Trinity River

A River of Drought & Deluge

(Skip two sections to Snags and Sinews: Navigating the Trinity if you want to get straight to the canal fight.) 

Native Americans in North Texas called the river Arkikosa; in the south it was Daycoa. French explorers of the late 1600s termed it Riviere des Canoës, the River of Canoes. The Spanish deemed it La Santisima Trinidad, the Most Holy Trinity. Now it’s simply the Trinity, the only river in North Central Texas, the aquatic thread that ties the terrain together. Once a classic prairie river with broad basins, marshes, and sprawling meanders, modernity changed most of it forever. (2)

Then a somnolent river usually in no hurry to get anywhere, it spread out onto broad grassy floodplains and riparian forests with rain deluges, thinned to a trickle during summer heat, and disappeared during drought. The meandering river jumped its banks into sloughs where fish and amphibians spawn, their young protected from the river’s usual predators, and oozed through well-watered bottomland forests to create some of the state’s most remarkable natural diversity.

Now in North Central Texas it flows constantly, with more than half its flow comprising treated effluent from wastewater treatment plants. (3) In urban areas, massive and tall levees constrain the river, artificially straight and hidden from awareness. It disappears from public consciousness to become nothing but a blue line on a map.

The Trinity’s riverine boom-bust cycles have their wisdom. Silt deposits from floods nourish fecund grass in the bottoms in areas where the river is still free. Pecans and oaks grow huge, watered by periodic inundation. Deer thrive in the bottomland forests and doves feast on native grass seeds, all to naturalists’ and hunters’ delight.

But the Trinity’s broad, flat floodplains are often dry—tempting places to build and develop. Constrain the river within levees and—voila!—more land for developers, their profit underwritten by taxpayers. Except the river always wins, one way or another.

Formative Forks of the Trinity River—West, Clear, Elm, and East

The Trinity coalesces from four forks and many creeks in North Central Texas to form the longest river whose watershed is wholly contained inside Texas. It skirts East Texas as it carves a diagonal path to the Gulf, emptying at Trinity and Galveston Bays. It is the most populous river in Texas and provides 40% of Texans’ water. (4)

The rangy West Fork extends from southeast of Wichita Falls 145 miles to its confluence with the Elm Fork on the west side of Dallas. It trickles through arid terrain to be impounded in its first reservoir, Lake Bridgeport. Nearing the northwest edge of Fort Worth, it’s corralled again into Eagle Mountain Lake and the sprawling Lake Worth, a primary water source for the city.

The upper reaches of the other western fork, the Clear, form southwest of Wichita Falls, also serving as an aquatic lifeline to the dry west. Seemingly modest, a severe 1949 thunderstorm in its headwaters created a wave of water that flooded much of Fort Worth west of downtown, killing almost a dozen people and causing millions in damage. (5)

The West Fork joins the Clear northwest of downtown Fort Worth. The manicured and levee-constrained West snakes past the city core and Stockyards in a big bend and then takes a hard turn due east toward Arlington and Dallas.

The Elm Fork arises scant miles from the Oklahoma border northwest of Dallas, thwarted by the Red River bluffs. Gathering a tremendous amount of rainwater as it courses south, it becomes the core fork of the Trinity. It’s dammed to create two immense reservoirs, Lake Ray Roberts and Lewisville Lake, and then descends into Dallas.

The Clear and West Forks traverse the limestone expanse of the Western Cross Timbers and Fort Worth Prairie. The Elm’s headwaters lie in the sandy Eastern Cross Timbers. The forks merge in the dark clay soil of the Blackland Prairie. (6) The Trinity weaves North Central Texas’s ecoregions together, as does the 127-mile-long, nationally recognized Trinity River Paddling Trail.

The North Central Texas bedrock layers are at an incline, with the older, lower layers surfacing as you go west. The soft limestone of the eastern section, formed from an ancient marshy inland sea, is 60 million years old. Compare that to the hard fossiliferous limestone of the west, formed from ancient seashores, at over 250 million. (7) Rainfall in the northern half of Texas decreases one inch every 20 or so miles west of the Louisiana border. The Trinity’s main stem pulls in 35 to 40 inches annually, while the western headwaters might get 20 inches or less in a dry year. (8)

The Trinity headwaters and forks span vast breadths of rainfall, ecology, geology, and time.

Trinity River Main Stem, its East Fork Sidekick, and On To the Sea

The Trinity River comes into being when Elm and West Forks meet northwest of downtown Dallas.

Once a marshy confluence rich in aquatic wildlife, the 1908 flood changed that, swelling the river to more than half a mile wide, leaving eleven dead, and causing millions in damage. A massive channelization project ensued by the early twentieth century, straightening the river and moving it a half mile westward, much of it squeezed between gargantuan levees, out of sight, out of mind.

The conjoined Trinity squeezes past downtown in a half-mile-wide chasm of moed grass created by massive levees. Once freed of its levees, it sprawls into the 6000-acre Great Trinity Forest, the largest urban bottomland hardwood forest in the nation. The wet and wild environment enraptures with abundant birds and wildlife. Trees, some centuries old, grow tall and thick. Briar vines wind through a rampant understory. A grove of exceptional Texas buckeyes adorns a riverside spot.

Now fully a Blackland Prairie river, its banks’ dark, rich clay soil causes them to collapse, taking trees and dirt with them, making the “Little Muddy” a Trinity nickname. Some snags end up firmly mired in the muddy bottom. Others drift and form large log rafts and jams. The murky river ambles for 45 miles southeast of Dallas where it joins the final East Fork, a meek flow from northeast of McKinney. The East is impounded twice as Lavon Lake and Lake Ray Hubbard. Its flow thusly diminished, it eeks 20 miles to meet the Trinity.

South of the Trinity-East Fork confluence, (10) strong rains flush topsoil from farm and ranch fields, filling the river with silt, adding to the muddy melee, especially before soil conservation practices became more common in mid-1900s. The river grows shallow as it spreads in looping meanders through a grassy savannah floodplain, perfect for wildlife, tedious and treacherous for boats. (11)

The 700-mile-long Trinity ends its aquatic journey in the boggy terrain of Southeast Texas, swollen by nearly 60 inches of rain a year. (12) It gushes into the Gulf at Trinity Bay, a sidearm of Galveston Bay, where it nurtures a vast estuary. Looking at the bayside Trinity so wide and deep, it seemed to 1800s folks that navigation on the Trinity would be easy. And it was… for the first hundred or so miles.

Snags and Sinews: Navigating the Trinity

Getting close to population centers like Dallas and Fort Worth was a hard slog. Boats were forced to dodge a continual array of snags, or disembark and drag them aside. Rafts of floating logs were a continual danger. Spring rains swelling the river gained some relief for navigation. (13)

Navigation from North Texas to the Gulf seemed folly from the start. Three US Army Corps of Engineers (USACE) studies over a century starting in the mid-1800s decreed the river too shallow, drought-prone, and snag-strewn for navigation once out of rainy southeast Texas. Nor were there enough commodities to be shipped that would justify the immense cost of making it navigable. (14)

Undeterred, navigation boosters persisted, ever hopeful a subsequent study or twist of fate would justify their dreams. Starting in 1893, organizations set on commercializing the Trinity formed and disbanded. Citizens attended hearings, expressing skepticism and wondering why those benefitting from the canal were paying little of the costs. (15)

Nothing derailed water navigation more than the ascent of railroads which arrived in North Texas in 1873. (16) Canal operators in the Midwest were mortified. Dueling acts were passed in Congress, favoring one or the other. (17) Seven railroads serving Dallas constructed the massive Union Station terminal in 1916, locating it on a modest bluff that would have been a prime boat-docking location. (18)

Navigation to North Texas seemed doomed. Upon achieving a monopoly, railroad shipping rates soared. Navigation boosters seized the stranglehold to lobby even harder for river infrastructure underwriting. (19) Everybody loves the free market until it impacts them.

Despite being more popular with politicians than the public, navigation dreams not only soldiered on, they grew in scope. At the turn of the 1900s came the idea that Trinity navigation was possible if dozens of dams created a series of slack-water reservoirs, with locks enabling boats to change levels. It would require straightening the river, its meanders cast aside and filled in so a canal could slice through. Essentially erasing the river and destroying untold acres of bottomland. (20)

The federal government was lobbied, cajoled, and even threatened for funds by boosters. Millions were extracted for more studies, hoping for a result more to canal boosters’ liking. (21) Locks and dams got built and then abandoned, and river sections channelized, ever ignoring that snags and log rafts once cleared would simply be replaced. These follies cost many millions of tax dollars. (22) When pressed to contribute more funds, businesses benefitting from navigation became much less enthusiastic. (23)

Navigation dreams weathered various gut punches: World Wars I and II, the Korean War, and the Great Depression. Presidential administrations and political parties swung between vast infrastructure programs and austerity regimens. More than once the canal seemed down for the count. (24)

Eventually, federal funds stimulated by New Deal programs, especially for reservoir construction, aided the navigation cause. Now navigation infrastructure could be tied to flood control and water supplies—an upsell of epic proportions. (25) Unwise development in floodplains furthered calls for riparian flood controls. Bring on the levees, locks, and dams!