Miles and miles of lost or blocked streams. Thousands of acres of lost wetlands. Biological shudders through the underlying ecosystem. Those are some of the potential impacts of a massive mining operation being considered on a landscape near Lake Clark National Park and Preserve in Alaska.

Those impacts are cited in a draft document the Environmental Protection Agency prepared in general to possible mining operations that could arise near the national park. While there are efforts to sink a copper, gold, and molybdenum mine called "Pebble" near the southwestern corner of the park, this study isn't necessarily specific to that proposal, which is still preliminary. Rather, the EPA says it prepared the "assessment to determine the significance of Bristol Bay's ecological resources and evaluate the potential impacts of large-scale mining on these resources."

Nevertheless, the report notes that upwards of 100 miles of streams that might be valuable to "spawning or rearing habitats for Coho salmon, Chinook salmon, Sockeye salmon, rainbow trout, and Dolly Varden (trout)" could be lost or blocked by the Pebble proposal; that more than 4,000 acres of wetlands providing "off-channel habitat" for fish could vanish under the mine's potential footprint, and; that impacts to surface and groundwater flows could harm winter and spring fish habitat.

Additionally, the report tries to picture what could happen if there was failure of a tailings dam built at the mine, or if there was a pipeline failure. Then, too, the EPA notes, the simple existence of large-scale mining operations could adversely affect the culture of the area.

"Under routine operations with no major accidents or failures, the predicted loss and degradation of salmon, char, and trout habitat in North Fork Koktuli and South Fork Koktuli Rivers and Upper Talarik Creek is expected to have some impact on Alaska Native cultures of the Bristol Bay watershed," the Executive Summary reads."Fishing and hunting practices are expected to change in direct response to the stream, wetland, and terrestrial habitats lost due to the footprints of the mine site and the transportation corridor. Additionally, it is also possible that subsistence use of salmon resources could decrease based on the perception of reduced fish or water quality resulting from mining."

What the report doesn't discuss, because the mining proposal is preliminary, is what mitigations the developer would have to take to offset any impacts. Hundreds of sportsmen's groups have urged the EPA to ensure any mining development does not impact the Bristol Bay watershed.

Report Open To Public Comment

Within the draft report, which is open for public comment through June 25, the EPA notes that while the Pebble proposal led to this report, "the analysis is intended to provide a baseline for understanding the potential impacts of mining development throughout the Nushagak River and Kvichak River watersheds."

"The potential mining of other existing copper deposits in the region would likely reflect the same type of mining activities and facilities analyzed for the Pebble deposit scenario (open pit mining, waste rock piles, tailing storage facilities) and, therefore, would present potential risks similar to those outlined in this assessment," the EPA added.

Eyed to be developed just 14 miles beyond the preserve portion of Lake Clark's southwestern boundary, the vision of Pebble has spawned a land rush that since 2003 has seen some 1,000 square miles of state lands adjacent to the park staked with mining claims.

EPA officials announced early in 2011 that they would "conduct a scientific assessment of the Bristol Bay watershed to better understand how future large-scale development projects may affect water quality and Bristol Bay’s salmon fishery, an extraordinary salmon resource for the United States. EPA initiated this assessment in response to concerns from federally-recognized tribes and others who petitioned the agency in 2010 to assess any potential risks to the watershed."

In 2010, nine federally-recognized Bristol Bay tribes petitioned EPA to use its authority under the Clean Water Act to protect Bristol Bay. Their concerns focused on the potential Pebble Mine project. Two other tribes asked EPA to wait for mining projects to submit permit applications before taking action.

The EPA release went on to state that "Bristol Bay is an important source of wild Pacific salmon for commercial, recreational, and subsistence users. It produces hundreds of millions of dollars in annual fisheries revenues. The area may be the last major watershed in North America that produces historic numbers of wild salmon. Most of the Bristol Bay watershed is wildlife refuge or park where large development is restricted. EPA’s efforts will focus on those areas that are not protected."

NPCA: Report Shows Need For More Review

The report, which will be peer-reviewed by an independent contractor, raises questions that merit further examination, according to the National Parks Conservation Association.

“The National Parks Conservation Association strongly supports Alaska’s Native tribal governments who are fighting to defend the wild salmon and clean waters, that are vital to their families’ traditional ways-of-life,” said Jim Stratton, NPCA's Alaska regional director. “As such, we are also closely examining the draft assessment and will be calling on the panel of peer review scientists and other decision makers to factor in the proposed mine’s impact to Lake Clark National Park and Preserve.

“Decisions of this magnitude must be based on sound science and we appreciate the U.S. EPA doing its job by assessing what the risks are to the areas around the special places protected by our national park system in Alaska,” he added in a release.