In 1998, Boulder County approved a special use permit to allow gravel mining on 881 acres of property owned by Western Mobile in the St. Vrain River Valley east of Lyons. River valleys are often targeted for gravel mining due to the accumulation of gravel and other sediments that build up in floodplains.
In 2011, the land was sold to Martin Marietta Materials Inc., which is now seeking to continue gravel mining operations on the property. Included with the mines, they’re also planning to build a number of accessory structures within the 100 year flood plain of St. Vrain Creek.
The special use permit included a clause that the permit will lapse if no activity authorized under the permit has been conducted for a continuous period of 5 years or more. On April 11, 2018, Boulder County ruled that the permit is still valid. However, prior to the onset of mining operations, the Boulder County Board of Adjustment must hold public hearings on the proposal.
The first of such public hearings is scheduled for Wednesday, June 6, 2018. The appeal hearing begins at 4:00 PM at the Commissioner’s Hearing Room, 1325 Pearl St., Boulder, CO 80302.
You can find more information about the public hearing here.
Gravel mining on St. Vrain Creek upstream of Longmont would likely increase the risk of flooding, both within the city and in surrounding areas downstream, which would completely defeat the purpose of the Resilient St. Vrain flood mitigation project that Longmont is currently undertaking. This 2014 conference paper by Anthony R. Ladson and Dean A. Judd explains the short and long-term risks of floodplain gravel mining, particularly the likelihood that such mining may alter the flow of flood water and change river channels. As stated in the paper:
A literature review found 37 examples where rivers had broken into gravel mines and the resulting river response had led to bed and bank erosion and threats to infrastructure.
A river is likely to jump tracks into a gravel pond because water follows the path of least resistance. When this happens, it increases the likelihood of damage. In 2013, this was perfectly illustrated when St. Vrain Creek diverted through the former gravel pits at Pella Crossing Open Space in Hygiene as described in this Times Call letter to the editor by Richard Cargill.
Please consider attending the public hearing on Wednesday, June 6 to voice your concerns regarding Martin Marietta’s gravel mining operation.