Big Walnut Watershed

In 2017, the Big Walnut Watershed Alliance launched efforts to protect and improve Big Walnut Creek and its 423 square mile drainage. Big Walnut Creek and Deer Creek. Big Walnut Creek starts in Boone County immediately south of Lebanon and flows southwesterly through northwest Hendricks County into Putnam County. Deer Creek drains the area south and east of Greencastle flowing west to join with Little Deer Creek joining Mill Creek immediately south of US Highway 70.

What is a watershed?

The Big Walnut Creek Project focuses on protecting and improving water quality in Big Walnut and Deer Creeks’ watersheds. All of the land from which water drains into a singular waterbody – in this case Otter Creek – forms a watershed. These drainage boundaries are determined by land elevation rather than state or county lines, political boundaries, or residential property lines.

About Big Walnut Creek

Land within the Big Walnut Creek Watershed is a mix of forested and agricultural land uses with urban development focused around Greencastle with smaller urban communities dotted across the watershed landscape. Tributaries to Big Walnut Creek include Edlin Ditch, Ross Ditch, Tucker Ditch, Owl Creek, Little Walnut Creek, Leatherman Creek, Deer Creek, Plum Creek and more. The headwaters of Big Walnut Creek are largely in agricultural production. The lower portion of the drainage contains wide forested tracts mixed with pastureland and small agricultural fields. Streams within the watershed contain elevated sediment levels with high nutrient and pathogen loads identified at select locations throughout the watershed.

The Big Walnut Creek Project

This phase of the Big Walnut Creek Project includes three main goals:

1. Water Quality Monitoring: Water quality within Big Walnut Creek and its tributaries will be monitored once per month from April to October during the first year of the project. Samples will be collected for a variety of nutrient and sediment parameters and combined within historic water quality data. This compilation will provide a foundation for identifying water quality issues and probable sources of pollutants. The baseline will also provide a foundation for measuring future changes in water quality. Fish and bug communities will also be monitored one time during the project.

2. Education and outreach: The Big Walnut Creek Project will engage youth and adults through Hoosier Riverwatch monitoring; workshops focused on urban and agricultural practices to improve water quality; share your views and opinions as part of our urban and agricultural surveys; and more.

Agricultural Producer Survey: Please input the code next to your name on your postcard. If you do not have a code, enter guest and then add your address. Take the agriculture survey

Urban Resident Survey: Please input the code next to your name on your postcard. If you do not have a code, enter guest and then add your address. Take the urban survey

3. Watershed Management Plan: The Big Walnut Creek Project  will connect stakeholder concerns with water quality and computer generated data to develop a step-wise plan for protecting and improving Big Walnut Creek, its landscape and its water quality. The planning process will include regularly-schedule steering committee meetings with draft plans posted here.

Big Walnut Watershed Planning Documents



Join the Big Walnut Creek Project –

  • Keep up to date with the project on our Facebook page!
  • Share your thoughts on Big Walnut Creek via email or phone at 765-337-9100.
  • Send us data or photographs – how did Big Walnut Creek and its tributaries look in the past? 
  • Join our volunteer list to help with future water sampling, windshield survey, clean up events and more.
  • Share information about the Big Walnut Creek Project with your friends, neighbors and local groups. We’d be happy to talk with you and your group about the project.