relatively
stable influx of ground water throughout
changing seasonal and annual weather
patterns. Wetlands can be highly sensitive to
the effects of ground-water development and
to land-use changes that modify the ground-
water flow regime of a wetland area, Under-
standing wetlands in the context of their asso-
ciated ground-water flow systems is essential
to assessing the cumulative effects of wetlands
on water quality, ground-water flow, and
streamflow in large areas.

The success of efforts to construct new
wetlands that replicate those that have been
destroyed depends on the extent to which the
replacement wetland is hydrologically similar
to the destroyed wetland, For example, the
replacement of a wetland that is dependent on
ground water for its water and chemical input
needs to be located in a similar ground-water
discharge area if the new wetland is to repli-
cate the original. Although a replacement
wetland may have a water depth similar to the
original, the communities that populate the
replacement wetland may be completely
different from communities that were present
in the original wetland because of differences
in hydrogeologic setting,

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