This 2004 story from the Los Angeles Times, though focusing on water shortage, is especially relevant now that the Sacramento River is running high and fast; as it details how Shasta Dam was originally engineered to be 200 feet higher, (and could easily be raised by that height now) tripling its water storage, and virtually stopping flood concerns on the Sacramento.
Here is an excerpt.
"As California looks for new ways to increase water supplies in the face of mounting shortages, this monstrous 602-foot facade holding back the Sacramento River seems destined to grow even taller.
"It's a perfect spot for expansion, although it's not the only site under intense scrutiny in this scramble for new water storage.
"Shasta Dam was designed to be 800 feet tall, so adding concrete to its top presents no significant engineering obstacles.
"This is like adding a room on a house, rather than building a new house," said Michael J. Ryan, the Bureau of Reclamation's Northern California area manager, whose small office overlooks the dam, the lake and, on a clear day, Mount Shasta looming large in the distance.
"But most importantly, the clean, cold water it would add to the state's supply is exactly what water managers are looking for. A taller dam means additional downstream protection against floods, more downstream supply for farms and cities and, because Shasta Lake would be deeper, more cold water to send downriver when the salmon are looking for a place to spawn.
"A recently enacted federal water bill governing the state-federal San Francisco Bay-Delta restoration and water program commonly known as Cal-Fed revs up studies to add as much as 18.5 feet of concrete to the top of the dam. That would boost the size of the lake behind by some 15 percent, or 636,000 acre-feet - enough water for 1.2 million households.
"At an estimated cost of nearly $500 million, the project would be relatively cheap. Under the Bureau of Reclamation's current timetable, construction could be under way in five years and completed in 10.
"All that looks promising for Northern and Central California, where water shortages in a normal year are expected to be 1.4 million acre-feet by 2020 - and three times that in a drought year."