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National Water-Quality Assessment Program
Great and Little Miami River
Basins
Fact Sheet FS-117-97, August 1997
Implementation of a National Water Quality Assessment (NAWQA)
Program study in the The Great and Little Miami River Basins area will increase
scientific understanding of natural processes and human activities that affect
the quality of water in streams and aquifers. This information will benefit
water-resource managers that need, but often lack, the data required to
implement effective water-quality management actions and evaluate long-term
changes in water quality.
(Larger Version 26K)
Figure Caption: Blue sucker, one of Ohio's rarest
and most endangered fish species, has recently been identified in the Little
Miami and Great Miami Rivers. The occurence of the pollution-sensitive species
indicates improving stream quality in both watersheds.Water quality has
improved significantly in the Great and Little Miami River Basins over the past
few decades because of improvements in the treatment of municipal and industrial
wastes. However, the effects of industrialization and urbanization on the
quality of rivers and ground-water resources remain a priority concern of
water-resource managers and planners, state and local governments, and citizen
groups. Some of these effects relate to nonpoint sources of contaminants and are
the subject of ongoing research and watershed management projects such as the
Lower Great Miami Watershed Enhancement Program, the Little Miami Partnership,
the Stillwater Watershed Project, Indian Lake Watershed Project, and the Miami
Conservancy District's Groundwater 2000 Program. Water resource managers in the
Great and Little Miami River Basins area are currently addressing the following
water-quality issues:
- Contamination of the sole-source Miami Valley aquifer
by synthetic
organic chemicals, trace elements, and
radionuclides.
- Degradation of surface- and ground-water quality by urban
and
agricultural sources of fertilizers and pesticides.
- Assessing the relative importance of point and nonpoint
sources to
contaminant loads in the Great and Little
Miami Rivers.
- Habitat degradation and decreases in stream biodiversity
as a result of
urbanization.
- Occurrence of water-borne pathogens in streams and shallow
ground water
in rural and urban land-use settings.
- Effect of septic systems and combined sewer overflows on
surface- and
shallow ground-water quality.
- Disruption and fragmentation of stream habitats by low dams
and
impoundments and their effects on fish and benthic
invertebrate
communities.
During the past 25 years,
government and industry have made large financial investments aimed at improving
water quality across the Nation. Although major progress has been made, many
water-quality issues remain. To address the need for consistent and
scientifically sound information for managing the Nation's water resources, the
U.S. Geological Survey began a full-scale National Water Quality Assessment
(NAWQA) Program in 1991. The overall goals of the NAWQA Program are to (1)
describe current water-quality conditions for a large part of the Nation's
freshwater streams and aquifers (water-bearing sediments and rocks), (2)
describe how water quality is changing over time, and (3) improve our
understanding of the principal natural and human factors affecting water
quality.
(Larger Version 3K)Assessing the quality of water in every location of
the Nation would not be practical; therefore, NAWQA Program studies are planned
within a set of areas called study units. These study units are composed of 59
important river and aquifer systems that represent the diverse geography, water
resources, and land and water uses of the Nation. The Great and Little Miami
River Basins constitute one such study unit. The study unit includes (1) three
important tributaries of the Ohio River, (2) largely agricultural watersheds
affected by two major metropolitan areas and rapid urbanization, and, (3) a
Nationally important sole-source aquifer that is heavily used for public water
supply. Study-unit activities in the Great and Little Miami River Basins began
in 1997.
Surface Water.The Great
and Little Miami River Basins drain approximately 7,350 mi2 (square
miles) of southwestern Ohio (80 percent) and southeastern Indiana (20 percent).
Principal streams include the Great Miami River (4,124 mi2), and
Little Miami River (1,756 mi2) in Ohio and the Whitewater River
(1,474 mi2) in Indiana. Drainage is toward the south-southwest; all
streams in the watershed ultimately drain into the Ohio River. Major tributaries
of the Great Miami River include the Stillwater River (676 mi2) and
the Mad River (657 mi2), both of which join the Great Miami River at
Dayton, Ohio.
Rivers originate in the upper reaches of the basins in agricultural areas
consisting of rolling hills and steep-walled but shallow valleys. Large streams
are usually underlain by buried valleys filled with sand and gravel deposited by
glacial meltwaters. A significant component of baseflow in some streams is
provided by ground-water discharge from glacial and shallow bedrock aquifers.
The area contains many lakes and small reservoirs that are used for flood
control, water supply, and recreation. The largest water bodies in the study
unit are Brookville Lake (8.2 mi2) near Brookville, Indiana and
Indian Lake (8.0 mi2) near Russells Point, Ohio; Indian Lake was
constructed in 1851 to supply water to the Miami-Erie Canal System.
(Larger Version, 26K GIF)
East Fork Little Miami River near Batavia,
Ohio. Physical habitat of many reaches of major streams in the study area is of
good to exceptional quality, consisting of riffle/run/pool sequences associated
with forested riparian corridors (Photo courtesy of Ohio Environmental
Protection Agency)
Population and Land Use. An estimated 2.8 million people lived in the
study unit in 1995. Major cities (population greater than 100,000) in the study
unit are Cincinnati and Dayton, Ohio. Approximately 79 percent of the total land
area is used for agricultural activities, primarily row-crop production of corn,
soybeans, and alfalfa. Residential, commercial, and industrial land uses
comprise 13 percent of the area whereas the remaining area consists of forests
(7 percent) and water bodies or wetlands (1 percent). Major industries, which
are concentrated along the Dayton- Cincinnati corridor, produce automobile
parts, business and computer equipment, chemicals, household goods, paper
products, and processed foods and beverages. Streams and lakes in the study unit
are heavily used by residents for boating, fishing, and other outdoor
recreation.
(Larger Version, 17K GIF)
Largemouth bass from Great Miami River near
downtown Dayton. High-quality streams contribute to a diverse sports fishery
used by many residents (Photo courtesty of Ohio Environmental Protection
Agency)
Physiography and Climate. The Great and Little Miami River Basins are
in the Till Plains section of the Central Lowlands Physiographic Province.
Glaciation and subsequent erosion produced a flat to gently rolling land surface
that is cut by steep-walled river valleys of low to moderate relief. In the
southernmost areas, glacial cover is thin and erosion of the less resistant
shales has produced a more dissected, hilly terrain of higher stream density.
The regional topographic gradient is from north to south; altitudes in the study
unit range from 1,550 feet above sea level near the headwaters of the Mad River
to 450 feet along the Ohio River at Cincinnati. Average annual precipitation in
the study unit ranges from 35 to 43 inches and increases towards the south;
about one-third of the precipitation becomes surface runoff. Average annual air
temperature ranges from 51° Fahrenheit in the north to 54° in the south. Average
snowfall in the study unit is 20 to 30 inches per year.
Ground Water. The principal aquifer in the study unit is a complex,
buried-valley system that underlies the Great and Little Miami River valleys.
This aquifer has been designated a sole-source aquifer by the U.S. Environmental
Protection Agency and is the principal source of drinking water for 1.6 million
people. The aquifer is found in bedrock valleys incised into uplifted Silurian
and Ordovician bedrock by a tributary of the Teays preglacial drainage system.
These valleys were buried by sediments deposited by advancing glaciers (tills)
or filled in by coarse-grained sediments deposited by glacial meltwaters
(outwash). Depth to water in most parts of the aquifer is less than 20 ft;
supply wells completed in the sand and gravel deposits commonly yield more than
1,000 gallons per minute. At several locations, high pumping rates are
maintained by induced infiltration of river water or by artificial recharge
lagoons. In the northern part of the study unit, Silurian limestones and
dolomites form a carbonate bedrock aquifer that is used for domestic and small
industrial supply. Wells completed in the carbonate aquifer typically yield
between 10 and 100 gallons per minute. In the southern part of the study unit,
the shale-rich Ordovician bedrock is poorly permeable and is used for
domestic-water supply only where other sources of water are not available.
(Larger Version, 32K GIF)
Confluence of Mad and Great Miami Rivers at
Dayton, Ohio. Despite being at the confluence of three major streams, Dayton
relies almost entirely on ground water from a sole-source aquifer for municipal
and industrial water supply (Photo courtesty of Joel Kane Aerial Photography,
Dayton Ohio).Water Supply. In 1995, an estimated 745 million
gallons per day was withdrawn from streams and aquifers in the Great and Little
Miami River Basins. Of this, approximately 48 percent was withdrawn from
surface-water bodies whereas the remaining 52 percent was derived from
ground-water sources. Excluding withdrawals from the Ohio River, almost 92
percent of the water used for public, domestic, commercial, and industrial
supply was derived from ground-water sources. Most of this ground water is
pumped from the buried-valley aquifer underlying stream valleys associated with
the Great and Little Miami Rivers.
Although rivers in the Great and Little Miami River Basins greatly influenced
the early development of the region's economy, it has been the availability of
abundant ground-water supplies that has spurred rapid growth and development in
the region since the beginning of this century. Another important factor
affecting growth and development is the relatively unspoiled nature of the
streams and rivers. The Little Miami River (a State and National Scenic River),
the upper Great Miami River and its tributaries, and the Whitewater River in
Indiana largely contain high-quality warmwater habitats with biologically
diverse fish and wildlife populations.
(Larger Version, 9K GIF)
Study-area map.
(Larger Version, 5K GIF)The Great and Little Miami Basins study is one
of a set of NAWQA Program studies that will start in 1996 and 1997. Planning,
study design, and analysis of existing data will occur in the first two years of
the study. After the 2-year planning period, ground-water, surface-water, and
biological data are collected intensively for 3 years (termed the high-intensity
phase). A low-intensity phase follows for 6 years, where water quality is
monitored at a selected number of sites and areas assessed during the
high-intensity phase. The second cycle of the study begins in 2007. This
combination of high- and low-intensity monitoring phases allows the NAWQA
Program to examine trends in water quality over time.
During the planning period, existing data and results from previous studies
are reviewed to help understand the primary physical, chemical, and biological
factors that affect water quality in the study unit and to identify gaps in the
current data. Descriptions of how land use and land cover, soils, geology,
physiography, climate, and drainage characteristics may influence water quality
are to be included in technical and non-technical reports. These reviews, along
with field checks of existing monitoring stations and candidate sampling sites,
and field reconnaissance data are used to design a sampling program for the
study unit.
During the high-intensity phase, new water-quality and biological data
collections are done for selected areas at both local and regional scales to
describe water-quality conditions across the study unit. Measurements are made
to determine water chemistry in streams and aquifers; the quantity of suspended
sediment and quality of bottom sediments in streams; the variety and number of
fish, benthic invertebrates, and algae in streams; and contaminants in fish
tissues. Individual streams and aquifers, particular chemical constituents, and
biological species are selected for sampling to represent the primary water
resources and water-quality concerns for both the study unit and the Nation. The
low-intensity phase will continue monitoring at selected sites so that long-term
trends can be identified. A series of technical and non-technical reports
describing results of high and low-intensity phase are planned.
The NAWQA Program is designed to assess the status of
and trends in the quality of the Nation's ground- and surface-water resources
and to link the status and trends with an understanding of the natural and human
factors that affect the quality of water. The design of the Program balances the
unique assessment requirements of individual study units with a nationally
consistent design and data-collection structure that incorporates a multiscale,
interdisciplinary approach. Surface- and ground-water studies are done at local
scales (a few square miles to hundreds of square miles) and regional scales
(thousands of square miles) to aid in the understanding of water-quality
conditions and issues within a study unit.
An Occurrence and Distribution Assessment is the largest and most important
component of the first intensive study phase in each study unit. The goal of the
Occurrence and Distribution Assessment is to characterize, in a nationally
consistent manner, the broad-scale geographic and seasonal distributions of
water quality in relation to major contaminant sources and background
conditions. The following discussions describe the typical surface- and
ground-water monitoring components of the Occurrence and Distribution
Assessment. The Great and Little Miami River Basins NAWQA study will have a
similar design.
Surface Water The national study design for surface water focuses on
water-quality conditions in streams using three interrelated components --
water-column studies, bed-sediment and fish-tissue studies. Water column studies
monitor physical and chemical characteristics, which include suspended sediment,
major ions, nutrients, organic carbon, and dissolved pesticides, and their
relation to hydrologic conditions, sources, and transport. Most surface water is
monitored at sites termed either basic fixed sites or intensive fixed sites,
according to the frequency of the sampling. The sampling sites are selected to
determine the quality of water in relation to important environmental settings
in the study unit. Most NAWQA study units have 8-10 basic fixed and 2-3
intensive fixed sites. Basic fixed sites are sampled monthly and at high-flows
for 2 years of the 3-year high-intensity phase. The intensive-fixed sites are
monitored more frequently (as often as weekly during key periods) for at least 1
year, to characterize seasonal variations of water quality. Basic or intensive
fixed sites can be either indicator or integrator sites. Indicator sites
represent relatively homogeneous, small basins (typically less than 100 miČ)
associated with specific environmental settings, such as particular land use
that substantially affects water quality in the study unit. Integrator sites are
established at downstream points in large, relatively hetergeneous drainage
basins (thousands of square miles) having mulitple land-use settings. Indicator
sites are typically placed within the drainage basins of integrator sites. Water
samples also are collected as part of synoptic (short-term) investigations of
specific water-quality conditions or issues during a specific hydrologic period
(for example during low streamflow) to provide greater spatial coverage and to
allow investigators to assess whether the basic fixed or intensive fixed sites
are representative of streams throughout the study unit. Bed-sediment and
fish-tissue studies assess trace elements and hydrophobic organic contaminants
at 15-30 sites to determine their occurence and distribution in the study unit.
Ecological studies evaluate the relations among physical, chemical, and
biological characteristics of streams. Aquatic biological communities at the
basic and intensive fixed sites are surveyed during the 3 years of the
high-intensity-sampling phase. These surveys are made along a delineated stream
reach and include a habitat assessment of the site and annual surveys of the
fish, algal, and benthic invertebrate communities. Additionally, ecological
sampling may be integrated with surface-water synoptic studies to provide
greater spatial coverage and to assess whether the biological communities at
basic and intensive fixed sites are representative of streams throughout the
study unit.
COMMUNICATION AND COORDINATION
Communication and
coordination between the U.S. Geological Survey and other scientific and land-
and water-management organizations are critical components of the NAWQA Program.
Each study-unit investigation maintains a liaison committee consisting of
representatives from Federal, State, and local agencies, universities, the
private sector, watershed organizations, and those who have water-resource
responsibilities and interests. Activities include the exchange of information
about regional and local water-quality issues, identification of sources of data
and information, assistance in the design and scope of study products, and the
review of study planning documents and reports. The Great and Little Miami River
Basins liaison committee will be formed in 1997.
SUGGESTIONS FOR FURTHER READING
Gilliom, R.J., Alley, W.M., and Gurtz, M.E.,1995, Design of the National
Water-Quality Assessment Program: Occurrence and distribution of water-quality
conditions: U.S. Geological Survey Circular 1112, 33 p.
Leahy, P.P., Rosenshein, J.S., and Knopman, D.S., 1990, Implementation plan
for the Nation Water-Quality Assessment Program: U. S. Geological Survey
Open-File Report 90-174, 10 p.
FOR MORE INFORMATION
Information on technical reports and hydrologic data related to the
NAWQA Program can be obtained from:
Gary L. Rowe, NAWQA Study Chief
U.S. Geological Survey
Water Resources Division
6480 Doubletree Avenue
Columbus, OH 43229-1111
(614)430-7729
E-mail: nawqa_miam@usgs.gov
Internet: http://water.usgs.gov/nawqa/nawqa_home.html
By: Gary L. Rowe and Nancy T. Baker
Layout by: Richard P. Frehs
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