Grant nodded. "By far, the two biggest are Davis and Parker, which hold back Lake Mojave and Havasu. Both of those have spillways that, theoretically, should be able to keep up with Hoover. Downstream are two small dams, Head Gate Rock and Palo Verde, which have comparatively little storage. Their primary purpose is to divert water for irrigation. As a worst case, we expect both of these dams to fail. However, neither should substantially affect floods downstream. The one we're worried about is the Imperial Dam, just north of Yuma, Arizona. It'll definitely be breached and we'd like to figure out a way to minimize the damage. As I explained before, Yuma is where the United States desalinates the water going to Mexico. So we want to protect the desalination plant."
"Approximately how many hours will the flood last? How soon will you be able to get people in to access the damage and make repairs?"
Grant stared at Phil. "It's not hours, Phil, it's months. It'll be almost two months before Hoover drops below the spillways. If we're lucky, the people can move back in and start sifting through their stuff by September 1st."
Phil's jaw dropped and he walked over and sat down. "Two months of Niagara Falls?"
"Two months of Niagara Falls times two," Grant corrected.
"I had no idea." Phil looked around, then back at Grant. "What about Mexico? What's going to happen there?"
"Well, before it gets to Mexico, there's the Laguna Dam. It's less than ten feet high. It won't even slow the water down. The dam in Mexicali, Mexico is called the Morales Dam. Its primary purpose is to divert the water into the Gila canal. It's not very big, and if the water destroys it, maybe the United States can help them rebuild it."
"What about downstream from Morales? Any more dams?"
Grant shrugged. "No, that's it."
"And your girl's list shows timelines for all these dams?"
"Yeah, she did a good job. She wrote a crude model for the whole thing. It lists estimated times for each reservoir to fill, and water travel times between dams."
Phil stood. "All right, we have a lot of phone calls to make. Hopefully we'll get some National Guard personnel to help us."
Grant got the distinct impression that the interview was over. He walked toward the door of the small conference room. "I'll send Shauna up with your info." He heard Phil respond that he appreciated it as he walked out the door.
The skinny man took the exit. The truck needed gas. After blowing up the aqueduct, he had continued west and skirted the south side of Joshua Tree National Park, then joined I-10, which passed by Palm Springs and all the windmills. The exit put him in Riverside, California.
Back when he planned this day, he wanted to follow the Colorado River south, but he knew the cops would be looking for him. There would be road checks and detours, and staying near the river would be too risky. It would be bad enough to get caught, but especially out on the open highway traveling between targets. Ultimately, he had decided he had plenty of time. The long detour through Southern California would almost guarantee he would go unnoticed.
After starting the gas pump, he fished through his glove box and found the address of his next destination. A map had been printed from his computer. Days before, after calling numerous persons advertising on recycler.com, an online classified advertising company in Southern California, the skinny man had found the vehicle he was looking for. A deal had been made. Now all he needed to do was show up on the guy's doorstep before noon. The seller was expecting him.
When the tank was full, he looked at his watch. He saw a few fast food restaurants just down the street and decided he had time for breakfast.
Grant and Fred had climbed to the top of phase one of Hoover-Two. They walked carefully along the sandbags. Where they walked, it was only ten feet wide. Looking north over the lake, the employee parking lot was gone, covered with water. A slight breeze blew down Black Canyon, rippling the surface, but the breeze was not refreshing, as the air temperature crept toward 100 degrees, even early in the morning.
For the last hour or so, the construction of the dike had transitioned from phase one to phase two. The ten-foot-high dike was finished and stretched from the cliffs on the Arizona side to the cliffs on the Nevada side. Phase two called for widening the dike from half the width of the dam to the full width, and building it up to a full height of twenty feet. The transition meant that trucks would no longer be able to drive across the dam and turn around, but would need to back up to unload sand bags. Phase two was gradually being built from the Arizona side toward the Nevada side.
Over the noise of the trucks and men, one could still hear the rumbling sound of the two spillways. By referencing off the concrete handrails on the top of the dam, Grant could approximate that the water level had risen about two feet above the concrete, meaning that two feet of water would be flowing over the top of Hoover if the sand bag dike wasn't there. So far, the dike was doing what it was supposed to do, a very satisfying feeling.
Fred seemed to read his mind. "This place would look a little different with a small waterfall stretching all the way across the dam, wouldn't it?"
Grant laughed. "I wouldn't mind a small one; it's a fifteen or twenty footer that I don't want to see."
Grant turned to Shauna who had just joined them on the dike. "How are we doing on water levels?"
She adjusted her glasses. "The rate at which the water is rising has started to slow slightly, even though the floods entering the lake are still peaking. That's mostly due to increased flood area of the landscape upstream as the water rises."
Fred laughed out loud. "In English?"
Shauna looked uncomfortable. "What that means, Mr. Grainger, is that the higher Lake Mead rises, the more it spreads out. It therefore takes much more water to make it rise. Basically, the surface area of the lake is growing faster than the flood, therefore the rate the water is rising in the lake is decreasing."
Fred, still laughing, struggled to talk. "I thought I understood, Miss Kingsly. I just wanted to see if you could say it in simpler terms."
Grant and Fred both laughed again.
Shauna smiled in spite of being the object of their joke. Grant didn't want to upset her, even if she did have a vocabulary problem. She had been invaluable on this trip, and her estimates had been near perfect.
"Are the levels still within our projections?" Grant asked.
She nodded. "Yes. In fact, I've reduced my projection for maximum depth from Hoover plus thirteen to Hoover plus twelve and a half."
"That's great. I'll take all the 'halves' you can give me," said Grant. "By the way, did you get that table of downstream stuff to the FBI guys?"
She nodded. "Yeah."
"Thanks." Grant considered the information. "What about time? Have you changed when you expect Hoover to peak?"
"No. I monitored the reports of peak flood stages as they moved through the Grand Canyon last night, and I actually expect peak flows to be entering the other end of Lake Mead within the hour, then decreasing gradually. However, flow into the lake will remain greater than 500,000 cubic feet per second until late this evening, approximately 9:00 p.m. After that, the lake should start to drop very slowly."
Grant remembered something that had crossed his mind while talking to the FBI. "Were you able to get a hold of anybody at the three small dams downstream yet?" He worried about them, because they were not under direct control of the Bureau of Reclamation. Headgate Rock Dam, whose major purpose was to divert water to the Colorado River Indian Reservation, was actually controlled by the Bureau of Indian Affairs. The Palo Verde Diversion Dam was managed by a bunch of farmers in the Palo Verde Irrigation District. And Imperial Dam, way down by Mexico, was managed by the Imperial Irrigation District, the same group that managed the All American Canal, the largest of all the Colorado River aqueducts.