Arroyo Seco (Los Angeles County)

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[edit] Devil's Gate Dam and Hahamongna Watershed Park

Enhanced profile of Devil Rock next to the Devil's Gate Dam. The dam was rebuilt in the 1990s, but the granite image of the devil was gunited over two decades before that.

Despite the Arroyo Seco's dry name and the semiarid climate of the region, periodically torrential floods from the steep, erosion-prone mountain watershed of the Arroyo Seco would race through the communities of this region all the way to Los Angeles. The reputation of Arroyo Seco floods led the early settlers of Los Angeles to situate their pueblo on a bluff out of the way of the confluence of the Arroyo Seco and the Los Angeles River. As population multiplied in the region, the damage from these floods was particularly severe in 1914 and 1916.

In 1920 flood engineers built Devil's Gate Dam in the Arroyo Seco, the first flood control dam in Los Angeles County. Named for a rock outcropping which resembles the face of a devil, Devil's Gate gorge, located in Pasadena between La Cañada Flintridge and Altadena, is the narrowest spot in the Arroyo Seco.

Above the dam is the flood basin which captures the flows of the mountain watershed of the Arroyo Seco. This area is now called "Hahamongna," a phrase meaning "Flowing Waters, Fruitful Valley," a remarkably different designation than the name given the area by the Spanish explorers. Hahamongna also refers to the original Native American tribe of the Tongva Indians who once inhabited the area. Pasadena is developing the Devil's Gate/Hahamongna flood basin into Hahamongna Watershed Park, a 1400 acre regional park, which emphasizes the unique natural values of the park.

[edit] The Arroyo Seco Stream

Below Devil's Gate Dam, the Arroyo Seco stream is contained in a concrete channel which captures stormwater and municipal runoff. This channel and other similar flood control structures along the foothills of the San Gabriel Mountains were built following the devastating deluge and flood of 1938.

Just below the dam, the Foothill Freeway (210) bridges the Arroyo Seco channel and as does the Colorado Street Bridge two miles further south. The channelized stream proceeds south through Brookside Golf Course, past the world famous Rose Bowl, and Brookside Park in Pasadena. After passing under the Ventura Freeway (134), the stream cuts through the Raymond Fault at the southern boundary of Pasadena and continues south between South Pasadena, and Highland Park and Montecito Heights in Northeast Los Angeles. In this stretch, the Pasadena Freeway (110), also known as the Arroyo Seco Parkway, the primary highway between Pasadena and Downtown Los Angeles, runs parallel to the stream until it reaches the Los Angeles River near Dodger Stadium.

[edit] History

A view of Devil's Gate on the Arroyo Seco river prior to any damming. Note the devil's profile in the rock to the right

[edit] Mythology

Above Devil's Gate, the rapids of the Arroyo Seco are so positioned so that the falls make a beating, laughing sound. Mythologically, this is attributed to a wager made between the river and the coyote.

[edit] Early settlement

The Arroyo Seco was one of the Los Angeles River tributaries explored by Gaspar de Portola in the late summer and fall of 1770. He named the steam Arroyo Seco, for of all the canyons he had seen, this one had the least water. During this exploration he met the Chief Hahamog-na (Hahamonga) near Millard Canyon. These Indians would end up gathered into the fold of the San Gabriel Mission and with other tribes collectively called "Gabrielenos." The Arroyo Seco can be considered by all historical accounts the birthplace of Pasadena. After the secularization of the Missions, the broad area to the east of the Arroyo was named Rancho San Pascual (see Pasadena, California). On the east ridge of the Arroyo in what is now South Pasadena, Manuel Garfias, the longest tenant of the Rancho, built his adobe.

With the establishment of the Anglo community of the Indiana Colony (early Pasadenans) in 1874, the new residents built their homes along today's Orange Grove Blvd., a major north-south street which parallels the Arroyo. However, the Arroyo presented a great barrier to easy travel and transportation to and from Los Angeles. Stories of four and five hours just crossing the chasm, whether exaggerated or not, abound in Pasadena history.

[edit] Lines of transportation

By 1895 a railroad line had been established from Downtown Los Angeles with a grand wooden trestle that cut a straight line crossing from the west side to the east. Eventually this line would hook up with rail lines built from the east to create the cross-country course of the Santa Fe Railroad. For local commutes, an electric traction trolley was put in and operated by the Pacific Electric Railway, a Huntington enterprise, which ran from points northeast into Los Angeles and other points beyond.

In 1900 Horace Dobbins opened his cycleway, an elevated wood structure with a flat planked byway that would allow bicyclers to travel from Pasadena to Los Angeles free from the uncertain schedules of PE trains. Dobbins was only able to build a course of the cycleway from the Green Hotel to Raymond Hill before he was stopped. It is suspected that the competition was too much for the railroad, and Dobbins was politically ambushed from completing his project.

In 1913 The Colorado Street Bridge was dedicated. This was the first straight line traverse of the Arroyo accessing Eagle Rock, Glendale and Downtown Los Angeles. During the Stock Market Crash of 1929 and the subsequent Great Depression of the 1930s, the bridge was a jumping off point for many committing suicide, whereby it received the ignoble name of "Suicide Bridge." By the 1980s the bridge fell into great disrepair as chunks of concrete dropped from its face to the armory parking lot below. After the Loma Prieta (near Oakland) earthquake of 1989, the bridge was closed as a precautionary measure. Eventually assistance from the Federal Bridge Repair and Replacement Fund and other local governmental agency discretionary funds provided for the complete restoration and seismic retrofit of the bridge which reopened. The total project amounted to $24 million and the bridge was reopened on Dec. 13, 1993, which surprisingly was on time and on budget.

The automobile had long become a mainstay of Southern California life, and in 1940 the first freeway, The Arroyo Parkway, was built along the flood channel. Today it is the upper section of the Pasadena Freeway, which passes through downtown and terminates in San Pedro.

[edit] Jet Propulsion Lab (NASA)

Jet Propulsion Laboratory was established at the head of the Arroyo Seco in 1930 by the California Institute of Technology. In the 1950s the laboratory was heavily involved in rocket testing, and the roars of rocket engines could be heard emanating from the canyon for miles. These rocket projects were terminated at the facility by 1958. By the mid 1960s JPL had become highly instrumental in the development, launching and tracking of a number of unmanned near-space and deep-space spacecrafts. One of their most recent projects is the Mars Rover which has returned a number of panoramic photos of the Martian surface.

On a public relations side, JPL has been sharply criticized by local environmentalists for their contamination of the local groundwater with toxic chemicals such as solvents and a rocket fuel accellerant called Perchlorate. A monumental cleanup project has been launched by NASA which includes a multimillion dollar pumping and filtration system to pump and treat the groundwater until the contamination level has been reduced to acceptably safe levels. The project is being staffed by a special project team from NASA and duly monitored by the EPA. Frequent public meetings are held and public comment recorded for the record on the progress of the cleanup.

[edit] Attractions & landmarks of the Arroyo Seco

in succession from north to south:

Switzer's Falls
Millard Canyon
Jet Propulsion Laboratory NASA
Oak Grove Disc Golf Course
Hahamongna Watershed Park (formerly "Oak Grove Park")
Devil's Gate Dam
Brookside Golf Course
Rose Bowl
Colorado Street Bridge
Hotel Vista Del Arroyo (currently home of the 9th District Court of Appeals)
Batchelder House
Arroyo Parkway
Metro Gold Line (Bridge crossing and Ave 57 Street Station)
Southwest Museum
Charles Fletcher Lummis Home - "El Alisal"
Heritage Square

[edit] References

Pasadena, Hiram Reid, 1895. Out of Print. A comprehensive history of Pasadena after 20 years of colonization.
Trolley Days in Pasadena, 1985, Charles Seims.
Most information derived from the archives of the Pasadena Museum of History.