The key is to remove the concrete bottom. A soft bottom makes it much easier for plants to gain a foothold, for creatures to live in the riverbed, to provide places for spawning. This was done in a stretch near Griffith Park known as the Glendale Narrows, where it looks more like this:



Nobody will confuse this with a pristine river: there are abandoned grocery carts, car tires, carpets, golf balls, all manner of detritus, especially plastic bags. It is polluted by industrial and commercial runoff. But with a soft bottom, there are plants in it. Largemouth bass, sunfish, bullheads, carp, and other fish have been found in it. And birds.

Here are a few:

Herons, including Great Blue Heron (top) and Black Crowned Night Heron (I didnt know they were native to the area).



Also egrets, though I didn't get a decent picture of one.

Black Phoebe, flycatchers constantly flitting over water:



Double crested cormorants, with their brilliant green eyes:



A little help here (some sort of warbler? Vireo?):



All kinds of ducks, including hooded merganser (with a coot)



American wigeon



As well as mallards, teal, and muscovy duck. And no doubt many others I didn't see.

Hopefully more and more of the river will be restored. If any of you are birders or nature lovers in the LA area you should definitely check it out (and maybe volunteer on a cleanup or two.) But even so ... hooded merganser and black crowned night heron, kingfisher and wigeon dabbling and prowling and diving in a narrow space between the Golden State Freeway and a Metrolink service station? Who'd've thunk it?? A little bright spot from the concrete jungle.