THE HISTORY OP THE BALTIMORE WATER SUPPLY SINCE 1882,
E. G. PaIGE.
. INTRODUC'TI W
This paper is not complete in itself and should
not be confused as such. Its only purpose is to complete
the work: started recently by Mr. K. P. Spence who has treated
the subject up till the close of 1872.
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Prom the time of the completion of Druid Lake,
formerly known as Lake Chapman, in 1868 until 1872 there was
no new construction work of any importance. In 1872 the
Inadequacy of the Jones Palls supply became apparent and the
need of an entirely new source was realized. The Gunpowder
River, which had been investigated and discarded in 1857, was
selected as this new supply. Temporary works were erected
and water was pumped over the dividing ridge between the Gun-
Powder River and Jones Palls and thus into Lake Roland, The
capacity of this temporary supply was five million gallons
THE HEW WORKS.
Nothing more was done from the completion of this
temporary reinforcement in 1872 until 1874 when the city
appropriated $4,000,000 to rebuild and complete the Gunpowder
River supply. This money was to build the following works;
To construct a new reservoir, Lake Montebello, with
an area of sixty acres and with a capacity of 500,000,000
To construct an Impounding dam at Loch Raven with
a crest elevation of 170 feet above mean tide and a reserve
capacity of 510,000,000; a tunnel 12 feet In diameter and
7 miles long to connect this dam to Lake Monkebello and
capable of delivering 170,000,000 gallons per day; the con-
struction of a storage reservoir, Lake Clifton, with, a capacity
of 265,000,000 gallons and the laying of a 40 inch main from
Lake Clifton to the city limits.
This work was completed and in 1881 about three-
eights of the city's water supply was received from Jones
Palls; the new Gunpowder supply furnishing the remainder.
T^e Mount Royal Pumping Station, located at Uorth
Avenue and McMechen Street, and built in 1889, is the one
remaining steam plant at the present time.
The Eastern Pumping Station was also constructed in
1889 and is located on Oliver Street west of Wolfe Street.
This station was built originally as a steam plant but was
converted in 1915, when motor driven centrifugal pumps were
With but very few changes and improvements the supply
remained in this state until 1908.
In 1907 it was realised by the Health Department that
the typhoid cases in Baltimore were due to the water supply.
The growing dissatisfaction with the water supply lead, in
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1908, to the floating of a bond -issue of $5,000,000 to in-
crease and perfect the water supply. This appropriation was
to carry out the following improvements:
A new dam some 240 feet above the old dam, designed
for a crest elevation of 235 feet and only carried to an ele-
vation of 188 feet above mean tide; the erection of a filtra-
tion plant near Lake Montebello with a covered reservoir for
the filtered water; and the construction of Lake Ashburton in
the northwestern section to supply the western section of the
During 1910 the need for this increased siipply became
imperative. For six consecutive months the flow of the Gun-
powder River was less than 75,000,000 gallons per day, and
during one month it dropped as low as 54,000,000 gallons per
Throughout this period there was a water famine in
the city. The water coning from the Gunpowder River was muddy
and in its unfiltered condition was unfit for use. Every
home was equipped with a filtering device of some kind and in
many sections of the city the water was of such condition that
it could not be used at all.
The many springs throughout the city were practically
the only sources of drinking water available. Tolson Spring
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located on Harlem nvenue just west of Pulaski Street,
furnished the drinking water to thousands of people living in
a radius of several miles. Several springs in Druid Hill
Park also furnished great numbers of people with water.
People waited in line at these springs night and day for their
personal supplies. Young children hauled water from the
springs to different sections of the city and sold it to those
who could not go after it.
The recurrence of such a condition at the present
time, when the daily consumption is between 90 and 100 million
gallons, would prove a calamity to the city.
In 1911 the purification was begun by treating the
water with calcium hypo -chloride. Immediately following this
action there was a marked decrease in the number of typhoid
cases in the city.
THE LOCH RAVEN DAM.
Loch Raven Dam is located 7 miles north of the
Montebello Filters, and as constructed in 1915, was built
with a crest elevation of 188 feet, but with a base sufficient-
ly wide to permit the ultimate raising of the crest to 270 feet.
This is somewhat wider at the base than the original plans
called for as mentioned above. Soon after completion the
crest was raised an additional four feet by the construction
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of "tipping sections" made of wood and steel. These sections
were so arranged that when the water reached an elevation one
foot above the crest, some of the sections tipped, allowing
the water to flow over the masonry crest. When the water
receded the sections automatically tipped back into position.
Water is conveyed from the Loch Raven Dam to the
Montebello Filters through about J mile of 10 foot cement-
lined steel pipe, and six and one-half miles of 12 foot
tunnel cut through solid rock. Some portions of the tunnel
are unlined, some are lined with brick and others were re lined
with reinforced concrete in 1914.
The Montebello low lift Pumping Station is circular
and contains 5 centrifugal pumps located in a pit upon
foundations 23 feet below the ground level. These pumps have
an aggregate capacity of about 250 million gallons per day.
Each pump is of a different capacity and advantage is taken
of this fact in securing the most economical combination
necessary for the volume of water required. It is interesting
to note that this station is operated by three shifts of 8
hours each, one man to a shift,
After leaving the pumps the water passes through a
venturi meter into the mixing basin where alum is applied as a
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coagulant in order to prepare the water for filtration. It
next enters the coagulating basins where the heavier particles
and much of the "bacteria are removed. There are two of these
basins of 8,000,000 gallons capacity each.
The water next floY/a to the filters of which there
are 32, each having a normal capacity of 4 million gallons
per day. The filtering medium is sand 24 inches deep, sup-
ported on a well graded gravel layer 14 inches thick. The
net sand area of each filter is 1,440 square feet. The
filters are washed at intervals varying between 15 - 50 hours
by reversing the flow through them for a short time.
The filters are located above basins directly
connected with the filter reservoirs, which have a combined
capacity of 17,000,000 gallons. The application of liquid
chlorine to the water as it enters the filtered water
reservoir Is the last step in the process of purification.
T^e completion and placing in operation of the Loch
Raven Dam, the tunnel and the Montebello Filtering Plant
brings the water supply up to the present day. The Jones
Falls supply has been abandoned, but can be used to supply
unflltered water when an emergency arises.
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THE NEW DhM
In 1919 due to the annexation of a large amount
of land by Baltimore City it became imperative to increase
the supply of the city. The possibility of a recurrence of
the dry spell of 1910 and the disaster such a drought would
cause, had been realized for years by engineers of the Water
Department. After much controversy the crest of the Loch
Raven Dam was raised. T^is created a reservoir of 23
billion gallons capacity. The work, completed in 1923,
consisted of raising the crest 52 feet above its former level,
the original foundation being used. The new structure is of
concrete, of the gravity type, and has an Ogee spillway 300
feet long, and a total length of 625 feet.
The raising of the dam at Loch Raven would subject
the tunnel to a hydro-static pressure far in excess of its
safe limit. C ntrol by means of the gates at Loch Raven,
however, was impossible, as too wide an opening would subject
the tunnel to pressure, and too small an opening would cause
the pumps to lose suction.
This difficulty was obviated by building a small
balancing reservoir near Loch Raven. This reservoir was
created by building a small earth dam across a ravine, with
a spillway at an elevation of 200 feet, and sinking a shaft
in the middle of this reservoir to the existing tunnel so
that water can flow in and out freely. In operation, water
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is admitted to the tunnel through partially closed gates at a
rate near that calculated to meet the needs of the city.
Should the city need more water the difference would be made
up from the balancing reservoir and if less water is needed
than that passing the gates, the excess water would escape
into a nearby stream. It is thus possible to maintain the
tunnel under a safe and practically uniform pressure.
The power for operating the pumps is transmitted
from the Monument Street power house, where connections are
made with the transmission lines from McCall's Ferry Hydro
Electric Plant or from any of the local generating stations.
One of the difficulties with operating the pumping station
with power received over long distance lines is that there
are occasional interruptions In the service. On such
occasions all the pumps are thrown out of service, the sudden
stoppage causing water hammer due to the sudden checking of a
column of water 7 miles long and 12 feet in diameter. This
effect is lessened by the balancing reservoir acting as a
safety valve; also a shaft has been drilled to the tunnel at
Montebello. If there is a sudden surge of water in the tunnel
due to the sudden stoppage of the pumps this shaft will over-
flow and discharge into the wash water reservoir.
In connection with the new dam the entire water shed
of the Gunpowder River, which comprises 306 square miles, is
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under city supervision and all streams are also watched by
city inspectors. The city now owns about 5,000 acres lying
along the different streams and has absolute control of both
banks of the river as far north as Phoenix, about 19 miles
north of B a ltimore. The city inspector systematically visits
every premise on the watershed and eliminates many of the
nuisances which would cause impurities entering the river.
Baltimore County is full of hills and many of them
are covered with clay which at times of heavy freshets is
washed Into the river. such water Is difficult and costly
to treat. In order to retain the water in the earth and
prevent erosion the city has planted over a million trees
and the planting will be continued until all the city ground
Due to the difference in elevation of the different
sections of the city it has been necessary to divide dis-
tribution into three zones: Low Service, Middle Service and
The Low Service Zone, which Includes all territory
below the 100 foot contour, Is supplied by gravity from the
reservoir at Montebello. This gives a variation in static
pressure between 49 and 92 pounds in different sections of
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this Z ne. T^is Zone consumes about 65$ of the city's
The Middle Service Zone is divided into two parts
the Eastern and Western Middle Service Zones, The Eastern
includes all territory East of Jones Palls Valley which lies
"between elevations 100 and 250 feet. This Zone is served
from Guilford Reservoir and has pressures varying from 39
pounds to 104 pounds. The Western includes all elevations
100 and 300 feet. This Zone is supplied from Ashburton
Reservoir and the pressures vary from 22 pounds to 108 pounds.
The water consumed in the Middle Service Zones is about 32$ of
the total consumption of the city.
The High service Zone is also divided into Eastern
and Western sections with the Jones Palls Valley as a boundary.
The Eastern High Service includes territory lying between 250
and 350 feet contours and is supplied by the Roland Standpipe.
The static pressures vary between 86 and 43 pounds. The
Western High Service Zone includes all territory lying between
the 300 and 400 feet contours and is supplied from the Arling-
ton Standpipe. The static pressures vary between 65 and 108
pounds. The High Service accounts for about 3$ of the
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For several years the Filtration Plant at
Montebello has been overtaxed and with the acquisition of
the new territory in 1919 and consequent expansion of the
distribution system it has been found necessary to increase
the capacity of Montebello Plant. This work was started in
1925 and is now nearing completion,
A new plant is being constructed on the west side of
Hillen Road directly opposite the old plant. This new plant
is practically the same in construction as the old plant and
holds 28 filters with a 24 hour rating of 4,000,000 gallons
each. This will bring the combined capacity of the two
plants up to 240,000,000 gallons per day.
The new filters are of wood slat base, 1 inch
boards spaced 1 inch apart being the supporting medium for
the gravel and sand beds. This is a departure from the pipe
base of the old plant.
An alum manufacturing plant is being constructed in
the building to obviate the necessity of buying the alum and
chemicals for treatment.
The completion and placing in service of the new
Montebello Filters will bring the water supply of Baltimore
up to the present time and concludes the History of the Water
Supply of Baltimore,
All material for this thesis was taken from the
1, An Article written in recent years by
V. Bernard Si ems, recently Chief Engineer of Baltimore Water
2, Personal notes of Mr. Hopkins, present Chief
Chemist of Montehello Filtration Plant,
3, An Article written by J. W. Armstrong,
Filtration Engineer of Baltimore Water Department.
The present dam at Loch Raven 1 9 -1
The Loch Raven D ,m in 1919
The new Filtration Plant at T'ontebello
Coagulating Basins of the Hew Filtration Plant
Coagulating Basins of the Old Filtration Plant