The 363 square mile Crystal River Sub-watershed is located in the southwestern part of the Roaring Fork Watershed, extending from peaks in the Elk Mountain Range to the Town of Carbondale, where the Crystal River joins the Roaring Fork River. The Crystal River Sub-watershed contributes more than one-half of the peak flows to the Roaring Fork Watershed. The sub-watershed has a long mining history, and extensive areas of sedimentary rock formations significantly influence its landscape, vegetation patterns, and water quality.
Roaring Fork Conservancy, among others, is concerned about human impacts on the Crystal River and in the sub-watershed’s Coal Basin, such as development in and near the riparian corridors, the lingering effects of coal mining activities, and associated land uses, including roads, logging and grazing. Colorado Mesa University analyzed water quality data gathered over more than 50 years, by several third party sources, in order to assess water quality in the Crystal River and Coal Basin and prepare this report. Focusing on 9 sites (5 along the Crystal River and 4 in Coal Basin) it examined the water quality data with the following questions in mind:
- For those parameters that have water quality standards, are the streams in compliance with those standards?
- For each site and water quality parameter, is there a trend over time?
- For each parameter, are there useful or interesting comparisons between sites?
- Are there any other generalizations suggested by the data?
- Does the data adequately characterize existing conditions? Are there any data gaps?
- What recommendations are suggested for future water quality monitoring?
The analysis concluded that the primary water quality problem in the Crystal River and Coal Basin is the iron content in sediments being washed into the river and streams. Approximately 15% of the samples analyzed for total recoverable iron exceeded the Colorado water quality standard for this parameter, which is designed to protect aquatic life.
Dissolved oxygen results fell below the aquatic life-based water quality standard in approximately 8% of all samples. The majority of these problematic results occurred in the Crystal River at Penny Hot Springs in the mid- to late-1990’s. It appears to be a localized problem.
Recoverable arsenic results exceeded the water quality standard in approximately 8% of the samples analyzed. This particular standard is based on the use of a stream for a domestic water supply, which is not taking place in the Upper Crystal River or Coal Creek at the present time. Arsenic does not present a problem for aquatic life.
Approximately 7% of the water temperature results were found to be higher than the temperature limits designated in the applicable Colorado water quality standards, which are also based on protection of aquatic life. However, because these temperature measurements were not conducted in the manner specified in the water quality regulations, they do not represent definite exceedances of the standard. The majority of the high temperature results occurred at Site 3 - the Crystal River above Avalanche Creek. This may be due to the discharge from Penny Hot Springs. More generally, higher temperatures that sometimes occur throughout the area may be a result of shallow water found in channels that have become overly wide due to human activities.
Several other water quality parameters examined exceeded standards less frequently than those described above and are not considered to be a widespread or on-going problem. These parameters include pH, nitrate, cadmium, copper, lead, and selenium.
The purpose of monitoring water quality parameters is not only to compare conditions against state standards, but to detect any trends or patterns that are occurring, such as improvements due to restoration work or degradation due to the occurrence of new problems. The report recommends a quarterly water quality monitoring program to establish a baseline for the Crystal River Sub-watershed. Ideally, all parameters with state standards would be monitored. However, if funding is scarce, monitoring could be limited to parameters that reveal basic aspects of water quality and those that are of the most concern based on historical data and current issues. This list could include temperature, pH, dissolved oxygen, total phosphorous, dissolved iron, total recoverable iron, and selenium. In all cases it is recommended that specific conductance be measured, since it is an easy way to observe changes in total dissolved solids. The following locations are recommended:
- Coal Creek immediately upstream from its confluence with the Crystal River;
- The Crystal River immediately above the confluence with Coal Creek; and
- The Crystal River at a location downstream from the confluence with Coal Creek.
While there is concern about large inputs of sediment into Coal Basin from disturbed areas within its watershed, and input of sediment from Coal Creek into the Crystal River, existing data is inadequate to determine the true extent of this issue. Future water quality monitoring should also include a program to address this data gap.
Annual collections of macroinvertebrates and pebble counts are also recommended for the Crystal River Sub-watershed. Benthic macroinvertebrates are a preferred biological indicator for the assessment of biological integrity, and they are particularly valuable for capturing impacts from episodic events, such as intense rainfall, that routine water quality sampling may miss.