October 2024

Five Streams Will Spring to Life this Fall

Upper Trinity’s contractors are finishing up construction on five new streams near future Lake Ralph Hall, which will flow into the North Sulphur River. The newly connected tributary streams will naturally begin to flow with rainwater this fall, bringing life back to areas impacted for decades by severe erosion and loss of habitat.

Reviving Natural Waterways

Texas Mitigation Solutions (TMS), a joint venture between Ecosystem Investment Partners and Mitigation Resources of North America, led the stream mitigation project. They restored over 32,000 linear feet (just over six miles) of streams below the lake’s Leon Hurse Dam. These streams are connected to the North Sulphur River and were disrupted when the river was channelized in the 1920s. While the channelized North Sulphur River protected nearby farmland from flooding, the changes caused erosion and destruction of quality habitat and multiple state highway bridges over the decades. Restoring the tributaries of the river to their natural, curved paths helps provide previously lost habitat.

How do you build a stream? Texas Mitigation Solutions (TMS) started by working with its design engineer Beaver Creek Hydrology to map the original location of the North Sulphur River tributaries. Then they designed improved paths to reconnect the former North Sulphur River with four supporting tributaries that match their original locations as much as possible. “I’d say 80% of length is within the existing floodplain,” said TMS’ Site Construction Manager Dustin Fitzgerald.

Next, crews dug out the pathway for each tributary, ensuring each has sufficient bends to slow down the flow of water.

“Our team used bulldozers and track hoes to cut the channel,” Fitzgerald explained. Afterwards, they removed earth to create “a space for each tributary’s floodplain,” or the land area that floods naturally during heavy rainfall. The construction teams added live staked willows, biodegradable matting and native grasses to help establish the streams and provide habitat for local wildlife. Once they’re filled with water, the streams will range from around 1.5-3 feet deep and 8-10 feet wide.

To prevent the new riverbeds from eroding, crew members also incorporated “gravel” and “woody riffles”—gravel and logs laid across the stream to slow the flow of water. These protect the stream banks and raise the water table, promoting a healthier ecosystem. They also create pools of water, a habitat for frogs and bugs.

“It’s incredible to see these waterways being returned to their natural state,” said Nolan Drewery, Texas Mitigation Solutions Construction Supervisor. “This work will bring back river pool habitats and improve water quality immediately downstream.”

Overcoming Challenges

A particularly challenging part of the project was the intricate process of connecting new tributaries to the main river—all during an especially rainy spring. “We had to tie in streams to a main channel that was 18 to 20 feet deeper,” explained Fitzgerald. “We also had to dig these streams in very wet conditions. But now that everything is tied in, we’re just waiting for the rain to come and naturally fill the new streams.”

Looking Ahead

This fall and winter, TMS and subcontractors will continue to plant grasses and 40,000 native trees (20 different species including sycamore and various kinds of oak). These plantings will improve soil health and further stabilize the stream banks. Then the team will transition to monitoring the site to ensure its success. Over the next seven years, team members will use advanced stream assessment techniques to make sure the restored streams and plants are achieving key ecological goals.

As Lake Ralph Hall’s stream mitigation efforts wrap up, the project is set to provide long-term environmental benefits for North Texas.

“It’s been a rewarding project,” Fitzgerald noted. “Seeing these streams come back to life and knowing the positive impact it will have on the surrounding environment makes all the hard work worth it.”

Archeologic and Palaeontologic Protocols During Construction of Lake Ralph Hall

For the construction of Lake Ralph Hall in Fannin County, Upper Trinity Regional Water District (UTRWD) operates under a permit with both the US Army Corps of Engineers (USACE) and the Texas Historical Commission (THC). The permit requires careful handling and study of artifacts, fossils and archeological items. All contractors working on the Lake Ralph Hall job sites are trained on standard operating procedures for when a suspected artifact is detected.

UTRWD has contacted AR Consultants (ARC) to manage and execute handling, studying and recording artifacts and fossils found onsite. ARC is a highly regarded expert in archeology and has worked on numerous sites in Texas and nationally. To date, hundreds of archeologists have conducted investigations within Lake Ralph Hall. Crews average about 50 in the field at a time. Findings will be compiled into final reports in compliance with the Texas Administrative Code Chapter 26. Redacted versions protecting site locations will be available to the public once the reports are filed with USACE/THC. Artifacts and records related to these studies will be permanently curated at the Center for Archaeological Studies at Texas State University in San Marcos according to the Texas Administrative Code Chapter.

Since the beginning of construction on Lake Ralph Hall, UTRWD has worked with the Perot Museum to identify, extract and/or study significant fossil finds. This includes the 2022 discovery of a Tylosaurus on a section of the North Sulphur River owned by UTRWD (see image below - courtesy of the Perot Museum). UTRWD worked with Perot Museum paleontologists to extract the specimen for further study at the museum.

To continue allowing public fossil hunting in the North Sulphur River during lake construction, UTWRD constructed a temporary Ladonia Fossil Park. Once Lake Ralph Hall is completed, a new, permanent fossil park will be established downstream of the lake’s dam. The new access point will be at a different river location and provide opportunities for additional and untapped fossil discoveries. Learn more.

Sharing the Progress

Several members from the Texas Water Development Board and Texas Water Conservation Association visited Lake Ralph Hall. They saw firsthand the significant recent progress made on the dam, spillway and other components (see photos below).