Framing the Question: Challenges in Probabilistic Monitoring of Kansas Streams
Elizabeth F. Smith & Kevin P. Olson
Kansas Department of Health & Environment, Topeka, Kansas
Kansas recently established a new Stream Probabilistic Monitoring Program to support the 305(b) report. Sites are selected probabilistically; established KDHE methods are used to collect water chemistry, habitat, and macroinvertebrate data.
The survey design is unique in two respects. The sample frame is the Kansas Surface Water Register (KSWR), an actively maintained directory of classified waterbodies. In effect, the sample frame defines the target population. Additionally, the design is unweighted. As a result, many sites are in headwater streams. These facts give rise to three questions: What is the effect of using a population-defining sample frame? What proportion of stream mileage is intermittent? How can chemistry and communities be assessed accurately in pooled systems?
Monitoring efforts are independent from maintenance of the KSWR. Because some streams are intermittent, some sample points will be dry at any given time. Strategies for dealing with “nonreportable” mileage will be discussed. Currently, intermittent mileage can be estimated from NHD data (cartographic), USGS data (hydrographic), and Use Assessment Section data (empirical). Data from the Stream Probabilistic Sampling Program will provide a fourth measure, which over time may provide a superior unbiased estimate of drought, dewatering, and similar changes.
Until now, Kansas has monitored streams at targeted, perennial sites. For reaches that are neither completely dry nor freely flowing, monitoring and assessment present a new challenge. Both water chemistry and biological communities may change quickly in pooled systems. Preliminary data from the first year of sampling will be presented, along with plans for addressing these challenges.