Far from the Mexican border and just outside one of Texas's major tourist destinations, with its popular nearby beach and bustling port, a string of shantytowns thrives.

Hidden behind acres of tall grain sorghum live some of the area's poorest residents. They bought the only piece of the American dream they could afford: a patch of land with no running water and no sewage treatment or wastewater service. Their homes are modest, made of wood or vinyl siding. Some live in shacks made of scrap metal or in dilapidated trailers. The spring rains bring massive flooding to these low-lying areas and with that, contamination, disease and disruption of life.

Known as colonias, these developments have existed for years along the border with Mexico. Now they have migrated north, attracting not only new immigrants but also second- and third-generation Mexican Americans, and whites and blacks unable to find affordable housing elsewhere.

Dozens of the unregulated, rural subdivisions have sprung up deep into Texas, near Corpus Christi and outside Austin, Houston, Beaumont, San Antonio and as far north as Dallas and Fort Worth. Officials say unscrupulous developers take advantage of weak county laws to subdivide land and sell the plots with inadequate, if any, improvements. Over the past decade, Texas lawmakers have passed tough regulations on colonias near the border. With the squalid developments spreading, lawmakers are turning their attention to the rest of the state.

"This is just like Guatemala or Africa," said Lionel Lopez, a retired Corpus Christi firefighter who organized the South Texas Colonia Initiative to bring attention to what he counts as 88 such developments in Nueces County. "You see kids with all kinds of sores on their little legs, and the dogs -- they don't even bark, and they have mange."

The cheap land -- lots can cost $30,000 to $40,000, with or without a structure -- look ideal to residents trying to escape a tough inner-city neighborhood or who cannot afford starter homes at $80,000 or $90,000 within the city limits. "Through throwing up a substandard subdivision, you can offer a segment of our society their dream," said Donald Lee, executive director of the Texas Conference of Urban Counties. "Unfortunately, what you're not telling them, and they oftentimes don't realize, is that they're buying into a nightmare."

The residents of the colonia known as Tierra Grande, eight miles southwest of Corpus Christi, have survived their latest nightmare: two months of heavy rains that caused massive flooding. The development sits in a flood plain, atop a maze of underground ethylene, methanol and natural gas pipelines that feed into Corpus Christi's nearby refineries. The development has no drainage system, and the homes have only septic tanks to handle solid waste. So bad was the recent flooding that septic tanks overflowed, and human waste saturated the floodwaters inside and outside the ramshackle houses. Snakes slithered into homes, and huge water beetles that look like leeches crawled out of the flooded vegetation and into residents' damp mattresses. Parents carried their children on flooded roads out to a county highway to catch the school bus because the vehicle could not enter the community. Mail was not delivered for a month.

Furniture, cars and trucks were ruined. Wells, which many residents depend on for cooking, washing and bathing, were tested and found to have three times the amount of acceptable E. coli bacteria for human contact and an unacceptable level of dissolved solids for human consumption, said Rick Hay, a research associate with the Center for Water Supply Studies at Texas A&M University at Corpus Christi. The roads were rutted, the mosquitoes flourished, and some of the ditches along the roads held opaque, larvae-laden water a month after the last rains. A few years ago, the several hundred residents of Tierra Grande experienced the same type of flooding.

"If I had money to move to Corpus Christi, I'd be living over there," said Zulema Tovar, 40, as she sat outside her corrugated tin house, holding her 5-month-old daughter, Yesenia. Tovar has lived in Tierra Grande six years. Her two daughters contracted bronchitis during the worst of the flooding, and her 24-year-old nephew was hospitalized after a leg cut became infected from the contaminated water around their home. Other relatives suffered diarrhea and fever. Several of Tovar's toenails softened and fell off. She believes that happened because of the contaminated floodwater she had to walk through for days.

"Nobody ever told us anything about anything, about the flooding," Tovar said. "I guess people would say [about us], 'They should have known better.' But us being poor Mexicans, too, we're trying to do the best we can."

Texas legislators who represent the areas north of the border where the colonias are growing say they want to stop development of the subdivisions and provide state aid to residents.

"You've got people living in these Third-World conditions. . . . It is a serious problem in urban counties," said state Rep. Dora Olivo, a Democrat whose district just outside Houston, which includes four colonias, overlaps with the congressional district represented by House Majority Leader Tom DeLay (R-Tex.). "People move out there because it's too expensive to live in the city, into areas that aren't regulated. . . . Unscrupulous developers come in and do the wrong thing. But how do we prevent proliferation of colonias? It's an expensive proposition."

Today, an estimated 1 million Texans live in these unregulated subdivisions that have sprung up far from the border and lack adequate water or wastewater service, according to the Texas Water Development Board. The cost for providing such services would be huge.

"The total needs are $1.82 billion to bring water . . . and there's $1.95 billion in wastewater needs," said Jonathan Steinberg, the board's deputy counsel. "We've got a problem here."

Since the late 1980s, the Texas Legislature and various state agencies have focused on border colonias, passing strict state laws at the end of the last decade to prohibit further development. Border counties and counties 50 miles inland from the border were given the power to require developers to provide water and wastewater services in new residential subdivisions. In 2001 Texas voters passed a $175 million bond issue to improve existing colonia conditions by funding water, sewage and drainage systems. Millions in federal funds also were earmarked to help.

More recently, the legislature began focusing on the "urban colonias" by targeting certain urban counties and their neighboring counties and giving them limited power to regulate rural subdivisions. However, counties still have no zoning authority.

These urban counties now "have a vague authority to ensure that moral, orderly and healthful development -- that's the key phrase -- occurs," said Jeff Barton, a land-use and planning consultant who is a former commissioner in Hays County, just south of Austin. Barton was a commissioner in 1998 when Hays County had to approve a special budget appropriation to provide emergency hepatitis shots to hundreds of residents in a substandard rural subdivision called Green Pastures. The residents' septic tanks had failed. During heavy rains, the houses and dirt roads were flooded with human waste that children and adults waded through daily -- 22 miles south of the state capitol. President Bush, who was governor of Texas at the time, never visited a colonia but supported and signed a dozen bills to help them.

Barton said counties, a weak form of government as prescribed in the Texas Constitution of 1870, are not accustomed to exercising authority over development and land use.

"They've been very skeptical and very cautious and maybe even overly cautious about moving into this territory," he said. "There is some room for counties to be aggressive and more proactive in addressing growth issues. . . . We are a different state than we were 150 years ago, and it's time that we recognize that."

Lionel Lopez of the South Texas Colonia Initiative points to larvae-laden floodwater in a ditch. "This is just like Guatemala or Africa," he says.A dilapidated trailer houses nine people in a colonia, or unregulated subdivision, called Tierra Grande in Nueces County.