WESLACO, Texas _ More than 40 Texas farmers, ranchers and irrigation districts are gearing up to take their long-standing water war with Mexico to the next level, which in this case is a Canadian judge.Texas Comptroller Susan Combs came to the Rio Grande Valley for a pep talk Tuesday, to reinvigorate farmers who have been fighting for three years and running up legal bills of almost $500,000."You roll over now and you won't be in good shape," Combs told a room full of farmers and ranchers.In 2004, the farmers and ranchers sued Mexico for $500 million, arguing that their southern neighbor had shorted them on Rio Grande water from 1992 to 2002 in violation of a 1944 treaty.In June, a tribunal operating under the North American Free Trade Agreement decided it did not have jurisdiction, stalling the case before it got started.Most frustrating to the landowners was that the U.S. State Department intervened at the last moment and sided with Mexico."When they did that, it really just hit you in the stomach," said Joe Barrera, general manager of the Brownsville Irrigation District. "We've kind of lost that spark that we had at the beginning."We've got to get it back," he said.The groups plan to ask a Canadian judge to decide March 25 whether the tribunal erred and deprived the farmers of a fair hearing. The case goes to Canada because both sides agreed in arbitration that if an issue arose they would go to a neutral location.Combs urged the farmers, a mixture of large and small operators, to contact their state and federal legislators in hopes of keeping the State Department on the sidelines or to bring the it over to their side.State Department spokeswoman Joanne Moore said no one was available Tuesday to comment on the dispute.The farmers, many of whom sit on irrigation district boards, worry about letting the water issue pass without consequence for Mexico."If Mexico doesn't pay any penalty, it's easier for them to do it again," said Ray Pruitt, president of Texas Citrus Mutual.A call to the Mexican Consulate in McAllen late Tuesday was not immediately returned."This is their water," said Nancie Marzulla, a Washington, D.C.-based attorney handling the farmers' case. "This is a water fight."The farmers can sue Mexico under the NAFTA rules because they have property — water — in Mexico that Mexico appropriated, Marzulla said.NAFTA is the only way the farmers can seek redress, because the 1944 treaty between the United States and Mexico has no provisions for individuals suing a country.The state will file a brief supporting the farmers with the Canadian court. A Canadian attorney, retained for $10,000, is handling the paperwork.Texas is joining the fight because if it hurts the farmers, it hurts the state economy, Combs said."You must call (legislators). You must try everything," Combs told the farmers. "This is really important to the state. It's important to the valley."