2023 Yearbook of Engineering Achievement: Water/Stormwater

Bois d’Arc Lake Program | Alpha Testing, a UES company

Fannin County, Texas

Project Team: Ken Combs, CET, Executive Vice President & Principal in Charge Eric Cleveland, PE, Associate & Materials Testing Engineer Josh Hall, PE, Project Manager (Dam, Raw Water Pipeline) Henok Abebe, Project Manager (Leonard WTP)

Start Date: 1 May 2018

Completion Date: 30 April 2023

Accreditation and Awards: 2023 Project of the Year By American Public Works Association Texas Chapter

Background:  Bois d’Arc is a $1.6 billion water supply program that is the first major water reservoir built in Texas in nearly 30 years and is designed to meet the water needs of the area’s growing population of more than two million people in 80 communities.  Alpha Testing, a UES company, was chosen by the North Texas Municipal Water District (NTMWD) to provide quality control/construction materials testing services to multiple project teams.  Bois d’Arc Lake will span 16,641 acres. The dam is two miles long and 90-feet tall, with a 110-foot-tall intake tower. It collects water and filters through the Raw Water Pipeline to the Leonard WTP. The 90-inch diameter Raw Water Pipeline travels 35 miles from the dam, delivering untreated water to the treatment plant. The Leonard WTP includes six pumps to filter and treat 90 MGD of water to then go through the Treated Water Pipeline.  Alpha Testing utilized two on-site laboratories and up to 15 full-time field and laboratory personnel to serve the Bois d’Arc lake project that will span 16,641 acres.

Impact:  Bois d’Arc Lake will be a tourist and residential destination for numerous outdoor recreational outdoor activities including fishing, boating, and time spent by the water while also serving as a critical water source as demand grows for a rapidly expanding population of North Texans.  Bois d’Arc Lake will provide water services for nearly 80 communities just outside of the Dallas-Fort Worth Metroplex–an area that is expected to double in population by 2050 according to the NTMWD.  The Leonard Water Treatment Plant (WTP) will treat water from Bois d’Arc Lake to meet federal and state standards, which is necessary when delivering water to the northern portion of the NTMWD’s service area.

Technical Aspects:

• Fully equipped onsite concrete and soil laboratories dedicated to the project and staffed by certified engineering technicians
• Development of GIS-based program to track testing results in real time, particularly for the reservoir dam
• AWS-certified welding inspectors responsible for inspecting weld quality (both pipe and structural welds), structural inspections, and workmanship

Buescher State Park Dam | Halff

Smithville, Texas

Project Team: Halff

Start Date: 2 August 2019

Completion Date: 18 August 2023

Background: Remnants from Hurricane Harvey in 2017 hovered over Central Texas for several days, creating flooding throughout the region that damaged structures such as the historic Buescher State Park Dam.  The dam’s structural integrity was threatened as several feet of material eroded away during the rain event, and the Texas Parks and Wildlife Department (TPWD) needed to find an immediate solution that would preserve the historic structure and protect a critical economic resource.  Halff was contracted to perform emergency repairs that stabilized the dam and prevented a breach.  After the emergency repair and understanding the importance of a more permanent solution, TPWD again contracted Halff to implement detailed construction plans, specifications, and cost estimates for rehabilitating the dam to comply with current regulations, which included improvements to the dam’s embankment and principal spillway.  The newly designed Buescher State Park Dam retains historical homages to the original structure, such as the native red sandstone, while offering a structure that meets current standards and can preserve the economic importance of the park for years to come. 

Impact: By finding a permanent solution for the dam, TPWD has been able to reopen its recreation program, which will ultimately help lift the local economies of Smithville and Bastrop.  Halff worked with the U.S. Army Corps of Engineers (USACE) to improve stream functionality with a riffle-pool sequence. Once fully established, this will provide an additional habitat for the native amphibians and birds within the park.   Halff also developed an innovative approach to reduce potential impacts to endangered species, particularly the Houston toad, which included measures like taking a traditional silt fence and repurposing it to develop toad exclusion fencing.  Design enhancements for the new structure included installing a sharp-crested, straight drop principal spillway, training/retraining walls, grading, native stone rock riprap and stream enhancements.

Technical Aspects:

• Spillway improvement features more than 340-feet of retaining walls, a stifling basin, and a 200-foot sharp crested weir and spillway chute
• Dam design and dam breach analysis

San Fernando Regional Park Infiltration Project | CWE

San Fernando, California

Project Team: City of San Fernando, CWE, Ortiz Enterprises, Inc., C Below, Inc., Terracon Consultants, Inc., Linkture Corporation

Start Date: 1 December 2018

Completion Date: 4 October 2023

Background: The City of San Fernando (City) is implementing the San Fernando Regional Park Infiltration Project (Project). The Project was identified in the Upper Los Angeles River (ULAR) Enhanced Watershed Management Program (EWMP) Plan as a priority regional project and will assist the ULAR group in addressing applicable Total Maximum Daily Loads (TMDLs) and water quality priorities.  The primary goals of the Project were to improve water quality while providing multiple benefits. The Project will divert and capture wet- and dry-weather runoff from over 940 acres, effectively reducing pollutant loads that would otherwise enter Pacoima Wash and the Los Angeles River. The captured runoff will be pretreated and then discharged into a subsurface storage system that will facilitate infiltration at the San Fernando Regional Park, resulting in groundwater recharge. In addition to recharge and water quality benefits, the Project will have additional benefits including flood control benefits and public outreach benefits (outreach events and permanent signage).

Impact: The 9.5-acre park includes the San Fernando Regional Pool and Community Center, a children’s play area, and athletic fields. Surrounded by urban development, the park is bound by a Metropolitan Transit Authority (MTA) railway to the west along First Street, industrial parks on the south and east corners, and medium-density housing to the north on Park Avenue.  The Project ensures continued use of San Fernando Recreation Park by the DAC seeking respite from the stress of a highly urbanized environment. The Project includes the following improvements: establishment of landscapes around the subsurface storage system, restoration of the baseball field, restoration of the existing irrigation system, replacement and restoration of light poles and electrical conduit, and restoration of streets and sidewalks. The Project enhances the community’s quality of life by encouraging recreational activities that help maintain a healthy community.

Technical Aspects:

• Diversion and pre-treatment of runoff from three local storm drains into a subsurface storage system for infiltration
• Subsurface storage system footprint of 15.6 addition acre-feet, resulting in a single-storm capture volume of 25-acre feet
• Pretreated flows conveyed through a gate valve