Monitoring Small Agricultural Watersheds to Motivate and Evaluate Conservation Actions

Monitoring Small Agricultural Watersheds to Motivate and Evaluate Conservation Actions

Authors: Jimmy Webber, John Clune, Alex Soroka, Josh Kasper, Mark Nardi,
Hilary Dozier, and Nick Grim

PDF Version available here

Motivation for the Study

Farmers throughout the Chesapeake Bay watershed are volunteering to use conservation practices on their land. Many of these practices can lower nutrient and sediment loads in local streams. However, it is difficult to identify the effect of conservation practices in larger rivers. Therefore, additional research in small watersheds can be used to guide effective water-quality management strategies in agricultural landscapes.

In a 2021 report, a federal monitoring team of experts from the USGS, USEPA, and NRCS identified the need for enhanced monitoring at finer scales to better connect conservation practices with water-quality changes. This study is designed to address the lack of long-term monitoring studies in small agricultural watersheds.
Through partnership with local communities and long-term monitoring of agricultural streams, this study can help identify how streams are responding to agricultural conservation activities.

Objectives

The overall objectives of this study are:

1. To build partnerships with agricultural communities.
2. To evaluate the effects of agricultural conservation practices on water-quality responses.

Site Selection

Based on feedback from scientific and conservation partners, five study watersheds were selected in 2024. These watersheds met the following criteria:

1. Size: “small” watersheds: less than 20 mi².
2. Land Use: intensive agricultural areas.
3. Location: representative watershed settings.
4. Partnership: areas where agricultural partnerships could be developed or strengthened.
5. Conservation: areas targeted for future agricultural conservation practices.

Nested Watersheds

Little Conewago Creek and War Branch are nested within existing study areas, providing an opportunity to assess upstream and downstream water-quality patterns.

Conservation Priority Areas

All watersheds are focus areas for future conservation through local TMDLs, NRCS initiatives, and/or local partnerships.

Water-Quality Monitoring

Long-term monitoring is designed to identify water-quality differences across agricultural watersheds and water-quality changes over time.
Three foundational types of data collection began in 2024 in each watershed:

1. Real-time streamflow
2. Monthly and storm-targeted water-quality samples
3. Continuous water-quality data

Continuous Nitrate Data

15-minute nitrate-as-N concentrations are being measured at each station. These data reveal detailed nitrogen patterns and, with streamflow, can be used to calculate loads. Explaining these and other water-quality patterns relies on detailed knowledge of watershed activities

Building Partnerships

In addition to the federal, state, and academic partners who are supporting this work, this study is focused on increased engagement with local agricultural communities.
Working together with local agricultural communities can strengthen our understanding of water-quality responses. These partnerships can ensure that we’re fully accounting for conservation actions taken by farmers.

Study Expansion and Collaboration

In partnership with NRCS, five additional agricultural stations will be installed in Pennsylvania, with three in the Chesapeake Bay watershed.
We’re working with other partners and agencies to add data collection and additional interpretative work to this study, such as benthic monitoring and geospatial analyses.
This study provides many collaborative opportunities with the USGS research community. We want to work with you!