Watershed Toolshed

Mapping Your Watershed

Maps are basic tools to start people seeing the big picture, literally. Watersheds usually cannot be viewed as a whole from on the ground, so maps are a useful way to make the abstract concept of a watershed concrete. They also allow people to place themselves in a larger context- living upstream from the mill, downstream from the city, etc. It allows individuals to see their connection to the rest of the watershed. For watershed planners, maps can provide an overview of what is known about their watershed, like data points and basic information such as soil type and plant cover. From this vantage it is easier to see how it all fits together, and what data is missing from the picture.

Ultimately, maps allow watershed coordinators to conceive of the whole, and thus affect it.

What Maps Are Already Available?

The Ohio Division of Natural Resources (ODNR), Division of Real Estate and Land Management, has maps of all the watersheds in Ohio, as well as other maps. Watershed coordinators funded through ODNR can request these maps at no charge. Anyone else can contract for them.

Visit the Division of Real Estate and Land Management for more information: http://www.ohiodnr.com/realm/resanalysis/ ocapmain.html

Ohio EPA Division of Drinking and Ground Waters staff can provide information to watershed coordinators on the location of public water system wells, intakes, and drinking water protection areas. This data is available as GIS shapefiles, custom maps, or through a free ArcReader program that enables watershed coordinators to create their own maps.

If you are interested in obtaining this information please contact:

Source Water Assessment and Protection Program Staff
Ohio EPA, Division of Drinking and Ground Waters
(614) 644-2752

Or e-mail:

heather.raymond@epa.state.oh.us

How Can You Make Your Own Maps?

It isn't difficult to make a basic map of your watershed. Simply order a 7.5 minute quad topographic map of your area from the U.S. Geological Survey (available at: http://edcwww.cr.usgs.gov/Webglis/glisbin/finder_ main.pl?dataset_name=MAPS_LARGE).

You can then take a highlighter and outline by hand the boundaries of your watershed, where elevation peaks. If you have data points sampled within your watershed, you could also plot those by hand on a topographic map.

Making More Complex Maps

If you want to make a more detailed map, the easiest way is to use a computer. This method will allow you to map large amounts of data quickly. You will need a GIS-based mapping program and a current computer operating system.

One ubiquitous GIS-based mapping program is ArcView. ArcView is a multi-featured mapping product, and its use may require training. Training costs vary: free training is sometimes offered; certified short courses are available through community colleges; ten week courses are also offered at universities like OSU through their Natural Resources or Geography departments. In addition to training, it may also be wise to arrange for technical support, unless you know an experienced user. More information about ArcView is available at: http://www.esri.com/software/arcview/

The Ohio Division of Natural Resources provides data free for download on their webpage at: http://www.dnr.state.oh.us/gims/. GIS software (such as ArcView) is necessary to read the data files. The available information varies by county, but includes the following categories:

• Administrative: Describes features related to administrative, governmental or regulatory boundaries.
• Biologic: Describes features related to plants, animals and other living entities.
• Cadastral: Describes a boundary that is related to the land fabric, such as parcel ownership.
• Demographic: Describes information primarily related to human population dynamics and activities.
• Geologic/Soils: Describes surfacial or subsurface features of the terrain. Included in this category is information on soils, oil and gas, and mineral resources.
• Hydrologic: Describes features that relate to water, including surface and ground water and precipitation.
• Land Use/Land Cover: Describes features whose primary significance is to what extent they cover the surface of the earth.
• Recreational: Recreational areas include parks, boating areas, wildlife areas, nature preserves, historic sites, etc.
• Topographic: Describes information related to elevation, such as digital elevation models and contour maps.
• Transportation/Infrastructure: Describes features primarily related to transportation routes and utility systems, such as roads, railways or electric transmission lines.

What Should You Do If You Want a More Complex Map, or Want a Professionally-Done Map?

Sources for creating maps include ODNR, local colleges, and the large universities in Ohio, as well as independent contractors. In some cases, 319 grants can be used to pay for mapping.

Who Should You Talk to for More Information?

For general questions and suggestions for services in your local area contact:

Jerry Iles, OSU Watershed Extension Agent
Phone: (740) 286-2177
Fax: (740) 286-1578
Email: iles.9@osu.edu

For questions regarding ODNR maps and about downloading data:

Raymond M. Lohrer, Information Services Planner
Ohio Department of Natural Resources
Division of REAL ESTATE & LAND MANAGEMENT
Resource Analysis Section
1952 Belcher Dr, Bldg C-2
Columbus, OH 43224
Phone: (614) 265-1044
Fax: (614) 267-2981
Email: Mike.Lohrer@dnr.state.oh.us