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ENR Files from the Front

Iraqi Dam Has Experts On Edge Until Inspection Eases Fears
Mosul Dam

For weeks military intelligence on the Mosul Dam, a major hydroelectric and irrigation impoundment in northern Iraq, had delivered a variety of scenarios, none of them good for coalition efforts to rebuild Iraq. One version in early April indicated that Iraqi forces had wired the structure for detonation. Another more recent report claimed the dam's foundation was "leaking like a sieve and ready to collapse."

Either case would set in motion a cascade of catastrophe, unleashing as much as 12.5 billion cu m of water pooled behind the 3.2-km-long earth-filled impoundment thundering down the Tigris River Valley toward Mosul, the second largest city in Iraq. The wave behind the 110-m-high crest would take about two hours to reach the city of 1.7 million. Telecommunications systems operated sporadically even before the war; how much advance warning the victims would have these days is anybody's guess.

The dam is a key component in the nation's power grid, with four 200-Mw turbines. Ranked by the World Commission on Dams as the Middle East's fourth largest, in reservoir capacity, it also captures spring snowmelt from Turkey, about 70 miles north, and stores water for irrigation. A breach would not only kill people downstream quickly, it would also cause prolonged suffering through power outage and drought.

With so much at stake, two Army commanders wanted to make a first-hand threat assessment. On April 24, Col. Gregg Martin, commander of the 130th Engineer Battalion, had already planned to make a site visit to a bridge reconstruction project in Saddam Hussein's ancestral homeland of Tikrit. With his "dam wizard" and deputy brigade commander Lt. Col. Mark Holt and several other soldiers in tow, Martin asked Col. Ray Palumbo, commander of the 12th Aviation Brigade, for help with transportation. Palumbo has a fleet of Blackhawk helicopters at his disposal at an airstrip north of Baghdad. He assigned two choppers to the task, co-piloting the lead bird himself.

Tigris Bridge requires structural repairs.

At Tikrit, Palumbo sets down inside the perimeter of what was until April 13 Saddam Hussein's hometown retreat. It is now the Fourth Infantry Division field headquarters. The lavishly ornate compound is a monument to conspicuous consumption and dubious taste, a Babylonian Graceland. Martin doesn't dawdle. He makes a beeline for the base of the 500-m, 18-pier span to get an update from Col. Bob Nicholson of the 4th ID. As division engineer, he is preparing to repair the crossing. Explosives–either from retreating Iraqis or from coalition airstrikes--have blown holes in the deck between several spans. Divers are surveying the river, which is out of its banks, flowing swiftly, but not yet at flood stage. A six-man Army dive team is conducting surveys of the piers and the under deck. Preliminary plans call for repairs within the week, using a combination of assault floating bridges and Mabey-Johnson bridging. Successfully spanning the gap will be "on the order of [the] Sava River crossing in 1995 in Bosnia and Herzovogina (ENR 1/08/96, p. tk)," says Holt. It would also reopen a direct route from Tikrit to Kirkut.

Saddam Hussein's family getaway in Tikrit

While Nicholson is briefing Martin on the equipment and preparation work needed to repair the bridge, Palumbo checks out the restrooms in one of the compound's smaller buildings, at the base of the bridge. "Nine toilets, nine bidets–all gold plated. And that's not the main building. It's obscene," he says later as the recon team is airborne again, headed north to check out the dam.

Unlike the dry and barren Shia country in southern Iraq, where Saddam Hussein clenched the irrigation valve with an iron fist, the Sunni region north of Baghdad to Tikrit is lush, arable land. Here water drawn from the Tigris and Euphrates flows freely through irrigation canals that nourish row crops, palm plantations, grain and pastureland. The view from a helicopter flying at 120 knots 50 to 100 ft off the ground suggests that the humanitarian grain and rice shipments headed to Iraq will not be needed in this part of the country. One soldier observes that "lack of rain causes drought. Bad government causes famine."

The helicopters fly past Mosul and approach the dam. Behind the face, azure water looks cool and pristine, a far cry from the brown and green murk down-river toward Baghdad. Water rips through the spillway, churning up white foam waves. The pilots and gunners notice a cluster of people milling around chairs arranged on one wing of the dam, apparently gathered for some sort of outdoor gathering. At the other end are about a dozen men in green uniforms, black boots and red berets. They are carrying AK-47 rifles. As soon as he sees the Blackhawks, one sprints to an outbuilding. Nobody in the helicopter recognizes the uniforms. The helicopters hover back and forth across the dam face like dragonflies.

"What do you want to do, Col. Martin?" asks Palumbo through the headset.

"Don't land if you don't feel the site is safe," Martin says. "But it's your call, Ray."

Palumbo pauses for a few seconds. "They've had ample opportunity to shoot at us if they want to," he says, as if to himself. The people in the chopper wave. The people on the ground wave back. Palumbo makes a tactical decision. He instructs the other chopper to stay aloft and be ready to provide covering fire. Then he sets the Blackhawk down on a bench above the wingwall near the spillway, opposite the more heavily guarded side housing the turbines and control room. He keeps the rotors turning.

Col. Martin takes dam briefing from engineer Mahmoud

Martin and one of the gunners head for a control shack and are quickly in a conversation with Jassam Hammad Saleh Mahmoud, an engineer in charge of operations on the irrigation side. He apologizes for his English. He says he has not spoken that language since 1983, during the dam's construction. He explains that Turkey has experienced a winter of heavy precipitation, after three dry years. The spillway has been closed during that time. Last month, rain and snowmelt began filling the reservoir. There are about four meters of freeboard to the dam's crest. In a typical year, Mahmoud says, the spring spillway flow rate is about 750 cu m per sec. At present, he is dumping 2,500 cu m through the spillway and turbines.

The other chopper has discharged Holt, who quickly moves the conversation to the essential question: the dam's structural integrity. From 1999-2002, Holt was stationed in the Corps of Engineers' Seattle office. The previous night he contacted some of his comrades there for a quick review of significant questions to ask for an evaluation of the dam's structural integrity and hydroelectric performance. In recent years the Corps has touted developed an approach that lets field observers "reach back" to the U.S. for technical expertise. Holt is putting that theory into practice. He quickly works through a checklist of trouble signs, until he is confident that the dam is not in danger of failure. Then he compiles as much intelligence as he can in an hour. Both choppers are in the air, for security. Each is carrying about 90 minutes worth of fuel.

Lt. Col Holt inspects grout gallery in dam's core.

Mahmoud explains that the dam leaks, but is structurally sound. This is confirmed, he says, by data from a full array of piezometers--mostly downstream, but some above the dam. The foundation rests on three strata of gypsum. There is some seepage beneath. But the dam engineers, a German-Italian joint venture called GIMOD, designed an aggressive grouting program to deal with this. Concrete lined grout galleries, each some 1,600 m in length, extend from each wing to the center, in the dam's core. Mounted lines on the gallery walls deliver bentonite, cement, water and air to make grout for portable drilling machines. Four crews are working in one gallery. There are 12 machines in all. Another wall-mounted line extracts water. Grout injection wells are evenly spaced approximately 10-20 m apart. The grout curtain extends to a depth of 90 m. The dam consumes some 50 mt of grout a day, under normal maintenance. Voids throw the program into emergency status and have consumed up to a quarter million tons of grout a day. Mahmoud believes better grout would reduce the consumption. Quality grout is one more material that has been hard to come by, either because of post-Desert Storm sanctions or because of the regime's other priorities.

Kurds are accused of looting in Mosul, but dam operators say PDK militia saved the powerplant and dam nearby

When the discussions turn to the power side of the dam, Mahmoud offers to take the group along the road across the dam crest to the powerplant. Along the way, they pass the soldiers, who are friendly, yet disciplined. They learn that the militiamen are members of the PDK, the Democratic Party of Kurdistan. Their leader is Massoud Barzani. The other organized group of Kurds in northern Iraq is the Patriotic Union of Kurdistan (PUK), led by Jalal Talabani. U.S. Special Forces reportedly have been working with both rival groups. These uneasy alliances became even more important about two months ago when Turkey turned down U.S. plans to launch the Fourth Infantry Division from Turkey.

Mosul's ethnic split is about 70% Arab and 30% Kurd. Looting in Mosul after Baghdad fell was blamed on the Kurds. Not at the dam, however. "These soldiers came about 10 days ago and protected the powerplant from looters," says Ra'ad Benhan Hanna, an electrical technician at the plant. He goes on to say that the dam workers–178 on the power side and 300 or so on the irrigation and flood control side–have been working without pay for the past month, since the war started.

Martin and Holt discuss operations with Mosul Dam power staff

Even more amazing is that, except for a two-week shutdown during the war, they've been running the plant manually, for a long time. The plant has instrumentation, but the computerized controls are shot. The operators open or close the spillways and "tune" electrical output by reading the dials–doing what PCs do in most modern power plants. The plant has a downstream pumped storage module that makes operation even more complicated. Yet the powerplant operators show Holt electricity production data curves that attest to their competence. "Optimal output is 50 cycles and these guys say they're hitting 49.9999," he says.

The mainframe computers came from ASEA, now ABB, when the plant was constructed from 1981-86, says the computer technician, who gives his name only as Amman. Spare parts are an elusive dream. "We haven't been able to get Control Data disc drives for years," he says. He offers three solutions, along with cost estimates. The fast fix is a moving head disc and computer cards for the existing, if antiquated, mainframe. The cost: $100,000 to $200,000. The medium solution is to hire a Baghdad-based firm, Electrical System Co., to replace the controls with a PC-based system and write software in C language. Total expense: around $400,000, he says. The slow solution, or long-term fix, would outfit the plant with ABB's "Spider" system controls, for $2 million to $3 million, he says.

The operators tell Martin and Holt that they are producing 630 Mw from four 200-Mw turbines--more power for Mosul than they did before the war. Military intelligence confirms this, putting the production level at about 80% of demand. But they also say they are unable to push power south to Baghdad for the national grid, because of breaks in the 400-kv transmission lines. One line is between Baji and West Baghdad. The other is between Balad and Baghdad, they say. They also provide a name and contact at the North Region Control Center to provide more information on conditions in Iraq's northern power transmission grid.

Palumbo, left, and gunner, sidearms drawn, check hidden Iraqi helicopter

Intelligence in hand, the Americans bid farewell to the dam engineers and operators and the PDK soldiers and board the Blackhawks to head back. On the way home, Palumbo and his crew set down in a dry wash a few kilometers above Mosul to check out something they noticed earlier on the way to the dam. There are about 15 Russian-made helicopters, rotors off, stashed under camouflage netting. Some are small recon helicopters–MI 2 Hoplites. There are also some MI 8 armored troop carriers. Earlier in the day they spotted even larger Hughes 500 birds. They record the coordinates for the evening's commanders' conference call. Perhaps the choppers will be retrieved for reconditioning and returned to the rebuilt Iraqi military. Or perhaps they'll be parceled out to other agencies in the new government. Hundred of questions like this are popping up every day, it seems.

They stop at a 101st Airborne field depot to take on fuel for the ride home. Later, Martin and Holt discover that another recon team had visited the dam the previous day. That team had collected much of the same data on the grouting and the dam's structural underpinning, but the information on powerplant operations and breaks in the transmission line is new information. They seem unperturbed. Martin tells his officers at the evening briefing: "The real hard work is just beginning. What's coming up will be harder, more challenging, more complicated than anything we've seen so far. We're going to be working our butts off for as long as we're here."



ENR Managing Senior Editor Andrew G. Wright is in Baghdad
with the Engineer Brigade of U.S. Army's Third Infantry

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