Being Prepared for El Niño

El Nino

Photo credit: Small House Building

Meteorologists have forecasted a strong El Niño event for the 2014-2015 rain year. It is always important to be ready for a high precipitation season due to the potential flooding, erosion, and damage that may occur. To reduce erosion and prevent storm damage to exposed hillsides or project facilities, Aspen Environmental Group recommends early planning and the deployment of Best Management Practices (BMPs) to prepare for the impending rain this fall and winter. Preparation may include cleaning out flood control facilities, conducting permitted maintenance within drainages on your property, and installation of BMPs to control erosion and limit impacts to water quality. To help stabilize soils and prevent erosion, vegetation removal should be limited or wood fiber hydraulic mulch should be used in disturbed areas until permanent vegetation is established. If performed early enough to allow for the establishment of vegetation, hydroseeding of disturbed areas may provide for soil stabilization when paired with appropriate soil binders.

When installing erosion control devices, be sure to consider the slope, soil conditions, and size of the area so the most effective BMPs are implemented. For example, silt fencing may be installed to act as a linear sediment barrier of permeable fabric, which works best when trenched and keyed into the slope. When properly installed, straw wattles or fiber rolls can also act as a linear sediment barrier when trenched and staked in place. Temporary sediment or desilting basins may be constructed to collect and filter sediment-laden runoff prior to discharging to upland areas. For larger waterways, check dams can be installed to reduce scour and channel erosion by reducing flow velocity and promoting the settling of sediments. Always remember that any work performed within or adjacent to creeks and drainages (including sediment basins and check dams) may require permits from the U.S. Army Corps of Engineers (USACE), State Water Resources Control Board (SWRQB), and the California Department of Fish and Wildlife (CDFW).

Even with soil stabilization techniques and BMPs, heavy rains can damage jurisdictional features (e.g., creeks, rivers, drainages, swales, etc.) and threaten the safety of permanent physical structures in these areas. Should this occur, emergency repair permits are available from the USACE and the CDFW. In most cases where immediate work is needed to protect life or property, the CDFW does not need to be notified prior to commencing work. However, CDFW must be notified within 14 days of the start of work activities. Remember that the USACE must issue authorization for emergency work in federal waters. To streamline the permit request, the USACE implements Regional General Permit (RGP) No. 63. RGP No. 63 has been set up to provide rapid response to requests for emergency work within “Waters of the United States.”

To find out more about how Aspen can help prepare your projects for the upcoming rainy season, contact Jared Varonin in Aspen’s Agoura Hills, CA office.