“We’re hoping for the best, but we’re going to continue to prepare for the worst,” Los Angeles Mayor Eric Garcetti said. “… If [the river] floods, there is risk of significant damage, not to mention real and immediate danger to Angelenos.”
If you’ve been down to Glendale Narrows, you know that the river encasement is already high, 20 feet, according to the U.S. Army Corps Los Angeles River Ecosystem Restoration Feasibility Study so what could a temporary four-foot-high barrier accomplish that isn’t already there? And for $4.5 million?
But the more vexing part of this emergency solution is “removing debris.” If the Corps removes the islands and plant life that dot the area, you can kiss the only structure fish have goodbye. It’s also a very healthy bird habitat. The NBC story indicates this is already taking place. Here’s the 2013 draft redesign plan for that area:
Existing Channel Features – The existing trapezoidal channel within the sub-reach varies from grouted rock to concrete paved channel, is 310 feet wide from the top of bank and 20 feet high from the invert.
Preliminary Channel Design – As seen in Figure 4.12, ” Cross-Section 5, Los Feliz Boulevard to Glendale Freeway,” the proposed design would construct four concrete terraced planters in the left/east bank of the channel slope. The right/west bank of the trapezoidal bank would be replaced by a 22-foot-high vertical retaining wall with subdrainage under the invert slab, which would meet the existing top of bank. Two riprap toedowns would be constructed below the channel bottom and bank. The first riprap toedown would be constructed on the right/west bank and the second that would include bank protection, would be located on the left/east bank. Two 16-foot-wide asphalt concrete maintenance roads would be constructed on the land of the retaining walls on the top of bank. The existing cobble/soft bottom would be protected in place and expanded 27 feet towards the proposed right/west bank of the channel.
See you on the river, Jim Burns