1 Description of this unit which has been selected for construction is included in the following paragraphs.

The individual units that have been selected for construction are described in the following paragraphs.

Hansen Dam.-This unit is located on Tujunga Wash approximately 9.4 miles above its junction with the Los Angeles River. It includes a rolled-fill earth dam 9,050 feet long, maximum height 97 feet above stream bed, with a flood-control basin of 33,120 acre

feet capacity at spillway crest; an uncontrolled spillway 284 feet in length, located near the center of the dam where bedrock is available; and outlet works through the dam near the center of the structure.

The operation of the basin regulates the run-off from a tributary area of 147.4 square miles, reducing the flow of a design flood from 64,800 to 12,000 cubic feet per second.

Sepulveda Dam.-This unit is located on the upper Los Angeles River, approximately 43.1 miles above the mouth. It includes a rolled-fill earth dam 15,300 feet long, maximum height 57 feet above stream bed, with a flood-control basin of 16,700 acre-feet capacity at top of spillway crest gates; spillway 399 feet in length, located near the center of the dam; and outlet works through the dam near the center of the structure. The operation of the basin regulates the run-off from a tributary area of 155.3 square miles, reducing the flow of a design flood from 69,000 to 7,100 cubic feet per second.

Los Angeles River channel-Lankershim Boulevard to Niagara Street. This improvement provides for the construction of a rectangular concrete channel from Lankershim Boulevard to the existing improved channel at Niágara Street (a distance of 2.25 miles). The channel is designed for the probable maximum flood. Los Angeles River channel-Niagara Street to Stewart and Gray Road. The plan provides for channel improvements along Los Angeles River as follows: A rectangular concrete channel from Niagara Street to the Burbank Western Wash (1.7 miles); a trapezoidal channel with concrete slab or grouted rock protection from the Burbank Western Wash to 1,400 feet above Dayton Avenue (7.5 miles); a channel with concrete invert and either sloping concrete side walls or vertical sheet steel-pile or concrete retaining walls, depending on rights-of-way available and the proximity of main-line railroads on each bank, from 1,400 feet above Dayton Avenue to Soto Street (5.4 miles); a trapezoidal channel with concrete slab or grouted rock bank protection from Soto Street to Stewart and Gray Road (6.2 miles); and four highway bridges, four railroad bridges, and one footbridge. The unit will provide protection for the city of Los Angeles. The channel is designed for the probable maximum flood.

Los Angeles River channel-Stewart and Gray Road to Santa Ana branch, Pacific Electric Railway bridge (right bank).-The plan provides for a levee with grouted rock bank protection along the right bank of the Los Angeles River from Stewart and Gray Road to the Santa Ana branch, Pacific Electric Railway bridge (a distance of 2.34 miles). The unit will provide flood control for the low-lying area of Los Angeles to the west. The levee will be constructed as a part of the comprehensive plan for the Los Angeles River.

Los Angeles River channel-Pacific Electric Railway bridge to near Artesia Street.-The plan of improvement provides for construction of a trapezoidal channel from the Santa Ana branch Pacific Electric Railway bridge to near Artesia Street (a distance of 2.65 miles). The channel is designed for the probable maximum flood.

Los Angeles River channel-Long Beach Boulevard. This improvement provided channel rectification of the Los Angeles River at Long Beach Boulevard for a distance of about 0.397 mile, by the removal of about 154,000 cubic yards of material. The unit removed a constriction in the river channel above the city of Long Beach.

Haines Canyon.-This unit consists of extension of the existing rectangular reinforced concrete channel of Haines Canyon from Plainview Avenue to mouth of Haines Canyon (a distance of 1.8 miles), thus completing a channel 3.6 miles long from Tujunga Wash to existing debris basin. The unit also includes reconstruction of debris basin by construction of reinforced concrete spillway and outlet structure, enlargement of earth-fill embankment, and excavation in basin. The completed portions of improvements were initiated for construction under Emergency Relief projects. The project intercepts the run-off from 7 square miles of mountainous terrain and will protect the cities of Tujunga and Sunland. The unit is designed for the probable maximum flood.

Sycamore Wash.-This unit consists of 384 feet of covered reinforced concrete conduit at the junction of Sycamore Wash with the Los Angeles River between San Fernando Road and Southern Pacific Railroad, to provide an outlet for the existing improved channel through the city of Glendale. The unit, including 2,925 feet of improved channel completed under Emergency Relief projects, will receive the run-off from an area of 7.7 square miles in the south portion of the city of Glendale. The channel is designed for 35 percent of the probable maximum flood. Local interests contemplate construction of a relief bypass channel, when required by future development.

Verdugo Wash, Concord to upper Canada bridge. This unit includes channel improvements along Verdugo Wash, consisting of the following features: 4.3 miles of reinforced concrete channel connecting existing improved channels at both ends of the wash between Concord Street and Upper Canada Boulevard Bridge, in the city of Glendale, and the removal and replacement of 15 street bridges, 1 railroad bridge, and 1 footbridge. The unit, including a debris basin and improved channel, above and below the project, completed in part under Emergency Relief projects, and in part by the Los Angeles County flood-control district, will provide protection for the city of Glendale. The channel is designed for the probable maximum flood.

Compton Creek, Alameda Street to Hooper Avenue storm drain. This unit includes channel improvements along Compton Creek, consisting of the following features: 3.5 miles of rectangular reinforced concrete channel from above the mouth of the Hooper Avenue storm drain to below Greenleaf Avenue in the city of Compton; 1,800 feet of rock-paved trapezoidal channel below Greenleaf Avenue; 12 highway bridges and 2 railway bridges. The unit, including 2.5 miles of improvement completed under Emergency Relief projects, provides protection for a large part of the southern portion of the city of Los Angeles and the lowlying area in and around the city of Compton. The channel is designed for the probable maximum flood.

Compton Creek, Hooper Avenue storm drain to Main Street.— This improvement provides for the construction of an open, rectangular concrete channel from Main Street to the upper end of the existing concrete channel (a distance of 2.14 miles). The plan includes the construction of one railroad bridge. The channel is designed for the probable maximum flood.

Burbank Western system (lower).-This unit is located in Los Angeles County, Calif., on Burbank Wash, a tributary of the Los Angeles River. The plan provides for the construction of a rectangular reinforced concrete channel and appurtenant structures, extending from Burbank Boulevard to above Victory Boulevard, a distance of approximately 8,780 feet. The channel is designed with a constant width of 40 feet and with wall heights of 12 to 16 feet. The construction of five highway bridges and of five railroad bridges, and the relocation of five sewer lines and other public utilities are included in the plan. The channel is designed to provide adequate protection from erosion and overflow damage by uncontrolled floodwaters of the Burbank Western system for the residential and industrial properties located in or adjacent to the valley area between Burbank Boulevard and the Los Angeles River.

Santa Fe Dam.-This unit is located on the San Gabriel River, approximately 29 miles above its mouth.

The plan provides for a rolled-fill earth dam 24,100 feet long, maximum height 92 feet above stream bed, with a flood-control basin of 33,000 acre-feet capacity at spillway crest; an uncontrolled spillway 1,200 feet in length, located near the right abutment; and outlet works through the dam near the center of the structure. The operation of the basin will regulate the run-off from a tributary area of 231 square miles, reducing the flow of a design flood from 81,600 to 19,000 cubic feet per second.

San Gabriel River, canyon mouth to Santa Fe Dam.-This unit includes the raising and strengthening of existing levees between the mouth of San Gabriel Canyon and the Santa Fe floodcontrol basin, a distance of 3.5 miles. This unit will confine the probable maximum flood on the upper San Gabriel River to its present course, prevent flanking of the Santa Fe flood-control basin, and will protect the built-up areas in the vicinity of Azusa. San Gabriel River, Santa Fe Dam to vicinity of Walnut Creek.Provision is made for an open trapezoidal dumped rock channel extending from Santa Fe Dam downstream to a point above the mouth of Walnut Creek (a distance of 4.45 miles). The unit is designed for the flood discharge from Santa Fe Dam.

San Gabriel River channel-Walnut Creek to Whittier Narrows flood-control basin.-The plan of improvement provides for construction of a trapezoidal channel from Walnut Creek to Whittier Narrows flood-control basin (a distance of 2.71 miles). The channel is designed for the probable maximum flood.

Alhambra Wash.-This unit includes channel improvements along Alhambra Wash, as follows: 7.2 miles of rectangular reinforced concrete channel to close gaps and extend the channel from Huntington Drive to the Rio Hondo, and 12 bridges, 6 of which

are highway, 2 railroad, 3 farm, and 1 footbridge. The project intercepts the runoff from 14.3 square miles of highly developed area in the cities of Alhambra, Pasadena, San Marino, and San Gabriel. The channel is designed for the probable maximum flood.

Rio Hondo channel-Santa Fe Railway to Whittier Narrows flood-control basin.-The plan of improvement for this unit provides for the construction of a trapezoidal channel from the Santa Fe Railway to Whittier Narrows flood-control basin (a distance of 6.32 miles). The channel is designed for the probable maximum flood.

Rubio Canyon Diversion.-This improvement provides for the construction of a debris basin at the junction of Rubio Flores Canyons and a rectangular concrete channel to divert the flow from the debris basin to Eaton Wash (a distance of 1.17 miles). The debris basin, with a tributary drainage area of 1.82 square miles, has a debris storage capacity of 182,000 cubic yards. Covered sections are provided at street crossings over the concrete channel in lieu of bridges, and 0.75 mile of the channel is a closed box section.

Eaton Wash.-This rectangular improvement provides for the construction of a reinforced concrete channel from the outlet of Eaton Dam to a junction with Rio Hondo (a distance of 7.48 miles). The plan of improvement provides for the reconstruction of four railroad bridges. The channel is designed for the probable maximum flood.

Ballona Creek channel and jetties.-This unit includes channel improvements along Ballona Creek, consisting of parts of the following: 9,273 feet of rectangular reinforced concrete channel between Redondo and Washington Boulevards, 8,800 feet of rectangular concrete conduit with trapezoidal high-water section between Washington and LaSalle Streets, 29,175 feet of trapezoidal rock-paved section between LaSalle Street and the ocean; 2 heavy rock jetties extending into the ocean for approximately 800 feet to insure a free channel at the outlet; 14 highway bridges, 3 railroad bridges, the substructure for a future highway bridge; a temporary highway bridge and a temporary railroad bridge; and large regulating gates at the mouth of Playa del Rey Lagoon, to allow free tidal action within the lagoon. The unit provides drainage for 130 square miles of area in West Los Angeles, and when side drainage channels are provided, will control floods in West Los Angeles, Venice, Culver City, and Beverly Hills. The channel is designed for the probable maximum flood.

Local cooperation.-See page 5 for requirements.

Operations and results during fiscal year-Hansen Dam-New work.-Operations with regular funds, during the fiscal year, consisted of rights-of-way transactions.

Maintenance.-The dam was maintained in good operating con

dition.

The costs of new work were $80,937.21 for rights-of-way and $25,054.15 for maintenance, a total cost of $105,991.36.