Two years ago, there were no zebra mussels in Lake Texoma.
Today, there are millions.
In a lake, zebra mussels are like zombies. They crowd out fish populations by eating all their food, and they can never be killed.
That's why federal rules prevent spreading the mollusks from infested lakes to healthy ones.
Right now, Texoma is the only infested lake in Texas.
"My own gut feeling is, you don't want to know what's going to happen," said University of Texas at Arlington zebra mussel expert Robert McMahon. "The best thing to do — and the cheapest thing you can do, frankly — is to contain them where they are."
In 2009, Bruce Hysmith, a biologist with Texas Parks and Wildlife, made the first public report of a zebra mussel discovered in Lake Texoma.
"One zebra mussel, on one cable, on one boathouse," he recalled. On April 15, 2009, Hysmith gave written notice of his find to several state and federal agencies.
But a News 8 investigation found no written notification was provided to the most important agency: The North Texas Municipal Water District.
What's so important about them? They were pumping huge volumes of water from Texoma to Lake Lavon.
When was NTMWD first notified?
"It was in late July of 2009," said Mike Rickman, assistant general manger of the water district.
E-mail records obtained by News 8 show the precise date was July 23 — three months after zebra mussels were discovered in Lake Texoma.
In that time frame, the water utility pumped more than 3.7 billion gallons of water out of Texoma — where zebra mussels were discovered — and into Lavon, where there were none.
An e-mail obtained by News 8 shows Hysmith also called the water district, but he "could not get past the receptionist."
"Basically," Hysmith said, "they appear not to be interested."
Hysmith said informing a receptionist about a serious environmental threat constitutes adequate notice, but he said he also followed up with an e-mail.
News 8 requested a copy of that e-mail, but neither TPWD or NTMWD has a record of such a message.
"I cannot help it if those people are so enshrouded in secrecy that they're not going listen to somebody else," Hysmith said. "Did they not believe it? Did they think it was hoax? Did they think it was a terroristic plot? Who knows."
When the top leadership at NTMWD was finally notified three months later, it stopped pumping water from Texoma to Lavon. It has not resumed since, complicating problems during the North Texas drought.
What would've happened if they had been notified three months earlier? "We probably would've taken some action as far as stopping the pumping," Rickman said.
So far, there's no proof zebra mussels made it to Lavon. "However, that doesn't mean it can't happen," said the UT-Arlington researcher McMahon.
Everyone — including Texas and Parks and Wildlife — is hoping it won't, and that those three lost months and billions of gallons of pumped water didn't help spread a problem that has no solution.