Water Quality Scorecard

Trends Over Time and Geography

The water quality scorecard displays temporal trends for the 6-year period from 2018 through 2023 and also geographical trends, upstream to downstream, in Boulder, Coal, and St. Vrain Creeks. Values in the table are mean annual concentrations for 2023. Shading indicates relative concentrations based on location and parameter specific Benchmarks. Arrows indicate 6-year trends based on a Mann-Kendall analysis. See more details in the expandable sections below.

How to Read the Scorecard

Results are shown in columns by parameter and in rows by location.
Rows are grouped by basin (Boulder Creek, Coal Creek, and St. Vrain Creek).
Sites are ordered upstream-to-downstream (top to bottom in the table).
Geographical Trends: Observe changes in benchmark shading upstream-to-downstream to gain insight into geographic trends on that stream.
Temporal Trends: Observe trend indicator arrows to know whether monitoring from 2018 through 2023 indicates increasing, decreasing, or stable concentrations, or no trend, for that location and parameter.

How Geographic Trends are Calculated

Unique benchmarks were developed by the KICP workgroup for the purpose of visualizing relative concentrations of key parameters by location. Lighter shades in the scorecard indicate lower concentrations, and darker shades indicate higher concentrations.

Benchmark values are parameter concentrations set equal to a stream standard if one exists and otherwise to a value set by the KICP Workgroup chosen to support management goals for the watershed.
The break between below and approaching benchmark is set to a value 20% below the benchmark value for that location and parameter.
Details on how each benchmark is derived can be found in Monitoring Program, Methods and Benchmarks.
Breakpoints between shades are determined by the comparison of the benchmarks to the annual mean concentrations (or geometric mean for E. coli) for that parameter and location in 2023.

How Temporal Trends are Calculated

Trends over time were calculated using a two-tailed Mann-Kendall test, which calculates the statistical significance of an upward or downward trend over time. It also determines a coefficient of variation (CV) which evaluates the variability of the results over the study period. For this analysis, Mann-Kendall results have been characterized as follows:

A statistical significance less than 90% indicates no significant change and is shown as Stable if the calculated CV is less than 1 and No Trend if the CV is greater than 1.
Increasing or Decreasing trends are indicated by a 95% or higher significance associated with the trend.
Probably Increasing or Probably Decreasing indicates there is an 90%-95% statistical significance associated with the trend.

Legend

Benchmark Scores

No Data

Below Benchmark

Approaching Benchmark

Above Benchmark

Trends

Decreasing

Probably Decreasing

Stable

Probably Increasing

Increasing

Please note that shading conveys whether average concentrations of each parameter are below, approaching, or above their respective benchmarks. This is not a standards assessment, and shading does not indicate values are in exceedance of water quality standards.

The tables below include additional 2023 statistics for each parameter and location. A text-definition for each trend indicator is included for the 6-year trends and additional statistics for the 2023 monitoring results include minimum values, maximum values, annual means, 25th and 75th percentiles, and a count of measurements collected for that year at that location.

Quickly jump down to the parameter table of interest by clicking on the info tool for that parameter column in the Scorecard above. Return to the top of the scorecard using the Back up link found at the top of each table.