Las respuestas desde el movimiento campesino

Paired-watershed monitoring design and development problems

Development and completion of a paired-watershed monitoring design to document the effectiveness of BMPs in changing water quality requires a lot of work, communication, and time. The project manager of a paired- watershed monitoring project must be active in coordinating and integrating all aspects of the project, especially in keeping all participants engaged in the project. Specific lessons to be learned from this project include:

• It is important to make sure permission for land access is in place prior to project personnel beginning site reconnaissance much less equipment installation.

• It is important to search out and select land owners/operators that have an interest in participating in a long-term monitoring project and have a relatively stable operation if the project’s success is

dependent on one or a few land owners/operators.

• Be willing to adapt the project to deal with unforeseen events, but make sure any changes are fully documented.

East-West paired watersheds

The lack of significant differences between flow, chloride, and nitrate-nitrogen in the paired-watershed study may be partially explained by the changes in land management during the project that required the BMP treatment to be tested to be changed. The land management changes occurred due to family and

landowner/operator dynamics. While these types of interruptions in the monitoring design could not be controlled, a clearer picture of the family, landowner, and operator dynamics prior to the installation of monitoring equipment may have been enough information to cause the project manager to reconsider the use of the East and West watersheds and look to another setting to complete the project.

The differences in flow pathways documented late in the project may have been an important factor in masking any change in flow or concentration due to the BMPs implemented in the treatment watersheds. The

differences may have been less apparent as the project was being developed given that precipitation and subsequent stream flows were greater than those experienced during the study. Initial comparisons of flow and concentrations between the two paired-watershed monitoring sites also indicated the presence of definite linear relationships, such that an assumption was made that the watersheds could still be used in a paired-watershed study. However, given the differences, three special studies were incorporated into the project.

As discussed above, the special studies provided information that allowed the hydrology of the two watersheds to be compared and contrasted. In hind sight, completion of some of this extra work during the site selection process would have provided information in which to weigh whether or not the hydrology of the watersheds was too complicated to be good candidates for a paired-watershed study. Completion of preliminary monitoring to evaluate site selection can be difficult though given tight timelines and budgets for grant

University of Minnesota watersheds

The three University of Minnesota monitoring sites were incorporated into the NMP project after the plans for the East and West paired-watersheds were completed. This was predicated on the idea that their proximity to the East and West sites would provide additional opportunities for the project to evaluate BMPs through the use of a paired-watershed monitoring design. The results from the monitoring and analysis proved to be less helpful than hoped for given that the farmers managing the land in the watersheds were not consulted

regarding their interest in the study by either continuing their practices as control watersheds or implementing BMPs as treatment watersheds. So, while they were accepting of the monitoring, they were not interested in planning their activities around the project. The design of treatments for the study, therefore, was limited and the treatments described in this report did not occur as the result of planned implementation of BMPs on the part of the NMP project.

The strength of the relationships between the three U of M monitoring sites was less than those between the East and West monitoring sites. In addition to the implementation issues, the greater variability observed between sites may have been the result of the smaller watershed sizes, periods of small to intermittent flows, and loss of data due to equipment problems. The distance of one watershed from the other two also likely influenced the differences in response observed. Nevertheless, calibration period relationships were developed for a few parameters for two treatments. The completion of the subsequent ANCOVA analyses then failed to show any significant difference between the control and treatment periods for either a difference between a corn-soybean crop rotation and CRP nor conventional tillage and chisel tillage practices. The limited results from these efforts demonstrates the importance of in-depth planning, design and landowner participation in developing a BMP effectiveness monitoring project to avoid the uncertainties present when an attempt to incorporate nearby monitoring stations into a project is made.

Biological monitoring

The small scale of the paired-watersheds limited the usefulness of biological monitoring in evaluating changes in water quality in the East and West sites and U of M sites. With this limitation, monitoring sites throughout and adjacent to the Whitewater River watershed were sampled in an effort to incorporate biological monitoring into the NMP project. The biological monitoring completed through the NMP project provided important information in comparing the biotic conditions across different streams, between different parts of individual streams, and over time even though an effectiveness monitoring design was not initially developed. Changes in the biological monitoring sites and methods over the years limited the data record available to evaluate

changes in biotic condition.

The much larger size of watersheds contributing flow to the biological monitoring sites compared to the field scale paired-watershed sites also affected the potential for observing a change in condition that could be attributed to the implementation of BMPs in a watershed. The lack of a BMP implementation tracking system made an evaluation even more difficult. Assuming that the implementation of BMPs in the watersheds of the three Whitewater River branches through the PL566 program was the only difference between those

watersheds and the nearby control watersheds, the significant difference in coldwater fish IBI scores over time between one treatment and control site scenario suggests that BMP implementation resulted in improved biotic conditions in the river. The lack of a significant difference in scores in the other scenarios tested may suggest caution in making the conclusion; however, the general increase in scores over time at the second treatment site on the North Branch of the river and the two sites on the South Branch of the river could also be described as some indication that BMP implementation efforts were beginning to have an effect on the biotic conditions in the rivers. A key factor in making conclusions from this analysis is to recognize the presence of other variables affecting the conditions. In the case of this project, additional analyses to tease out some of the variables were not completed.