Evening star. [volume] (Washington, D.C.) 1854-1972, 1909-08-26
Maj. Morrow Speaks Well of
Washington Aqueduct.
REPORT ON WATER SYSTEM
Condition Excellent and No Neces-
sity for Additional Plant.
CARRYING CAPACITY AMPLE
Recommendations Made for Com
pleting the Installation of Meters.
Resume of Conditions.

According to Maj. Morrow. tho en-
Eineer officer In charge Of the District
w0ter-suppfy system. the Warrington
aqueduct, after fOrty-six years Of serv-
ice, Is I'm excellent condition. and there
is necessity for any additional
source of supply to meet the demands
Of the immediate future.
Maj. Morrows annual report on the sub
ject was made public at the War De-
partment today. 1t contains a mass of
information in regard to the aqueduct
| increasing and improving the water sup
piled to the residents of the District
The main portion of the report is de-
voted TO a description of the conduit from
Great Falls and the various auNilaries
of the filtration plant. He says that the
conduit between the gatehouse al Great
Falls and the north connection of the
Dalecarlia. or receiving, reservoir was
drained. cleaned and inspected twice dur
ing the past year.
That section of the conduit is about nine
miles in length. 1t is generally lined
with brick, having an internal diameter
of nine feet. There are, however, several
places where the conduit was blasted
through solid rock. where no brick lining
has ever been placed.
Maj. Morrow says the outline OF the
conduit at those places is rough and ir-
regular and is considerably larger in sec
tions than are the lined portions. The
feeder between the dam and gatehouse
Esoll ri during
the year and was found to be in good
condition with the exception of leak
under the stop logs which. it is stated,
will be repaired this summer.
Crosses Twenty-six Valleys.
The conduit is carried across twenty
six valleys on four bridges and twenty
two fills with culverts. "As a general
rule says Maj. Morrow. 'the conduit.
after forty-six years, service. is in excel
tent condition. The brick lining is almost
invariably strong and sound. 1t is only
at the first of the unlined sections. and at
the bridges and culverts, that any mate
rial deterioration has occurred. 1t was
only in the fourteen -hundred-foot section
between Great Falls and waste weir No.
1 that any considerable decay of rock
was noted. In that section it appears
that the rock becomes dislOdged in the
greatest amount only in a section of
about 400 feet in length north of and
near waste weir No. 1. Outside of that
section there has been little falling Of
rock from the roofs and sides of the con-
duit since construction, about forty-six
years ago.
According to Lieut.. w. r. Hannum,
the vertical diameter in the section where
the rock is most liable to decay appears
to have been increased not more than five
feet, and it may be that when sufficient
rock shall have fallen. so that the roof
will be above the level of the flowing
water, thus preventing wash of the seams
the rock will cease to break off. Further
water, thus preventing wash of the seams,
now washed in certain places, can be pre-
vented by filling with cement mortar
II do not anticipate any sliding or any
fall of rock of sufficient magnitude to cut
off seriously interfere with the sup
ply of water. To guard against any pos
| sible danger, the section where the rock
| is liable to decay should be lined. That
this would be very difficult to do under
present conditions is evident, but il is
not believed to be absolutely impossible.
although to do so would require excep-
tional expense for such work and con-
siderable time
Method of Averting Danger.
1t is believed that dangerous overtop-
ping of the fill may be prevented by keep
| ing the culverts properly cleaned and II
possible altering the stream bed above or
below the cuvert in order to reduce the
deposits of sediment in the culvert and
increase the velocity of flow through the
culvert. At certain points along the line
of the conduit where it crosses ravines
of earth fills these fills since the construc-
| ton of the conduit have shrunk, with. q
consequent reformation OF the conduit 1t
is believed that this reformation occurred
within comparatively short time after
the conduit was constructed, and that the
reformation has at present reached it's
limit.
| 1T is believed that there is no danger
| from further settlement, but there may be
danger from a leak starting through the
rubble lining of the conduit and the earth
lembankment outside. To prevent this
possibility, 1t has been proposed. and ma
terial has been purchased to line culvert
No. 20 which shows the greatest deforma-
tion with cement mortar lining, REIN
forced by a type of wire cloth.
/ 1T has been noted that the mortar in
the brick masonry in the lined sections Of
the conduit IS inferior to our present day
Portland cement mortar, but at no point
has it been observed that the mortar has
been washed out of joints between the
bricks to an extent to cause any appre-
| hens;on.
1.-The loose bricks, occurring at several
places at the invert of the conduit, occur
red, according to my recollection. only In
those sections OF the conduit crossing the
earth fills mentioned above. This may be
explained by the fact that the settlement
of the conduit, causing a shortening of
the vertical diameter and the lengthenins
of the horizontal diameter of the conduit,
would cause a crack along the crown and
also along the invert of the conduit, max
ing ii possible for the water to easily
wash out the mortar between the joints
OF the bricks in the invert.
Test of Carrying Capacity.
In order to test the maximum carrying
capacity of the aqueduct and to determine
the loss of head at various rates of the
flow in the several sections, some expert
mental work was done in November OF
this year. The reservoirs were first drawn
down TO about the elevation they would
assume at the calculated maximum; the
Continued on Ninth Page)