Combining societal acceptance and biophysical drivers of conservation practices to improve water quality in multi-use landscapes

Accomplishments / Benefits

Social norms help motivate people to adopt practices that protect water quality

Lay Summary

Our research aimed at understanding the societal acceptance and biophysical potential of conservation practices for reducing nutrient and sediment loading from urban and agricultural sources. We conducted our research in two watersheds in Northwest Indiana, the East Branch–Little Calumet River watershed and the Trail Creek watershed. Both watersheds are located within the larger Little Calumet-Galien (LCG) watershed, which is the only watershed in Indiana that drains to Lake Michigan. We conducted our research in three stages. First, we used an integrated modeling approach to help us quantify current water volume and pollutant loadings from different resident groups (e.g., urban and rural, agricultural and non-agricultural). Second, we used a mail survey to understand how residents in Porter and LaPorte Counties (where the East Branch–Little Calumet River watershed and the Trail Creek watershed are mostly located) perceive water quality problems and what they are doing to reduce water quality problems in terms of adopting best management practices (BMPs). Finally, we developed BMP implementation scenarios based on both biophysical characteristics of the watersheds and watershed residents’ willingness to adopt BMPs. We are currently comparing the modeling results from a range of scenarios with results from the first stage of the project.

Through these three stages of conducting research, we found that watershed residents generally have high levels of awareness of and positive attitudes towards BMPs; however, they are not very likely to adopt any BMPs to improve water quality. We also found that resident groups differ in how they perceive social pressure from peers and others to adopt BMPs to improve water quality. Watershed residents generally value improved environmental quality and reduce flash flood risk as benefits of adopting BMPs, but they do not seem to know enough about specific conservation practices and have concerns about how to install and maintain the practices as main barriers to adoption. Generally, respondents who are younger, perceive more problems with various potential water pollution sources, are more aware of water quality improvement practices, have more positive attitudes, have a stronger sense of personal responsibility, have sought information in the past about water quality problems, or perceive stronger social pressure from peers are more likely to be interested in adopting BMPs to improve water quality in the next year. While information about how to choose, install and maintain specific water quality improvement practices may be useful for watershed residents, the effect may be different based on their initial perceptions about water quality problems. Information alone is unlikely to change the willingness to adopt BMPs among people who feel very positive or negative about water quality problems to begin with; however, information may play a role among people who do not have strong feelings about water quality problems.

Initial results from the watershed model showed that agricultural regions, in particular cropland, produce higher loads of N, P, sediment, and E. coli than urban and suburban regions. This trend remained when the loads were corrected for area of the watershed within each land use type. We also learned from our surveys that agricultural land owners were more knowledgeable and likely to implement BMPs than their urban counterparts. We used both biophysical and social information to develop several BMP implementation scenarios, including (1) implementation of urban/suburban BMPs in all available land, (2) implementation of agricultural BMPs in all available land, and 3) implementation of both urban/suburban and agricultural BMPs at percentages in which the residents were both knowledgeable and willing to implement them. We are currently running these scenarios and will compare results to range of BMP adoption scenarios in both land uses to understand the complexities in pollutant reduction at the watershed scale. By doing so, we will be able to understand the realistic potential of using BMPs to reduce water pollution in our watersheds, and identify groups of residents within the watersheds who could be targeted for increased education, assistance, and incentives to promote adoption of conservation practices


Purdue Extension

Northwest Indiana Regional Planning Commission

Research Information

Principal Investigator:
Zhao Ma
Initiation Date:
Completion Date:
Purdue University