The Oroville Dam, the tallest dam in the nation and California’s second-largest reservoir, has been in the news a lot this month: last Sunday, February 12th, nearly 190,000 people were evacuated from counties that are located downstream of the dam, as officials were extremely concerned that the spillway would fail, and thousands of gallons of water would rush downstream. This month, the spillway at the Oroville Dam, which was built in the 1960s, was subjected to “massive volumes” of rain water, and the aged concrete has not always been repaired adequately when it developed cracks, leading to questions about the design integrity of the dam. The spillway has also slid downhill in the past, which opens up surface gaps, and the prior drought caused the underlying soil to shrink, so all of the recent rain water had plenty of underground fissures to fill. The Los Angeles Times quoted a retired dam engineer who called the damage to the spillway “an accident waiting to happen.”
The real trouble began on February 7th, when the main concrete spillway’s gates were opened and started breaking apart, which allowed 55,000 cubic feet of water/second to gush down the slope, eventually digging a huge hole in the terrain 45 feet deep. The spillway is not part of the dam: it’s actually an extremely important safety system at the site, and must be strong enough to hold up under extremely intense forces when the reservoir is filled to capacity by storms. Robert Bea, a retired civil engineering professor at UC Berkeley who was in charge of one of the Hurricane Katrina investigations into the levee system of New Orleans, told the LA Times that the “dead weight of the water alone was more than 5 tons per square foot.” Luckily, according to The Mercury News, the water elevation behind the Oroville Dam has continued to drop. The California Department of Water Resources set a goal of 850 feet, and as of Sunday morning, February 19th, the reservoir’s elevation was at 852 feet, down nearly 50 feet since the water started flowing over the emergency spillway eight days prior.To remember how the man spillway looked before the hole was torn into it, the Earth Observation Sciences & Geographic Information Systems S.L (EOSGIS S.L.) created a 3D model of the Oroville Dam and the surrounding area, and published it on Sketchfab. EOSGIS, which is headquartered in Madrid, has been a member of Sketchfab for about a year, and has published other topographical 3D models, including one of the Leeds area.
EOSGIS integrates data with GIS, along with any other information or maps it’s provided with, to create custom cartography. They specialize in 3D terrain visualization, making an initial analysis of the terrain and the data, in order to display information like rivers, roads, and vegetation, onto a 3D representation with a realistic finish. This would be especially helpful for use in urban planning, architecture, and civil engineering.