Mission Reach Lone Star Erosion Repair Project
Collen James Brownlow, PE, CFM
San Antonio River Authority
San Antonio, Texas
Tami Norton, PE, CFM, PMP, ENV SP
Ecosystem Planning & Restoration
San Antonio, Texas
The San Antonio River Authority (River Authority), created in 1937, is one of many such active river authorities in the State of Texas. Its jurisdiction covers 3,658 square miles in Bexar, Wilson, Karnes and Goliad Counties. In San Antonio, Texas, the River Authority owns and operates the Mission Reach Park. The Mission Reach ecosystem restoration and recreation project has increased the quality, quantity and diversity of plants and animals (flora and fauna) along the eight miles of the San Antonio River Mission Reach area. The ecosystem restoration process will be accomplished over many years through several steps including construction on the river to reconfigure the channel and create improved aquatic habitat, reestablishing hundreds of acres of native grasses and wildflowers and finally the planting of over 20,000 native trees and shrubs. The culmination of these steps will result in the transformation of the river into a more natural state.
Following several major flashflood events from 2015-2018, sections of the Mission Reach bank along the San Antonio River were experiencing severe bank erosion. Approximately 220 ft of bank erosion was identified along the west bank of the San Antonio River adjacent to the former Lone Star Brewery. Using natural channel design (NCD) principals, the River Authority intended to restore the stream channel and riparian areas to a more natural condition using native materials and minimal structures to reduce existing maintenance costs for removing downstream sediment and repairing infrastructure.
To address the bank erosion, the River Authority proposed the installation of toe wood. In 2019, a design was completed which included hydraulic modeling. The HEC-RAS hydraulic model was used to model the proposed toe wood structure effect on the regulated 100-year water surface elevations. The design specified use of 60 trees for footer logs and root wads. The repair project was completed in early 2020. This presentation will focus on lessons learned during the planning and construction of this exciting project!
About Collen James Brownlow, PE, CFM
Collen Brownlow, PE, CFM
Mr. Brownlow joined the San Antonio River Authority in 2018 and has over 20 years of experience in civil and environmental engineering. At the River Authority, he provides engineering and management support to the Water Parks and Operations Department with emphasis on the Mission Reach and Parks in Wilson, Karnes, and Goliad County. His expertise includes stream restoration, natural channel design, environmental permitting and compliance.
About Tami Norton, PE, CFM, PMP, ENV SP
Ms. Norton joined EPR in 2016 and has over 20 years of experience as a water resources engineer. Her expertise includes natural and man-made waterway solutions through stream restoration and natural channel design, as well as hydrologic and hydraulic modeling, floodplain studies and watershed master planning. Her role at EPR includes developing and growing Water Resources Service capabilities for the firm, training staff, and serving as project manager and lead design engineer for numerous projects.