Excellent Condition of the Water Department of Portland

Excellent Condition of the Water Department of Portland

Ownership.—Works owned and operated by the municipality supply all closely built territory within the city and two outside municipalities; the original works, started as a private company about 1857, were purchased in 1887, since which time the present supply works were built and practically the entire distribution system laid.

Organization.—Control of the water department is by Commissioner of Public Utilities John M. Mann, who took office for a four-year term July 1, 1917. D. D. Clarke, chief engineer, has been associated with the works since 1893 and is a member of the American Society of Civil Engineers and other technical societies; F. M. Randlett, principal assistant, is an associate member of the first. L. S. Kaiser, superintendent, has been with the department twenty-four years. There are 180 regular employees; all except the chief engineer and the superintendent are under civil service.

Quarters.—The main office is in the city hall, Fourth and Madison streets, with branch offices on the east side at East Seventh and Alder streets and on Sacramento street near Williams avenue. The meter shop is at Fourth and Market streets.

General Outline of System.

Supply by diversion from Bull Run river, about thirty miles east of Portland, flows by gravity through two steel conduits to reservoirs within the city on each side of the river, and is distributed by gravity from them to six principal services, with nine higher districts supplied by pumpage and several lower sections under reduced pressure. In reserve is a pumping station on the Willamette river, connected to the low gravity service on the west side. Elevations in this report are above city datum, which is 3.13 feet below mean low water at Astoria.

Supply Works; Bull Run River Supply (General).—Developed in 1894 by constructing diversion works on the river about thirty miles east of the city, and a gravity flow-line to the distributing reservoirs; a second flow-line was added in 1911. The water-shed originates in the Cascade mountains, has an area of 102 square miles, is characterized by steep slopes along the water courses, densely and completely wooded, entirely uninhabited and is included in a United States forest reserve. Gagings made from 1895 to date show an average run-off of 560,000,000 gallons a day. with a minimum month at the rate of 53,500,000 gallons a day, and a minimum day of 46,500,000 gallons. Headworks.— The headw’orks are located on the south bank of the river, from the bed of which a canal, 15 feet wide and 3 feet deep, extends 400 feet along the bank of the river; it is excavated into the bank and formed by rubble masonry walls, with the outer wall acting as a waste weir; it terminates in an enlarged section forming a forebav with walls rising above high water and enclosing a screen chamber and sump covered by a wooden gate house, controlling the flow into the conduits. The water level in the canal is maintained at about elevation 717. Supply Conduits.—The supply is conveyed from the headworks through two conduits mostly parallel and laid an average distance of 25 feet apart; the conduits cross each other at five points, but there are no cross-connections. The older conduit, laid in 1894, is riveted steel and 24.30 miles long, and has a capacity of 22,000,000 gallons a day. The newer conduit, laid in 1911, is lock-bar steel and 24.76 miles long, and has a capacity of 43,500,000 gallons a day. Both follow the profile of the ground, have a 3-foot cover except at river, marsh and gully crossings, and are well equipped with air valves, blow-offs and manholes. Bull Run river is crossed at two places and Sandy river at one, the conduits being supported on substantial steel truss bridges of 100, 200 and 300 feet span, respectively; several shorter sections are carried by iron trestles on concrete piers over gullies and swampy land. Where laid above ground the pipe is surrounded with sawdust and securely boxed. The older conduit terminates in reservoir 1 and the newer in reservoir 5, with a 30-inch by-pass, to reservoir 1; a short 3×5 1/2-foot reinforced concrete tunnel connects the two reservoirs. Both conduits discharge their full capacity into the reservoirs, the excess over the city’s requirements wasting to sewers. An 18-inch main 0.6 mile long connects reservoirs 1 and 2 and a short 36-inch main reservoirs 5 and 6, with a 30-inch by-pass across the last A 32-inch cast-iron conduit from reservoir 1, with a 30-inch connection from reservoir 5, extends about six miles westerly to reservoirs 3 and 4, across the Willamette river. It has a 24-inch emergency connection to a 24-inch eastern low gravity main near reservoir 2; a 4-inch connection to a 6-inch main on the same service one-half mile east of the Willamette river; a 16-inch connection to a 24-inch western low gravity main, and a 12-inch connection to an 18-inch western high gravity main. At the Willamette river crossing it branches into two parallel lines of lap-welded steel pipe 600 feet apart.

*Excerpts from ttie report on Portland. Ore., wster and fire conditions by the National Board of Fire Underwriters.

Willamette River Supply in Reserve.— Supply works, located on the west bank of the Willamette river, about five miles south of the congested value district, have been held in reserve since 1894, having been “used only once, for three days, when the 28-inch river crossing broke in 1909.

Reservoirs and Standpipes.—Reservoirs 1, 3, 4 and 5 are similar in construction, formed by concrete or masonry dams across natural ravines, with sides lined with concrete. Reservoir 2 is built partly in excavation with embankment on all sides and has brick masonry lining covered with asphalt; reservoir 6 is similar but has concrete lining and dividing wall coming to within 3 feet of high water mark. At each of these reservoirs is a large, substantial gate house containing control tank to which are connected well gated inlet and outlet pipes; in addition all the gate houses but the one at reservoir 4 contain weir chambers for measuring the influent; the inlet and outlet pipes of reservoir 5 are laid in tunnels on a steep hillside. At reservoir 2 a portion of the supply is bypassed through a Pelton wheel to drive the Mt. Tabor pumps. Supply line from reservoir 3 to reservoir 4 passes through City Park pumping station, the 63-foot head being used to operate Pelton wheels, but the station may be by-passed or reservoir 4 fed direct from the 32-inch supply line through a 20-inch connection. The Vernon, Burlingame and Council Crest standpipes are of steel, well anchored to substantial concrete bases. The Portland Heights and St. Johns reservoirs are built in excavation and lined with concrete. The other nine are reinforced concrete tanks built mostly in excavation.

Pumping Stations of the Distribution System.

City Park Station.—Located on the west side in the City Park, between reservoirs 3 and 4. The largest pump is ordinarily used to supply the western low pumped service, and the other may do so in emergency. The smaller water-driven pump is ordinarily used to supply the western high pumped service and the electrically operated pump is held in reserve. Electric power is obtained from the Portland Railway, Light and Power Company. The pumps are housed in a small concrete building with frame-partitioned office. Lincoln Street Station (In Reserve).— Located at Lincoln street and Broadway on the west side; built in 1891 and formerly used in connection with the Willamette river supply. Has been held in reserve since 1894, except for three days in 1909 when the 28-inch river crossing broke and for twenty-seven days in 1915 when the City Park reservoirs were being repaired. Supplied through the western low gravity service and supplies the western high service, with the larger pump also connected to supply the western low pumped service. Other Stations.—The five other stations supply small outlying residential districts at high elevations; each has equalizing reservoir or standpipe. The Mt. Tabor pumps are housed in the gate house of reservoir 2 and are driven by a Pelton wheel. The others are electrically operated with power obtained from the Portland Railway, Light and Power Company; operation is automatic, but each station is visited daily by a department employee.

Consumption.—The average daily consumption for the entire city, subdivided into the more important services, for the year ending November 30, 1916, in gallons, was as follows: West Side—Low gravity service, 7,300,000; high gravity service, 2,074,000; pump services, 587,000. East Side —Low gravity service, 2,704,00|0; intermediate gravity service, 3,020,000; high gravity service, 2,270,000; Vernon standpipe service, 3,790,000. Entire city, 21,745,000. The installation of Venturi meters on the supply lines from the reservoirs and force mains from the pumping stations was completed early in 1916, previous to which there were no accurate records of consumption. Maximum.—Consumption is greatest during the summer, due to lawn and street sprinkling. In 1916 there were twelve days when the total consumption exceeded 30,000,000 gallons a day; the maximum day was June 17, when 36,500,000 gallons were used in the entire city and 8,710,000 gallons in the western low gravity service, which includes the congested and other high value districts, and where the per capita rate is over three times as great as for the remainder of the city.

Pressures.—Recording pressure gauges are maintained on the six gravity services. Pressures are in general well maintained, and on the west side show a smaller daily variation than in 1910. In the eastern intermediate gravity and Vernon standpipe services, at points distant from the source of supply, the drop during sprinkling hours averaged 14 and 18 pounds, respectively.

Distribution System.

General.—Distribution to the major portion of the city is by gravity in six main services supplied by reservoirs or standpipes on either side of the river; no connection is provided between services on the east and west sides, but there are a number of emergency connections, mostly of small size, between other adjacent services. Nine small areas at high elevations are supplied by pumping; each has an equalizing reservoir or standpipe.

Western Low Gravity Service (General). —Supplied from reservoir 4, elevation 229, with emergency supply from the Palatine Hill pumping station; connections to the western high gravity service are only fairly numerous and are nearly all small. The service comprises the major portion of the closely built area on the west side and includes the congested value district and high value manufacturing, warehouse, minor mercantile and residential districts, with long narrow sparsely built extensions up and down the river. Elevations range frcm 30 to 170, but are mostly below 120; in the congested value district, the range is from 29 to 92. A single 30-inch main extends from reservoir 4 to the distribution system. It passes through the center of the congested value district and continues about 9 1/2 miles almost to the northwestern limits of the city. The secondary feeder system is extensive and well gridironed and looped; connection is made to the Palatine Hill pumping station through a 24-inch and a 30-inch main, which act as feeders to the southern end of the service; the former has an emergency connection to the supply line connecting reservoirs 1 and 3. Minor Distributers. — Hydrant supply in many localities is from secondary feeder mains, the length and proportion of mains supplying hydrants in the congested value district being shown in the accompanying table:

Western High Gravity Service (General). —Supplied from reservoir 3, elevation 299, with emergency supply from the Lincoln street pumping station. The area covered ranges in elevation from 100 to 260, but is mostly below 220, and is principally of residential occupancy. Mains.—A single 18inch main extends from reservoir to the distribution system with a 12-inch emergency connection to the 32-inch supply line connecting reservoirs 1 and 3; a 10-inch branch supplies the northern part of the service, and a second branch, 12 inches in diameter, extends to a 12-inch loop from which a 10inch main continues to the southern limits of the service; the grd iron consists of 4, 6 and 8-inch mains and is of fair strength.

Western Low Pumped Service.—Consists of two small residential sections in the northwestern and southwestern parts of the city supplied, respectively, by the Willamette Heights tank, elevation 446, and the South Portland reservoir, elevation 475. Supply is pumped from the City Park station to the first section through a main consisting of 1 1/2 miles of 10 inch and mile of 6-inch, and to the second through a 6-inch about 3½ miles long. Elevations range from 180 to 460.

Western High Pumped Services.—Consists of two small residential sections northwest and south of the City Park pumping station, supplied, respectively, by the Kings Heights and Portland Heights reservoirs, both at elevation 865. Supply is pumped from the City Park station to the first section through a force main consisiting of 1-3 mile of 12-inch steel and 2-3 mile of 10-inch cast-iron. The second section is supplied through a 12-inch wrought-iron force main, 1 1/2 miles long. Elevations range from 450 to 800.

Western Minor Pumped Services.—The Burlingame standpipe, in the extreme southwestern part of the city, is supplied through a 10-inch force main 3/4 mile long from the Fulton pumping station and supplies several 6-inch and 8-inch lines in which the pressure is reduced. The Council Crest standpipe is supplied through a short 6-inch force main and supplies a short 3-inch pipe which feeds a system of 4 and 8-inch mains south of Portland Heights. The Upper Whitwood and Upper Linnton reservoirs are supplied through short 6-inch force mains and supply a few 4, 6 and 8-inch mains, with pressures reduced as required. These services are all small, outlying residential areas.

Eastern Low Gravity Service.—Supplied from reservoir 2, elevation 229, near which is a 24-inch emergency connection to the 32-inch supply line, connecting reservoirs 1 and 3, with a second connection near the center of the service; there are also numerous emergency connections to the eastern intermediate gravity service. The service comprises a moderately large area east of the river in the central and southern parts of the city and includes mercantile. manufacturing, warehouse and residential districts. Elevations range from 30 to 120.

Eastern Intermediate Gravity Service.— Supplied from reservoir 6, elevation 305. There are comparatively few emergency connections to the high gravity or Vernon standpipe services. The service covers a large area in the north central portion of the east side and is almost entirely residential in character. Elevations range from 80 to 240.

Eastern High Gravity Service.—Supplied from reservoirs 1 and 5, elevation 412. The service covers a large area in the eastern part of the city, entirely residential in character, nowhere closely built and containing large vacant areas. Elevations range from 160 to 330. One section in the southern part of the service has pressure reduced through a regulating valve.

Vernon Standpipe Service.—Supplied by gravity from the Vernon standpipe, elevation 344, and through a regulating valve on an 8-inch connection to the 24-inch high gravity main. The service comprises the northern portion of the east side, is of large area, mainly residential with some small minor mercantile districts. Elevations range from 40 to 240. In St. Johns and two other areas of small size near the northern limits, pressure is reduced through regulating valves.

Tabor Heights Service.—Consists of a small residential section in the east central portion of the city, supplied by the Mt. Tabor reservoir, elevation 590. Supply is raised by pumps in the gate house of reservoir 2, through a 6-inch force main, one mile long. Elevations range from 330 to 510.

Pipes.

Length and Age.—Cast-iron pipe only has been laid for some years; 8-inch is the standard minimum size laid for hydrant supply, but 6-inch is used for short lengths and in special locations. About 3 per cent, of the total amount of pipe in service is thirty years old; less than a fifth is twenty years old and slightly more than a half has been laid since the previous inspection in 1910. All pipe is laid by the department. Condition and Cover.—Cuts made by tapping machine show no pitting or tuberculation, and only in a few cases slight incrustation. Dead ends are flushed regularly; little sediment was discharged during fire flow tests. Small pipes are laid with a 3-foot cover; maximum frost penetration 12 inches.

Gate Valves.

Gate valves arc of various makes. Nearly all open to the right. Present practice is to use geared valves set in manholes on mains 16 inches in diameter and over; smaller sizes in paved streets have standard iron boxes; others have wooden boxes with iron covers. Locations and Spacing. —Valves set in recent years are on property lines at street intersections. In the congested value district the average length of main that would be cut out in case of a break is 795 feet, with 10 lengths out of 89 in excess of 1,500 feet and a maximum of 2,510 feet. In a representative residential district of recent development the average spacing is 925 feet, with four lengths out of 86 in excess of 1,500 feet and a maximum of 2,540 feet. The average spacing on main arteries is about 3,000 feet.

Hydrants.

Number and Type.—On November 30, 1916, there were 5,138 hydrants in service; all are of the post type, set on gated connections to main, with uniform operating nuts and, except a few on the east side, opening to the right. How Located.— Hydrants are set inside the curb or near property line, well protected from damage and free of obstructions. Location of new hydrants is ordinarily determined by the water department; requests of the chief of the fire department for additional hydrants are complied with. Distribution.— The average linear spacing of hydrants and cisterns in the congested value district is 150 feet and the average area served by each is 38,000 square feet; four feet intersections have no hydrants. In a representative residential district of recent development the average linear spacing is 480 feet and the average area served by each is 141,000 square feet. Hydrants are used indiscriminately for street sprinkling and flushing and for flushing sewers. Contractors may use hydrants by obtaining permit and paying water or fire department employee to operate hydrant.

Recent and Contemplated Improvements.

The department has laid an additional supply conduit of lockbar steel 44 and 52 inches in diameter, with a capacity of 43.500,000 gallons a day, from the Bull Run headwords to Mt. Tabor. Reservoirs 5 and 6, having capacities of 50,000,000 and 75,000,000 gallons, respectively, have been completed and put in service. The former is connected with reservoir 1 by a 3 1/2 and 5-foot reinforced concrete tunnel and is the terminus of the new conduit. The latter is used to supply the intermediate gravity service, a new service supplying a large area in the north central portion of the east side, formerly included in the low gravity, Vernon standpipe and Sunnyside services, the last of which has been abandoned. Four small pump services on the west side have been established. A number of large Venturi meters have been installed so that now there are available accurate records of consumption for the entire city and for each service. The 32inch conduit between reservoirs 1 and 3 has been provided with an additional river crossing, 30 inches in diameter; the 24-inch has been relaid at a greater depth and the 28-inch removed and stored for future use. Two emergency connections from the 32inch have been installed on the west side, a 16-inch to the western low gravity and a 12-inch to the western high gravity service. The department has proposed a large number of 12 to 24-inch mains. The building of an additional reservoir on the west side to store 50,000,000 to 100,000,000 gallons is contemplated.

Conclusions.

Organization.—The department is well organized, with competent and experienced officials, and is under civil service regulations. Plans and records are accurate, complete, up-to-date and stored safe from fire. The fire service and emergency operations are unsatisfactory, as employees could reach fires to co-operate with the fire department only after considerable delay.

Supply Works.—The Bull Run river watershed is ample for the needs of the city and headworks are substantial. The duplication of supply conduits is an excellent feature, but the numerous points where the conduits are in close proximity introduce a slight element of unreliability. The Palatine Hill pumping station is a valuable reserve.

Distributing Reservoirs.—The total reservoir capacity is equal to ten hours fire flow and five days maximum consumption Seven-eighths of the total storage is on the east side, making the supply to this section particularly secure. The west side reservoirs, however, after deducting a reasonable fire flow, contain less than two days maximum consumption for the districts they serve; the high values found in this section amply justify increased storage as contemplated by the water department. The distributing reservoirs are of substantial construction, carefully maintained and at good elevations. Consumption.—Consumption is moderate; it could be somewhat reduced, particularly during sprinkling hours, by the more general use of meters. Pressures.—Pressures are good and are well maintained under normal consumption; they are adequate for automatic sprinkler supply in the congested and other high value districts. Mains.—Although the regular supply to each service is mostly through single mains, the large number of emergency connections between adjacent services and from the 32-inch conduit to the west side gravity services, together with the force mains from the Palatine Hill pumping station, do not make duplication of the supply mains particularly necessary at present. Cast-iron mains are in good condition and free from deposits; the larger steel and wrought iron mains have been in service over twenty years, but appear to be in good condition. Gate Valves.— Valve spacing is rather wide in all parts of the city, especially on main arteries; regular inspections are made and valves maintained in good condition. Hydrants. —Hydrant spacing is good in the congested value district, but wide elsewhere; most are of good size and type; regularly inspected and in fair condition.

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