But state statutes that govern the Mined Land Reclamation Board, which issues gravel-mining permits, do not require consideration of the impacts multiple mines could have on water and air quality, flooding, or quality-of-life issues such as traffic, noise and visual impacts.

A group called Citizens for Accountability and Responsibility has argued that they should, and Larson is seeking evidence that clarifies whether that is the case or not.

Representatives from the Colorado Water Conservation Board with expertise in watershed management will visit the river valley this summer to determine if CFAR’s claims that the mines are problematic merit additional study.

"It is an opportunity for the county to utilize state resources not available locally," Larson said. "Mined Land Reclamation keeps bumping up against the statute’s limitations" on cases where opposition is strong.

Larson said that if state experts believe there is a legitimate concern, the commission would be consulted about conducting a more comprehensive analysis using available state and federal grant funding.

The commission was generally agreeable, but warned that the study needs to be fair and objective, cannot jeopardize mine permits already approved by the commission, and must take into consideration the market demand for construction gravel.

"The cumulative effects of gravel pits is a ratio to the cumulative impacts of housing development and demand, so that needs to be kept in mind," said commission chair Kent Lindsay.

CFAR has been raising concern about gravel pits in the Dolores Valley and their negative impacts. The group has been lobbying for a stricter interpretation of state laws regulating mining’s effects on health and the environment, and fears a large flood could contaminate McPhee Reservoir and water wells with silt.

Commissioner Gene Story said that CFAR had done "good work" and that the commission should not "back off" issues they have raised.

"But, that is our source of gravel," Story added. "We need to consider the high value of gravel there, (but) we need to also consider the best use of gravel considering the impacts."

For instance, Story said, using high-quality river gravel ideal for cement products as a road base instead of for construction cement does not make sense and such differences should play a role in the regulating process.

"We need to start asking, ‘Why do you want to mine that type of gravel when it is available elsewhere?’ " he said.

"We are very pleased that there is recognition in the legislature of the potential dangers of gravel-mining in the flood plain and the lack of adequate state control," said Pat Kantor, CFAR board chair. "The (MLR) has admitted to us that they have no data at all on the effects of multiple pits in proximity to each other."

Larson was careful not to divide the issue into pro- or anti-gravel stances, or imply that the proposed study was an attempt at reversing permits approved by the commission. Rather, as growth impacts begin to outgrow mining regulations created 25 years ago, updating those laws should be considered, he said.

"I’m with you on the need for gravel and the right for people to mine gravel on their property," Larson said. "This is a constituent issue that is not going away. It has come to my attention here and also in Archuleta County, so I felt compelled to do some legwork on it."

Future permits may need additional requirements, Larson said, to better mitigate the concerns of citizens and the environment. But limiting development in general, whether subdivisions or mines, in sensitive regions may be part of the answer as well, he said.

"I have people complaining about gravel operations who purchase that same gravel for use in their own neighborhoods and projects," Larson said.