Riparian Conservation Buffer and Open Space Acquisition

According to the Environmentally Responsible Planning section on the RSVP section of the city’s website, one of the goals of the RSVP is to “complete the project work in an environmentally sensitive manner.” One of the ways the city will achieve this goal is by planting “native-species trees, shrubs, and grasses” so as “to maintain and enhance natural wildlife habitat areas along the creek.”

Eleven tree species have been highlighted for planting as part of the RSVP project with 6 of these species being riparian species native to Colorado. Visualizations of the river corridor following completion of the RSVP show a few trees, presumably of these species, but the vast majority of vegetation shown is grass. Is there a map showing where these tree species will be planted?

Longmont’s Land Development Code states that the riparian setback for St. Vrain Creek is 150 feet as “measured from the outer edge of riparian vegetation, including the outer edge of the canopy edge of riparian trees and shrubs, or from the top of the bank when riparian vegetation is not present.” Given that the river channel has been widened and existing trees removed in order to pass more water within that widened channel, the 150 foot setback should start at the edge (or “bank”) of the new river channel and native trees, shrubs, and forbs planted in that area to provide as much habitat and screening from artificial lights, noise, and human disturbance as possible. If the setback is to now be measured from the average high-water mark, trees and shrubs should be planted starting at the edge of the high-water mark.

To maintain the 150 foot setback, the city should either purchase the 150 feet from property owners adjacent to the St. Vrain or pursue conservation easements with said property owners to designate a riparian conservation buffer in perpetuity. Due to the recent flush of interest in developing the St. Vrain river corridor, this area should be one of the highest priorities for open space acquisition.