LA River Historical Flows, circa 1879
February 3, 2022 § 5 Comments
Just a quick note to add some perspective to a recent LA Times article about treated wastewater discharged into the LA River and the possibility that this could be reduced. The amount of water in the river in its “beforetimes” has been the subject of quite some argument that sometimes gets trotted out to justify modern decisions. So here’s documentation from the State Engineer William Hammond Hall circa 1877 (Emphasis mine):
The drainage of the Los Angeles river after leaving the Sierra Madre Mountains is received into the large basin of the San Fernando Valley, whose soil is gravelly and porous, but probably underlaid with an impervious substration(sic) of clay or rock , and acting as a great sponge, it holds the water it receives and gives it off slowly. This valley is shut in on the south of the coast range at the foot of which the river runs, finding an outlet through the hills by a narrow gap just above the city of Los Angeles. The streams emptying into the basin are the Paloma, the Pacoima, the Tujunga, and the Verdugo, of which the largest is the Tujunga. Like all the mountain torrents which descend from the Sierra Madre, they have a very rapid fall, and on reaching the valley spread out into broad “washes”, whose beds are composed of boulders gravel and coarse sand. In flow they flow entirely across the valley to the Los Angeles river, but in summer the water barely emerges from the mountains, and sinks from sight in the porous channels. The Arroyo Seco, another large tributary having the same characteristics as the other mountain torrents, enters the river at the city of Los Angeles.
In May last the discharge of the river at the mouth of Tujunga Wash ten miles above the city, where the upper dam of the Los Angeles irrigation system is located, was 24 ½ cubic feet per second. This amount was augmented by about 54 cubic feet per second from springs rising in the bed of the river at various points between this dam and the city. The total available supply therefore was about 78 ½ cubic feet per second. An amount which is but little diminished during the summer months.
Below the city the river is broad, shallow and sandy, and only upon rare occasions does the water ever find its way entirely to the sea, but is absorbed by the thirsty sand.
-State Engineer William Hammond Hall Papers, Misc. Working Papers, General Irrigation Info, Reports- LA County (Schuyler)
Which are at the State Archives under AC 91-06-10
(Schuyler FWIW is the actual person taking the measurements and writing the notes…The dam mentioned is near present day North Hollywood. That total flow description is for flow approximately near Figueroa Street in Northeast LA – He doesn’t mention any inflow from the Arroyo Seco, so it’s hard to say if he was measuring above or below that)
It’s a shame the terms of contemporary debate are so narrow that serious people only argue about how much life support (treated sewage aka used imported water) to give the river – if any. In some parallel universe there is perhaps a dialogue being had about recharging groundwater, reconnecting floodplains, and removing or reducing the effect of dams on river flows… but for us, in this universe, we don’t even have in the English language much of a functioning subjunctive tense with which to describe the possibilities that the river (and we) deserve, without being laughed out of the room.
But the subjunctive still gives us this: Long live the river!
L.A. Creek Freak 
Errata: Originally published saying Circa 1877. The surveyor Schuyler was in the LA area making these observations in 1879.
Love the historical stuff always (you can imagine the look of the LA River and its native contents, both plant and animal in the nineteenth century, and I do!). The phrase about the flow of the River NOT going down in the summer stood out to me, even when the population then was tiny compared to now. Thanks for your efforts on behalf of our watercourse!
Arroyo Seco means dry valley. I’m guessing that, unlike the Los Angeles River proper at that point (the flow of which was fairly consistent year-round, as he notes), discharge from the Arroyo Seco was extremely variable, as it still is today. The LA River is/was fed by the “sponge” of the San Fernando Valley; the Arroyo Seco has no such upstream source to moderate and regulate its flow. So, a water planner would not include it in his calculations.
At the beginning of the 20th century, the Arroyo Seco was dry most of the year, but it was considered an attractive place for hiking and picnicking. There were lots of nice boulders to climb on, which ended up being used for building. Årroyo does not mean valley, either. It’s an untraslatable word the Spanish used for a watercourse.
The L.A. Times writer seems to have forgotten that the area where the kayaks run does have a year round flow, and always has. The engineers were unable to pave the bottom of the river because it was too wet! They had to content themselves with paving the banks, alone.