Big Darby Subwatershed Plans
to Address Water Quality Concerns
The Subwatershed Plans
How to view your subwatershed plan
The Total Maximum Daily Load (TMDL) document addresses
water quality concerns according to the clean water act and asks the community
to help address them. Landowners and residents have a few additional
concerns such as flooding, drainage and log jams. The goal of the Darby
Community based watershed plan is to give the landowners and residents the
information that we need to implement a plan to protect their watershed in
ways that make sense to our community.
Watershed is one of the most tested and observed watersheds in Ohio because
of its water quality; in turn it supports a wide range of bugs, fish and
mussels, some of which are endangered and threatened.
The Darby Watershed consists of 555.6 square miles, 74%
is used for agriculture and 22% is wooded land.
The watercourses which make up the watershed include the main stems of
Big and Little Darby Creeks as well as the tributary streams and channels that
contribute water to the main stems.
Agricultural land is the primary reason that the Darby is in good health and can
support a wide variety of bugs, fish and mussels.
Due to the agricultural nature of this watershed, development pressures
have been minimal and the villages and cities continue to invest in upgrades to
their wastewater treatment plants. A
perfect score for fish was recorded in the Little Darby Creek in 1985 and 1987,
south of the
wastewater treatment plant. A
perfect score has only occurred at a handful of sites throughout
In 2001, the Darby Joint Board and many volunteers within the watershed began
the long and complicated process of developing a community based watershed plan.
The watershed plan reflects the belief that the people who live in the watershed
are the ones who should decide how the watershed is to be managed.
With this in mind, the Joint Board of Supervisors elected to construct
the Darby document different from other watershed plans.
Many watershed plans become cumbersome to read and understand.
The Board wanted to make the Darby document easy to understand and use.
Therefore, the watershed was divided into 17 subwatersheds by using
Global Positioning System (GPS) and Geographic Information System (GIS) to
create maps. Each subwatershed
is in its own section and all have the same format so that you can “pull
out” only the areas that are of interest.
’s 15% of the watershed has development issues that are totally different from
the remaining watershed,
elected to create their own document through the Darby Accord and the
Hellbranch Forum. Questions
documents may be addressed to:
The Hellbranch Forum at Franklin
County Soil and Water Conservation District (SWCD) or for information about
the Darby Accord
contact Reza Reyazi of the City of
at (614) 645-3898.
The 16 agricultural subwatershed documents indicate what is in that
subwatershed: historical testing
data; items that may be of concern; sites the Ohio Environmental Protection
Agency (OEPA) decided were in full, partial or non
attainment and the existing
government programs and local agencies that are available to that subwatershed.
During the summer of 2001-2002, OEPA tested 127 sites.
Of these sites, 84 (66%) were in full
attainment, 31 (24%) were in partial
attainment, and only 12 (9%) were found to be in non
is a term describing the degree to which environmental indicators (fish, bugs,
and habitat) are either above or below criteria specified by the Ohio Water
Quality Standards (WQS).
The OEPA considers every watercourse to be a stream.
However, the Joint Board of Supervisors adopted a list of definitions
that better describe each watercourse based on its purpose and history. For
example, the Darby Joint Board does not consider agricultural drainage channels
to be streams since they were constructed to drain agricultural lands. A
list of the watercourse definitions and a map of
the defined watercourses can be found in each subwatershed document.
The Darby Joint Board is dedicated to listening to landowners/residents of the
watershed. In a landowner
survey and many subwatershed public meetings, the Board asked
landowners/residents about concerns regarding their subwatersheds. The most
frequent comments were log jams, stream bank erosion and how each affects
The Darby Joint Board believes in order for subwatershed plans to function
properly; input must come from the landowners. Therefore all sections of the
document are meant to be updated on a continual basis as landowners/residents
tell us where erosion, log jams, flooding etc. are
With this information each subwatershed, will have input on what
should be done and who should be involved to improve these issues.
This plan is a “living document” which means that it
will adapt to the needs of landowners/residents and the watershed on a continual
basis through updates as numbers, programs, etc. change.
As with agriculture, this plan is adaptable and changeable.
Agriculture is the secret of the Darby Watershed’s continued health and
diversity and with the assistance of the landowners/residents of the watershed,
this will continue into the future.
encourage you to comment
on this watershed plan by going to the comments
section of the website or by emailing the watershed
Each plan has the same layout
data shows the historical data for the subwatershed.
Definitions- Some tributaries of the Darby become dry so we use these
definitions to delineate this. These are also mapped.
- Agricultural Section- land use, drainage, slope and erosion, tillage
practices, crop rotation and manure and nutrient management
- Riparian Areas- Watercourse Lengths, County maintained channels (ditches),
watercourse modification, riparian vegetation and floodplain data.
- Rural Housing Sprawl- shows the growth in the subwatershed. Data
is taken from the 2000 census of townships and cities or villages within
the watershed. New building permit data is from the local
official. Golf course information as
septic system data is also
included in this section.
- Water Quality- Point sources, stream/channels that are in partial or
non-attainment and recommendations for those sites.
- Schedule of Implementation- This section tells the goals of each
- Maps- There are four of five maps per subwatershed. The first map
is the location map. The land use map is based on the 1997 hybrid
land use data. The third map uses the stream/channel
definitions and the fourth map shows the riparian buffers. The
fifth map is only included for subwatersheds near Marysville.
Marysville is in the process of constructing a new Waste Water Treatment Plant (WWTP) and this map shows the areas that will be served by the new
There are two ways you can view y our watershed plan. If you know the name
of your subwatershed(s), click here.
If you would prefer to select your subwatershed by selecting it on the map,