Upper Mississippi River Clean Water Act Monitoring Strategy 2013-2022 Part 1: Options and Considerations

The Monitoring Options and Considerations document is one of two reports that comprise UMRBA’s 2013-2022 UMR CWA Monitoring Strategy.  The second document is the Recommended Monitoring Plan, which will become available later in 2013.  Ultimately, it is expected that the Strategy, as embodied in these two documents, will lead to annual monitoring work plans and coordinated, interstate monitoring implementation as funding allows.  Presently, there is no unified or comprehensive Clean Water Act (CWA)-focused monitoring strategy for the Upper Mississippi River (UMR).  What exist now are the statewide CWA monitoring strategies of the five UMR states, where each treats the UMR with a differing level of coverage and emphasis.  The result is a monitoring effort by the states for CWA purposes consisting primarily of a limited number of main channel fixed stations where chemical and/or physical data is collected on a frequency ranging from quarterly to monthly.  Spatial design considerations for the interstate UMR pertain to the determination of sampling locations and how the allocation of sampling sites affects what can be accomplished in meeting Strategy goals.  As such, the strategy considers how the spatial aspects of monitoring affect the quality and comprehensiveness of the assessments that result, and how different designs support various CWA program components.  Functions of candidate monitoring designs, as well as their relative advantages and disadvantages in light of Strategy goals, are explored in detail.  Spatial design directly affects how data are used in making assessments and how this also supports planning, effectiveness evaluation, and making management decisions.  It will determine the level of assessment that can be supported, ranging from a one-dimensional determination of status (e.g., the proportion of the entire UMR that is in good, fair, or poor condition), to more detailed and presumably more accurate determinations of status in the different spatial strata, to detailed site-specific determinations with an accompanying diagnosis of impairments.  Further, spatial design dictates how the goals of the strategy will be met – i.e., all of the designs presumably meet the 305[b] and 303[d] goal at some level, but not all provide for the goal of supporting water quality management programs.  Spatial design plays a critical role in how effectively these tasks and desired outcomes can be accomplished.  The discussion of spatial designs that follows separates out mainstem network options from a tributary loading network, the latter serving a very specific function in measuring nutrient and sediment loadings to the UMR.  The mainstem network options seek to support CWA assessment and a broader set of CWA program functions.  For the mainstem, four general types of monitoring designs are considered – fixed stations, probabilistic, stratified random sampling, and longitudinal surveys.  In the case of the tributary loading network, only a fixed station design is considered applicable.  The extent to which the four principal UMR designated uses are assessed varies by each design option, according to the spatial characteristics of the option and how each employs the key indicators.  Each spatial design option brings with it a set of assumptions about how the data collected will be extrapolated to the full extent of the UMR mainstem to support assessment of the four designated uses.  The strategy summarizes how the monitoring design options provide for the assessment of the UMR’s four major designated uses.  Costs are determined for each of the design options and developmental needs are also included.

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