An Alum Creek Resource Sheet
Published by the Friends of Alum Creek & Tributaries
Fall 2002
The Watershed
The term “watershed” is one that has
become increasingly important to those working
to protect rivers. It is defined as the area of land
that collects and drains rain water to a particular
water body, such as a lake, river, or wetland.
The Alum Creek watershed drains 200 square
miles and is 55.8 miles long, from its headwaters
in Morrow County south to its confluence with
Big Walnut Creek in southeastern Franklin
County.
which includes 27 miles of stream and
approximately 90 square miles of drainage.
You may have noticed that when
boundaries for counties or cities were
established in Ohio, incorporating rivers and
where their watersheds begin and end were
generally not deciding factors. Although we can
hardly place blame for the practice, it does make
watershed management more difficult as each
city, village, county, and township has a
different approach to river protection. The
lower Alum Creek runs through five
jurisdictions, including Delaware and Franklin
Counties, Columbus, Westerville, Bexley, plus
various townships.
The Alum Creek
Lake Reservoir
Following a national trend, the Friends
of Alum Creek and Tributaries (FACT), in
partnership with local communities and natural
resource management agencies, are addressing
the health of Alum Creek not through politically
sectioned pieces, but through a watershed
approach. Such an approach brings together
decision-makers from all around the watershed
to promote collective action and awareness.
Figure 1: The Alum Creek
Watershed
The Alum Creek as a Resource
For the purpose of this resource sheet,
however, one dividing line does remain. A major
reservoir was built on Alum Creek in southern
Delaware County in 1974, to help prevent
downstream flooding and create a drinking
water supply. The 3,387-acre reservoir is known
as Alum Creek Lake. It was built in the middle
of the Alum Creek watershed and divides the
creek into two distinct segments. This resource
sheet is primarily concerned with the portion of
the watershed that lies below the reservoir,
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The lower section of Alum Creek is
surrounded largely by urban and sub-urban
landscapes that impact the creek in different
ways. Alum Creek is needed by area residents
for drinking water, leisure, and recreation, and
This publication was financed in part by a grant from the Ohio
Environmental Protection Agency and the United States
Environmental Protection Agency, under the provisions of Section
319 (h) of the Clean Water Act.
by industry for water withdrawal and release.
Alum Creek is also home to aquatic life, and its
banks provide habitat for terrestrial wildlife.
Sustaining all of these needs requires balance
among resource uses.
Perhaps one of the creek’s most
important uses is as a public water supply,
including drinking water. Franklin County
depends on creeks and other surface water
bodies for the majority of its water. Two such
water bodies are Alum Creek and the Alum
Creek Lake Reservoir. Alum Creek serves as
the public water supply for the city of
Westerville and portions of Delaware County,
while Alum Creek Lake Reservoir serves as a
back-up water supply for a portion of Columbus.
Municipalities and industries also use
Alum Creek to release or discharge water used
in facility operations. For example, two
wastewater treatment plants (Delaware County
and Huber Ridge subdivision) discharge treated
waters into Alum Creek. Discharges such as
these are regulated by the Ohio Environmental
Protection Agency (OEPA) and require permits.
Currently there are 6 permitted discharging
facilities on Alum Creek, including drinking
water plants and industrial facilities.
The value of creeks extends far beyond
their banks. For instance, Alum Creek is also the
backbone of what city planners call an urban
greenway. A greenway is a corridor or swath of
green space which often follows a river or creek.
Greenways are natural areas that serve as a
sanctuary for city dwellers, offering quietness
and glimpses of wildlife, and other forms of
recreation. A multi-purpose trail is currently
under construction along Alum Creek, and will
eventually extend over 25 miles along the lower
section to join a larger network of trails.
While greenways can provide
alternative routes for commuters and
recreational opportunities for city residents, they
also help preserve a stream’s water quality and
ecological integrity. Alum Creek is fortunate to
have a number of parks along its banks that help
preserve natural areas and form an Alum Creek
greenway.
Conserving “natural” areas adjacent to streams
helps:
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filter pollutants picked up by rain water
running off of urban or agricultural
areas,
provide floodplains that relieve erosion
pressure and remove sediment from
water during flood events,
supply shade and organic debris (such as
falling leaves), which form the basis of
aquatic food chains, and
shape aquatic habitat. For instance,
trees roots along river banks offer
excellent cover for fish.
Land use in the Alum Creek Watershed
The manner in which land within a
watershed is used or developed will determine to
a significant degree the overall health of a
waterway, because land use dramatically affects
how water flows over or through the land.
Land that is covered by forest is able to
hold water, absorbing a large percentage and
allowing water to slowly drain to a creek or seep
through deep soil layers to underground water
sources. By contrast, rainwater that comes into
contact with the hard or impervious surfaces of
an urban environment, such as roads or roof
tops, quickly gains velocity as it runs off into
storm drains. During storms these drains
release a large volume of fast moving water into
streams that can cause severe damage to stream
health. Not only can the fast moving water
erode stream banks and disrupt local
ecosystems, it can also carry pollutants into
streams.
The lower Alum Creek is largely an
urban and suburban watershed with large areas
of impervious surfaces( approximately 17%).
Agriculture and urban lawns make up the largest
land use segment, and much of the remainder of
land – mostly parkland – is forested.
Aquatic Life and Ohio EPA standards
As a result of the Clean Water Act, all
states are responsible for determining what uses
are made of their waters, and assigning water
quality standards that will protect those uses.
Uses (or use designations) fall into two major
categories: aquatic life uses describe the
biological communities a body of water can
support. Non-aquatic life uses describe human
activities including recreational, industrial, and
agricultural activities.
The Alum Creek’s aquatic life use
designation is Warmwater Habitat. Biologists
have evaluated warmwater habitat streams to
determine what kinds of fish and insects can
usually be found in them, as well as typical
water chemistry. From this information they
produce water quality standards which they can
then compare to existing conditions in Alum
Creek to determine its health.
If the stream meets these standards, it is
said to be in “attainment.” If the stream scores
lower than these standards, the stream is said to
be in “non-attainment.”
Large sections of the lower Alum Creek
meet water quality standards and are in
attainment. These reaches fall north or south
(below Route 104) of urban Columbus, seen
below in green. Over eight miles, or about 30%
Park, is in partial attainment. That is, some
standards for health and abundance of fish and
invertebrate (insect) communities are not met,
and habitat for aquatic organisms is poor. One
mile of Alum Creek in the heart of urban
Columbus is in non-attainment. In this stretch
the creek exhibits low biodiversity, a
predominance of pollution tolerant species, and
high incident of fish abnormalities.
Sources of Impairment
The Ohio EPA periodically releases a
comprehensive list of sources of impairments for
the state’s streams (known as the 305 (b) list).
Four major categories of impairment sources
were named for Alum Creek:
 Habitat Destruction
 Construction
 Point Sources
 Urban Runoff / Storm Sewer
Habitat Destruction. As land is developed for
residential or commercial uses, the shape of a
creek or tributary is often changed in a way that
makes it less stable and supportive of aquatic
life. Small streams are sometimes straightened,
lined with cement, or buried underground in a
pipe. Habitat is lost as vegetation along river
banks is removed (see page 2).
Dams can likewise alter river habitats,
which typically take on the characteristics of a
lake when water pools behind the dam.
Damming of streams causes suspended
sediments to drop and cover the stream bottom,
prevents migration of fish and other aquatic life,
and lowers the level of dissolved oxygen in the
water. Alum Creek has four small, or “low
head” dams, with a number of dams located on
its tributaries.
Figure 2: Attainment status of Warmwater Habitat
aquatic life use for lower Alum Creek.
of Alum Creek, from its intersection with I-670
south to the beginning of Three Creeks Metro
Construction: In areas that are experiencing
large urban or sub-urban growth patterns, it’s
not unusual to see construction sites dotting the
landscape. These site are generally prepared by
removing vegetation with heavy machinery,
which can create acres of disturbed land with
bare soils.
These areas become extremely
vulnerable to erosion during rain events.
Sediment is carried by water into streams, where
it can smother organisms living on the river
bottom and harm fish by destroying breeding
and spawning habitats.
Construction can also directly affect
streams by creating hard (or impervious)
surfaces including bridges and roads, which
cross streams and generally impact habitat.
Point Sources: Some sources of pollution come
from a very specific location, such as a pipe, and
are classified as “point sources.” Alternately,
discharges coming from non-discrete or diffuse
points, such as roadways, are known as “nonpoint” sources of pollution.
A major cause of point source pollution
identified by the Ohio EPA for Alum Creek is
sewer overflows. Some older sewage collection
systems are designed to overflow during large
rain events into open waterways to release
excess pressure, and are known as combined
sewer overflows (CSO’s) or separate sewer
overflows (SSO’s).
When CSO’s or SSO’s discharge into
creeks, they introduce bacteria associated with
human excrement, such as fecal coliform.
Bacteria pose health risks and severely limit the
use of water for recreation. Discharges can also
introduce excessive amounts of nutrients, which
off-set the natural balance in aquatic systems
and start a chain reaction that negatively impacts
river life. Bacteria thrive on the increased
nutrients and consume large quantities of
dissolved oxygen. Fish and insects in the water
can subsequently suffocate.
Also of concern are the storm water
collection systems themselves. Built to
efficiently drain water from streets and yards
during storms, they convey large volumes of
water to rivers and inadvertently cause changes
in a stream channel’s “morphology,” or shape.
Rivers respond to the increased flow with
eroding banks, a lowered or “incised” channel
that can no long reach its floodplain, and loss of
critical habitat for fish and insects.
Watershed Action Planning & The Friends of
Alum Creek and Tributaries
Is anything being done to address these
problems? The answer is yes, and it involves
YOU! Community members are coming
together to form an action plan for Alum Creek.
An action plan includes a list of priorities and
actions to be taken to address impairments and
generate positive community action. The plan
will include action strategies, responsible
parties, and a means to evaluate progress. The
watershed approach (see page 1) is the
cornerstone to a good action plan, which means
that broad participation from the community,
including those that are responsible for making
decisions about water policy, must be included.
The Friends of Alum Creek &
Tributaries (FACT) is a non-profit, community
supported organization formed in 1998, and is
the primary sponsor of this action plan. Call
236-6455 for more information and scheduling,
or visit:
www.friendsofalumcreek.org
Urban Runoff / Storm sewers (non-point
source): The last major impairment category is
one that has emerged as the dominant cause of
river impairment nationally, and will perhaps be
the most difficult to improve. Urban runoff
refers to rain water falling on urban areas with
high percentages of impervious surfaces, where
there are unfortunately many opportunities for
the water to pick up pollutants before it drains
into a river. Imagine a parking lot that has been
full of cars which leak gasoline, oil, and perhaps
antifreeze. As it rains, the water carries these
pollutants and others such as fecal coliform,
sediment, and industrial toxic chemicals to name
a few, to local waterways.