The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1890-03-07
AN EXPERT OPINION.
Mr.. Williams Plans From IN
Engineers Standpoint
THEIR DETAILS DISCUSSED.


ts1S Heaalng OF spring ILL cAp{aYs tAAs
appeared in yoar issue Of the Alb inst. Is
awarding to the mayor. council and cit
GEMS Of Seattle TO bessir themselves in the
matter OF water supply.
II was the general opinion in June last.
when the ire took place. that the small
bore OF the main was the real cause OF the
vaser supply giving out: 1t was not gen.
orally known then that the engine power
II Lake Washington Was inefficient. that
the reservoir was too small, nor that the
mains leaked We have practically re-
eeived notice from the manager OF the
Spring Hill Water Works to provide for
ourselves. - his company is no longer
able TO meet the demands made on them
for water.
Almost Immediately after the FIRE the
mayor and council Of this city took
steps to get reliable information as 10 the
Introduction Of an ample water works sys-
TEN for the city. and the services Of Mr..
Bene1ette Williams were engaged, upon
the recommendation OF the mayor Of
Chicago. Mr.. Williams was requested 10
draft scheme on water works for the city.
He has already Published his report His
plan, rs you are aware, Is briefly ~ fol-
lows: A dam Is TO be thrown ACROSS Cedar
river at point where the altitude of the
water In the river viii b 53a feet shove
high water mark at Seattle; thence he
trains the water through fume TO Swan
Lake, which Is to be used as IN impound-
ing basin with . water level of 435 feet
above high water mark. From this re-
serve two reservoirs ia the neighborhood
III the city win be fed. These reservoirs will
have respectively an elevation OF 400 feet
anu 30 feet above high water mark. and
are intended TO supply high and low level
district throughout the city. Having heard
many criticisms upon Mr.. Williams
scheme. and knowing the urgent need of .
good water supply for the city. took the
pains TO seek information on the subject
Every engineer knows how difficult il is to
form an opinion upon mere report. with
out engineering data, so | called on Mr..
Williams and asked for information. He
kindly gave me access to all his maps and
working drawings. l have thus had an
excellent opportunity to study the matter
thoroughly and to form an independent
opinion on the question of water supply for
the city. As This Is pubic subject, told
Mr.. Williams that intended to discuss it
freely.
As regards other schemes the only one
We need notice IS that known as the valley
route, supposed to be advocated by COun-
Gilman White and others. These gentle
men presume water can be brought in
pipes direct from Cedar river with advan-
tage, ct lower cost Mr.. Williams effec-
tuaily deals with this method In his letter
that appeared in your columns OF the I'd
inst 1t is simply necessary to bear in
mind that this plan does not provide q
safe and lasting supply OF pure water; that
In case of accident to the dam the whole
system would break down. This element
Of risk alone would deter an engineer from
adopting 1t.
Allowing even that the river dam held.
the water above il would be turbid
and discolored during food seasons
and the solid matter held in suspension
would enter the mains. which, not having
an even grade to their outlet, would as
suredly become choked. Again, the course
proposed subjected the pipes to enormous
hydrostatic pressure in places. This would
necessitase the use of iron pipes. Here.
however. another difficulty arises, which
the advocates of iron versus wood have
not thought OF. Iron pipes OF the neces-
sary dimensions. viz. As inches in diane
ter. say IN iengths OF u feet. would weigh
with tianges about tons apiece. How are
these TO he delivered along q rough clear
ing through the bush7
This difficulty could not be overcome by
the use OF several pipes OF smaller dame
ter. For example, say the head of water
divided by the length of the pine was
LOO, then ppe 80 inches in diameter
would supply s.699 gallons per minute and
would weigh in 12-foot lengths OF inch
metal 3, is7 pounds. II instead Of using
single pipe of 30 inches in diameter, sew
eral pipes Of 10 inches in diameter were
used. the result would be this: The dis
charge Of o single io-inch pipe under the
same circumstances would only be 219
gallons per minute. and would weigh, IL
msde OF 9-i6 inch metal in ia-foot lengths,
Cos pounds. II would take eighteen OF
these i0inch pipes to provide the place Of
the S-inch pire, and their collective
weight would be i2.0e4 pounds, nearly
three times The weight of the single length
OF Seinch pipe. These examples prove
the absolute necessity OF avoiding great
hydrostatic pressure in very long conduits
of large diameters. particularly across
rough country 30 that wooden pipes or
froughing may bs used in place Of iron
pipes.
These remarks do not refer TO the use of
cast iron mains laid under the streets of
cities for disseminating water under
pressure; they apply only to the large
conduits used in supplying reservoirs from
sources NJ . great distance. where il Is
expedient 10 use even . greater length Of
conduit to avoid pipe pressure from
within
hK sFSzFTTE WILLIAMS scHFME
The fume adopted by Mr.. Williams
illustrates nav former argument. II was the
method used by the Egyptians. Romans.
Chinese and Others who were unable 20
manufacture pipes capable OF resisting
internal pressure. So they brought water
from long distances in aqueducfs. on An
even grade mesndering round the hillsiaes,
I'll At length they brought ii to their
reservoirs
The V-shaped hume lie particularly suit
able, IL Is easily constructed, when laid
along the side oil hiIl il does not require
support on the lover side. its capacity can
Re readily enlarged by building up the
sides TO the ecaired height
Swan lake IL on the direct route 10
Seattle from the Gam across the Cedar
river. and the grade OF one In I 90 can be
preserved nearly the whole war without
ceviasing far from = straight course. This
lake Is q natural reservoir. rs immense
storage capacity and sstasties makes il
. most valuable factor in Mr.. Williams
scheme.
The tnansl Is SHAPED Ike a isosecies
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