By Ronnie Schelby, USACEAugust 9, 2019
COCHITI LAKE, N.M. -- Biologists and natural resources managers with the U.S. Army Corps of Engineers, Albuquerque District, participated in a hands-on riparian construction workshop at the Corps of Engineers Cochiti Lake and Dam located north of Albuquerque, in Pena Blanca, February 26-27.
The workshop was a collaborative effort between members of USACE's Albuquerque District; the Pueblo de Cochiti Department of Natural Resources; the U.S. Army Engineer Research and Development Center, Environmental Laboratory. Members of the San Felipe and Santa Ana pueblos also participated.
"This workshop is part of an ongoing Corps-wide effort to address federally threatened and endangered species issues through proactive conservation activities," said Dr. Richard Fischer, research wildlife biologist, U.S. Army Engineer Research and Development Center Environmental Laboratory.
"Our objective is to introduce USACE, interested individuals, tribes, and agency partners to a number of deep-planting techniques to enhance, expand, and restore riparian areas," Fischer said.
Fischer and Dave Derrick, potomologist, River Research and Design, Inc. were the workshop instructors.
"One main purpose for the workshop is to introduce new planting methods that can be used in arid locations," Derrick said.
Cochiti Lake was selected because of the opportunities available to rehabilitate the shoreline with native species to not only help improve water quality but also to provide habitat for a wide range of riparian-dependent fauna.
"Through species diversity and planting locations we want to increase the understanding of what plants work where and what planting methods work best," Fischer said.
Cochiti Lake Staff cut and soaked dozens of live willow and cottonwood poles ahead of the workshop, in preparation for the participants to replant during the workshop. The staff focused on five specific plants that grow naturally around Cochiti Lake -- three varieties of cottonwood trees and two types of willows.
During the workshop, the participants continued cutting more poles, then transported all plantings to preselected locations within the Cochiti Lake area. These preselected areas had no vegetation.
Large trenches had been partially dug prior to the workshop. However, there was still some digging to be done.
Two styles of trenches were utilized -- the slit and heron foot. The slit trench is a basic rectangle shape, with the sides dug straight down. The heron foot trench, which resembles the shape of a heron's footprint, was more complicated to create and was accomplished using a backhoe.
"Time is wasted when a backhoe changes position. The operator spins and stabilizers have to be repositioned," Derrick said. "This method allows multiple digs from a single position and utilizes time to the max."
All of the trenches were excavated down to the water table. The poles were planted six feet down with one foot of spacing between the plants. Once in place, all plantings were backfilled with soil so that two-or three feet of the cutting extended above ground level. The poles were planted at varying distances from the water. This was scientifically calculated in order to see which plants thrived or failed.
"The restoration workshop demonstrated rapid techniques for establishing stands of riparian trees," said Michael Porter, fishery biologist, U.S. Army Corps of Engineers, Albuquerque District. "Understanding what works should support lower cost restoration that increases our capabilities."
Corps of Engineers Rangers working at the Cochiti Lake will be monitoring growth of the plantings, in order to determine which survive and thrive, and which do not.