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Lefthand Watershed Information

The Lefthand Creek watershed is located north of Boulder and drains around 85 square miles. It covers an area ranging in elevation from 4,000 feet on the plains east of Longmont to over 13,000 feet near the Indian Peaks Wilderness at the Continental Divide. It contains the Lefthand, James, and Little James creeks and numerous small streams flow intermittently through the year.

The Lefthand Creek provides drinking water to about 18,000 residents and agricultural producers in unincorporated Boulder County via the Left Hand Water District. The water is also used in the town of Niwot. Lefthand Water eventually makes it to taps as far east as I 25 in Weld County.

Many of the towns in the upper reaches of the watershed (e.g. Ward and Jamestown) owe their existence to the mining legacy of the area. Mining began soon after the first Europeans arrived and continued through the late 1980s. In the 19th century, the area was one of the richest gold and silver producing regions in the country. More recently tungsten, copper, fluorospar and uranium deposits were mined and processed. A Forest Service survey found 230 mine openings and 186 waste rock piles in the watershed. This mining legacy has created modern water quality concerns as the mines have contributed to the acidification of the water increased the amount of heavy metals entering the streams.

In 1999 the EPA approached Ward and Jamestown about the possibility of areas near or in the towns being added to the Superfund National Priorities List (NPL) to fund necessary cleanup activities. Many folks had serious concerns about the EPA running a cleanup in their backyards. To address this concern, the Boulder County Health Department (BCHD) got a grant to create a community-based task force to explore what listing would actually entail. The taskforce then set up meetings attended both by EPA officials and local citizens to talk about possible outcomes. Following the meetings and recommendations by the task force public opinion changed in Ward and the Captain Jack Mill, below Ward, was added to the NPL list in 2003. Jamestown folks opted out of NPL listing and so the mines in that area are being addressed one project at a time.

An important recommendation by the task force was for the formation of a new group, the Lefthand Watershed Oversight Group or LWOG. Our group was formed to develop a watershed plan to direct future efforts at cleaning up mine wastes. We are a registered 501(c) non-profit and work to improve the water quality of the Lefthand Watershed by getting all the parties who have a vested interest in the cleanups (i.e. stakeholders) to come together and talk about the best way to get things done.

Current Activities
  • Recently concluded a two year study with CU's Prof. Joe Ryan, Susan Bautts, and board member Shannon Phelps examining the metal contamination in the sediments and waste rock piles in the watershed.
  • The LWOG leads a group of dedicated volunteers to monitor sites along the Little James and Lefthand Creeks. Our goal is to determine metal impacts and monitor clean-up effectiveness. Samples are processed and posted online using the Division of Wildlife's RiverWatch Program.
  • Currently we are apdating our watershed plan to incorporate new analysis and to reflect completed clean-ups
  • Begining work on clean-up of Porphyry Site
Lefthand Watershed Oversight Group P.O. Box 1074 Niwot, CO 80544-1074