By Kristen Tribe

In the 1800s, saltcedar was brought to the United States from Eurasia and planted as an ornamental. " . . . then in the late 1800s the government started using it to combat erosion," says Dr. Charles Hart, Extension range specialist, Fort Stockton, Texas. "The whole purpose was to stabilize stream banks . . . and quite frankly, it has done a heck of a job."

Two hundred years later it has infested rivers and streams across the western United States, slowing down their flow and dipping into regional water supplies. Hart has led a saltcedar eradication program along the Pecos River for the past five years that has become a blueprint for similar projects around the state and the rest of the country.

"The No. 1 reason so much emphasis has been put on saltcedar lately is because it is such a heavy water user," says Hart. Its water use has been compared to that of a large cottonwood tree, and in perfect conditions, it can pull 200 gallons from the ground in one day.

The Pecos is not a naturally flowing river, but an irrigation delivery system for water that is released from Red Bluff Reservoir to the seven water districts below it. According to the Red Bluff historical release and delivery data, from 1993 until 1997, Red Bluff released an average of more than 68,000 acre feet of water per year, but on average, just more than 30,000 acre feet were delivered.

What happened to the other almost 38,000 acre feet?

Hart says some of that disappeared in the aquifer or evaporated, but he feels like saltcedar consumed a significant amount.

Dr. Allan McGinty, Extension range specialist, San Angelo, Texas, half-jokingly says this is the only plant that’s absolutely evil. He’s working to establish an eradication program on the Colorado River.

The Colorado was site for the first shallow groundwater wells to determine how much water saltcedar takes from aquifers over time. The wells are drilled in the aquifer and data loggers take a reading of the groundwater levels every second, revealing daily fluctuations in the water table.

Hart explains that while the saltcedar is transpiring during the day, the water level goes down, but at night when it quits transpiring, the aquifer recharges. He says the aquifer level doesn’t change when the saltcedar is dormant, but when it’s green, the water level is up and down.

Saltcedars can’t survive for long if they’re too far from a water source, like rivers, streams or springs. The roots will go down until they hit water and then they go lateral. Hart says they’ve grubbed plants out of the ground that have roots 40- or 50-feet deep and some only one-foot deep; it just depends on how deep they have to go to find water.

Besides using water by the gallons, saltcedar also increases the salinity of the streams and rivers it infests. It’s capable of living in salty conditions and it pulls salty water up through its roots and excretes it through its leaves.

These leaves then fall into the water increasing salinity levels. The plant also drips the salt onto the ground, creating perfect conditions for itself while killing all other plants around it.

"We’re trying to document if by controlling saltcedar, we’re reducing salinity," Hart says.

He explains that before they started treatment, they took samples from 10 different sites between Red Bluff and Girvin, the last place where the water is used for irrigation. From the time the water was released until it reached its final destination, the salinity had doubled.

Following treatments, the salinity was the same at Red Bluff as at Girvin, which could be related to the eradication of saltcedar.

"We can’t say conclusively that we’ve reduced the salinity, but it’s sure indicating that initially," Hart says. He explains that the water level at Red Bluff was down this year, increasing the initial salinity level, but it had not increased when it was tested at Girvin.

The Red Bluff Water and Power Control District recognized the problems saltcedar was causing along the Pecos and representatives approached Texas Cooperative Extension about beginning an eradication program. Along with its seven supporting water districts, they put half a million dollars toward the project.

The Texas Department of Agriculture, Natural Resource Conservation Service and Upper Pecos SWCD all worked along with the Cooperative Extension to get the project started.

Before a tree could be touched, Hart and his charges had to get a new label for Arsenal® because the herbicide wasn’t originally designated for rangeland or aquatic use. With a lot of help from TDA, the Environmental Protection Agency eventually granted them the permit after two years.

The new label allows them to treat saltcedar but only in certain counties with very specific stipulations regarding endangered species on other streams and rivers. Luckily, there were no endangered species in the areas that needed to be sprayed along the Pecos.

Hart says the saltcedar can be treated from the beginning of August until mid-October, depending on the weather. For the past three years, they’ve applied the herbicide in September, and it’s done with a helicopter.

A helicopter is more expensive to operate than an airplane, but Hart explains that a helicopter does a better job since they’re working along the riverbanks. From the air, the river resembles a snake about to coil up, and it’s easier for a helicopter to follow its path.

A plane would have to bank hard to make the turns, throwing herbicide off target, but a helicopter can go slower, remaining almost level. There is almost no drift, and the swath width can be changed in the air from 45 feet to 30 feet and down to 15 feet, depending on how far the saltcedar stretches from the bank.

Although saltcedar grows 15 to 150 feet from the banks of the river, they treated no more than 90 feet on either side in the first year to try to get farther down the river with the money they had.

In 2001, the legislature agreed to give the project $1 million, which allowed them to go back and clean up beyond the 90 feet that they couldn’t spray before and go farther down the river. To date, they’ve treated about 120 river miles (3 river miles equals about 1 linear mile) and about 3,000 acres.

This treatment process costs about $190 an acre. This may seem alarmingly high, but Hart says you have to consider how many acre feet of water it can release.

For example, mesquite only costs about $25 an acre to spray, but eradicating it doesn’t release much water.

Mesquite gives the illusion that it "takes water" because it’s often the only thing left living in dry conditions. But in reality, it can just survive much harsher conditions and make more efficient use of the water it does receive.

On the other hand, saltcedar pulls so much water out of the ground daily that naturally, its eradication would prevent the loss of significant amounts of water.

"Ultimately, you’d like to clean up the basin and get rid of all the saltcedar. If you could get rid of it all, you could get rid of it for a while. Then it would take seeds from another source to reinfest it," Hart explains.

Every year each tree releases millions of seeds. It’s an issue of quantity versus quality. These seeds aren’t viable for a long time, but they can float and often go downriver and establish themselves along the banks.

Sometimes the seeds become embedded in the mud, and as animals come to drink, the mud sticks to their hooves, feet or paws. Wherever they knock the mud off, the seeds try to take root.

The seeds must have three weeks of totally saturated conditions though, and if they don’t find the right conditions within a year, then the seed dies.

"This is the only thing that has kept this plant from taking over the world," Hart says with a laugh.

Unfortunately, there are still two seed sources within an already-sprayed area of the Pecos. Hart says that every landowner has to sign an easement allowing them to spray the saltcedar and allowing them access for 10 years for maintenance. Although they’ve gotten the signatures of almost 600 landowners the past three years, two landowners have refused.

The two sites could potentially reinfest some of the river.

Saltcedar in New Mexico is also a threat to the water supply of the Pecos because seeds could get into the Texas river system, and it’s consuming a lot of water in New Mexico.

Due to saltcedar problems and the drought, New Mexico hasn’t been able to release much water into Red Bluff the last few years, and Red Bluff won’t be able to release any water to its districts in 2002, unless it gets some water from New Mexico.

Hart says they have annual data from Red Bluff from the 1950s and ’60s, and there was never a time when they didn’t release any water. Besides rare rainfall, this is the only source of watar many farmers and ranchers have along the Pecos.

Although New Mexico wants to start spraying saltcedar, they have to get a new label approved before they can go forward. Years ago, they did a lot of the initial research with Arsenal® and some of the first treatments. At that time, people began questioning its safety for aquatic regions, so they decided to leave a 50-foot buffer along the river.

They treated large flood plains, but the trees left along the river have kept the population viable. They are currently working to get the new label and more funding to pursue the project again.

Hart says the goal has gone beyond just getting more water in the Pecos to putting more water in the Rio Grande and eventually, Lake Amistad. In 2002, the initial phase of treatment will be complete on the Pecos and the maintenance phase will begin in 2003.

Maintenance could include spot spraying or going downriver on an airboat to treat seedlings.

In the meantime, Hart is also trying to start a treatment program on the Rio Grande. This is the first time in documented history that the Rio Grande has quit flowing, and it’s due in part to saltcedar, along with the drought in Texas, New Mexico and Mexico. Hart estimates that it will take $1.5 million to complete the Pecos project, which means it will probably take $5 or $6 million to treat the entire Rio Grande.

"There is no better place to put a buck than saltcedar control," says Dr. McGinty. "You get a lot more for your money than from any other woody plant."

McGinty has put together a task force and has been working for the last year to establish a treatment program on the Colorado River. He says saltcedar has infested 15,000 acres stretching from below Lake Ivy to above Lake Thomas, and treatment could release up to 60,000 acre feet of water.

Their energy has been focused on removing a restriction from the new label that prohibits spraying within two miles of the Colorado in Runnels, Coke or Mitchell counties to protect the Texas poppymallow, which doesn’t grow on the same sites as saltcedar, anyway.

McGinty thinks they are close to getting the restriction lifted, but they still face the challenge of funding. He fears if the saltcedar isn’t treated it could infest areas like Lake Travis, turning the banks into a jungle. When water levels were down, he saw saltcedar on Lake Buchanan two summers ago, and although the water levels have returned to normal, killing all those plants, he says he expects to see more saltcedar again along those banks in a year or so.

Saltcedar is just one factor that plays into the water issues of Texas, but its eradication could release more water than any other brush control program before.