Monitoring Watersheds and Streams

Regulations increasingly require monitoring to detect changes caused by land management activities. Successful monitoring requires that objectives be clearly stated. Once objectives are clearly identified, it is important to map out all of the components and links that might affect the issues of concern. For each issue and each component that affects that issue, there are appropriate spatial and temporal scales to consider. These scales are not consistent between and amongst one another. For many issues, unusual events are more important than average conditions. Any short-term monitoring program has a low probability of measuring rare events that may occur only once every 25 years or more. Regulations that are developed from observations of the consequences of small “normal” storms will likely be inadequate because the collected data will not include the critical geomorphic events that produce the physical and biological concerns. Regulations increasingly require monitoring to detect changes caused by land management activities. In its most useful form, monitoring is the job of determining whether some important physical, biological, or social threshold related to some issue of interest has been crossed. Watershed analysis (Regional Interagency Executive Committee 1995) is becoming a widely used approach for identifying the important issues. After the important issues are identified, it is then time to develop some detailed ideas about how those issues are affected, both temporally and spatially. Finally, it is time to decide what to measure, when to measure, where to measure, and how those measurements will be used to address the identified issue. The task is to select the appropriate measurements, at the appropriate times, and in the appropriate places to determine whether there has been an important change to the issue being addressed. A monitoring program that fails to incorporate these first steps is destined to fail. This paper discusses three issues critical to the design of successful monitoring projects: problem definition, scale considerations, and limitations of studies in small watersheds.