Investigations into the flooding of New Orleans after Hurricane Katrina have focused on three main breaches of the city's levees -- and whether those defenses were poorly designed or built by an underfunded U.S. Army Corps of Engineers.

But there is growing evidence the New Orleans flood-control system sprang leaks in countless other locations around the city. Even if no levees had collapsed, parts of New Orleans still would have flooded, engineering reports indicate.

Engineers and others now say substantial blame for some of those failures lies with the ineffectual patchwork of agencies overseeing the system. A big part of the problem is a colorful relic of 19th-century Louisiana: the local "levee districts" that own and maintain most of the levees and floodwalls. Held up as an essential defense against floods, they also became vehicles for government contracts and political patronage, critics say.

The Orleans Levee District -- responsible for most flood control in the city and armed with a $40 million annual budget and nearly 300 employees -- had branched out over the years to build parks, marinas, a cash-strapped airport and a dock it leased to a casino gambling boat. Critics and some former board members say the board had lost sight of its original mission.

When Katrina arrived on Aug. 29, the first waters to enter New Orleans came through an Orleans district floodgate damaged nearly a year earlier, at a railroad crossing along the Industrial Canal. The $427,000 repair of the heavy steel gate -- normally left open to allow trains to pass but slammed shut when storms approached -- had been bogged down by bureaucratic delays and squabbling between the levee board and the railroad.

Water also breached in several locations where different agencies built floodwalls or levees with different heights, or used materials that weren't effectively connected. At one pumping station, where at least three agencies potentially had jurisdiction, a concrete flood wall connected to an earthen levee that was much lower. Katrina's waters gushed over the shorter levee -- rendering the larger structure useless, engineers say. Elsewhere, water poured over levees where local agencies had responded ineffectually to warnings that the embankments had sunk several feet lower than their original design.

"It was not always clear which agency had responsibilities for what ... parts of the system," concludes a report issued this month by a team funded by the National Science Foundation, which sent engineers to investigate the New Orleans flood. "Breakdowns" within the organizations and their failure to work together made matters worse, the report says.

A loose network of about half a dozen levee districts and other local agencies own most of the floodwalls, earthen embankments and pumping systems built to keep the Mississippi River and hurricane-driven tidal surges from swamping New Orleans and surrounding areas. Each board, appointed by the Louisiana governor and local elected officials, oversees a district representing all or part of a parish and has broad power to collect taxes or sell bonds to pay for flood-control projects.

The board of each district typically pays 30 percent of the cost of levee projects undertaken by the Army Corps and oversees the daily operations of its chunk of the system. The federal government funds the majority of the construction costs. The sewer and water board runs the pumps that drain the low-lying city of water. Railroads, private landowners and state agencies, such as the New Orleans port commission, also must be factored into the flood-control system.

The Orleans Levee District today controls 101 miles of hurricane levees with 127 floodgates, as well as 28 miles of Mississippi River levees with 76 floodgates. But neither the Orleans board nor any other entity has final authority or accountability for coordinating the various flood-defense systems. The Army Corps built most of the current levees using mostly federal funds. But it must seek funding and cooperation from local agencies anytime it needs to shore up or do other work on the levees.

Since Katrina, levee-board leaders and their allies in the Louisiana Legislature have insisted that they bear no blame for the hurricane flooding. Many point fingers at the Corps for any flaws in the system and at Congress for failing to provide funds. Efforts to change the levee-board system itself have been consistently thwarted. Just last week, the state House of Representatives let die a measure that would have reorganized key levee boards into a regional authority with clear command of the system.

With backing from the Legislature, the Orleans board branched out into areas only tangentially related to flood control. "We never talked about levees," recalls Peggy Wilson, who served on the Orleans levee board in 2001 and 2002.

During the year before Katrina, the Orleans board spent considerable time discussing the commuter airport it owns, modifying its lease with a floating casino and reviving a proposal to build a $280 million man-made island and fishing piers in Lake Pontchartrain.

Meanwhile, the Army Corps repeatedly warned local officials over the past two years that long stretches in the 350-mile levee system were sinking into the region's soft soil. In some cases, they were already as much as 3 feet lower than when they were originally built. The Corps said the levees urgently needed to be "lifted" but that it had no money to perform the work.

Orleans and other levee districts responded mostly by sending letters to Louisiana congressional delegates asking for more federal funding for the Corps. When Katrina's wave plowed into sinking levees and embankments east of the city along Lake Borgne, the earthen walls crumbled, allowing massive flooding across the suburbs and rural areas of St. Bernard Parish overseen by the Lake Borgne Basin Levee District. Other levees in the Orleans Levee District that had "subsided" were overtopped by the flood, helping inundate eastern sections of New Orleans, according to engineers.

A Corps of Engineers official says that even if those levees had been built back to their original heights before the storm, they probably wouldn't have held back Katrina's storm surge because they weren't designed for such a strong hurricane.

Members of the Orleans and Lake Borgne districts say they did all they could to make Congress aware that their levees needed work, noting that their systems passed annual spring inspections by the Corps. "I don't blame any levee board in this state and anybody who does is foolish," says Randy Odinet, a member of the Lake Borgne board.

One of two levee boards in Jefferson Parish, west of New Orleans, took matters into its own hands in the spring of 2004, spending about $200,000 to install temporary structures filled with sand and gravel on top of its sinking levees. Work had begun on raising the heights permanently earlier this year. "We had to have protection," says Fran Campbell, executive director of the East Jefferson Levee District. "We couldn't go to our people and say, 'Sorry, the Corps didn't have the money to lift the levees, so you flooded.' " When the storm surge driven by Katrina's 145 mile-an-hour winds arrived, it didn't top those levees, Ms. Campbell said.

The Orleans Levee District and its board of political appointees were created in 1890. It pursued a massive campaign to raise earthen walls around the city -- using hand laborers to add a million cubic yards of earth to the levees by 1896 and a further 15 million cubic yards using mechanical equipment in the early 20th century, historians say.

After his 1928 election, Huey P. Long, Louisiana's fabled populist governor, packed the board with cronies. The same year, the Legislature gave the board authority to fill portions of Lake Pontchartrain, the vast body of water to the north of New Orleans, and use the land it created for "places of amusement" and recreation.

The Orleans board gradually bought or seized thousands of acres of land for the flood-control system, spent hundreds of millions of dollars to build or modify levees, floodwalls and spillways -- and made itself landlord to the city's lakefront entertainment.

The levee board also built two marinas on its lakefront property. Subdivided tracts sold for development in the 1940s and 1950s became among the priciest real estate in the city. It also constructed parks, walking paths and fountains up and down the levees -- sometimes with taxes generated for flood-control measures.

In more recent years, the board hatched and then abandoned a company called Floodcom in 1994 to string fiber-optic cable through 26 miles of levees. The board's biggest gambit beyond its essential flood-control mission was signing a lease with the floating Belle of Orleans casino to help boost business at its lakefront marina. The levee board spent millions building roads to the marina and takes a small cut of the gaming revenue. The levee board justified extracurricular interests as a means of generating levee-protection funds, boasting in a 1995 brochure: "We protect against hurricanes, floods and boredom."

The modern division of responsibilities for levee oversight evolved through a series of studies and mutual agreements between the Army Corps and the levee boards.

But Orleans Levee District officials appear uncertain about some details of their charge. Outside engineers who examined the levees after Katrina found evidence of poor maintenance along the 17th Street and London Avenue canals, both of which breached. Their report cited the growth of brush and trees on the earthen embankments, which can weaken the structures. The Army Corps says maintenance should involve removing trees or brush.

Stevan Spencer, the Orleans district's chief engineer, said his crews cut grass on the outside of the canal embankments, but that responsibility for the canal channel likely falls to the sewerage and water board. The sewerage board, however, says it doesn't maintain or inspect the major canals that drain into Lake Pontchartrain.

Mr. Spencer said he was unaware of trees growing along the embankments but said some brush growth can help prevent erosion, although he knew of no specific instructions from the Corps about how much growth to allow.

The September 2004 derailment of a train on the western side of the Industrial Canal received little attention in the local media, but it severely damaged Floodgate W-30. Jim Bridger, general manager of the Public Belt Railroad, says he hand-delivered to the levee district last December a check for $427,387.96 to pay for repairs to the paralyzed floodgate. "I wanted to take responsibility," he says, "and pay for it so they could expedite repairs before the hurricane season."

But the Orleans levee board didn't award a contract for the job until May 18 -- two weeks before the official June 1 start of hurricane season. Mr. Spencer cited an initial dispute over funding of the repair and said the contracting and design process is unavoidably time-consuming.

While that contract idled, the Orleans levee board kept busy with nonflood-related projects. The board leased space to a pharmacy and issued an honorary certificate to its "Police Officer of the Quarter."

When Katrina struck, Floodgate W-30 was still under repair, so workers filled the gap with sandbags. They were no match for the wave that hit. Storm surge poured through the gap into neighborhoods to the south and west, outside engineers concluded, before the more-publicized breach on the Industrial Canal's eastern side, which flooded the lower Ninth Ward and other areas.

Along the Orleans Avenue Canal, the only major canal in the city where floodwalls didn't suffer a catastrophic failure, water instead flowed over lower levees near the canal's pump station. Outside engineers later identified barriers of five different heights near the station, including concrete floodwalls that adjoined "substantially lower" earthen levees.

"The chain will break at its weakest link," says Robert Bea, a civil-engineering professor at the University of California, Berkeley, who was part of the National Science Foundation team. Multiple agencies had jurisdiction in the area, including the levee district and the sewer and water board. Mr. Spencer, the Orleans district engineer, had warned the Army Corps in October 2004 that flood protection around the pump station was "inadequate" and required immediate attention.

The Orleans Levee Board's former president, James Huey, resigned last month under pressure from Gov. Kathleen Blanco, after his bid earlier in the year to obtain a salary without seeking approval from the full levee board became public. By law, board members earn a $75 fee for each meeting, and must also have administrative duties to draw a salary.

Mr. Huey obtained opinions from two lawyers to back his contention that he was eligible for a salary. Without seeking approval from the full board, he directed the district's executive director in a letter on July 8 to begin paying him a salary of $1,000 a month, including back pay dating back to 1996 -- when Mr. Huey became board president -- minus any fees he had already earned. That totaled about $96,000, Mr. Huey said, or nearly $58,000 after taxes. The state attorney general ruled last month that the payment was illegal, in part because Mr. Huey didn't obtain board approval.

Mr. Huey said he did nothing wrong but last week returned the check, saying that the brouhaha was distracting the district's efforts to rebuild after Katrina: "I became a lightning rod for some reason."