The Seattle post-intelligencer. [volume] (Seattle, Wash. Terr. [Wash.]) 1888-1914, 1892-02-04

| feet long through Union bay comnletes the CON
| neeuon with deep water in Lake Washington.
IN ADDITION the smith cove project requires
dam at the nsrrows of Salmon bay which shall
| serve to raise its level to the required heigbt
Inc estimated cost of the shishole bay sys-
YEN, Win masonry locks, is s2,900,0oO, and OF
the smith cove route sS,5oO0Oo
Inc shllshole bay system costs 100000 less
/ tnSn that by smith core On the other hand,
the latter route possesses advantages in that it's
entrance Is IN the harbor of Seattle whereas the
entrance TO the other is five and oue-haIf miles
instant, aud. secondly. the smith cove entrance
anu iock are less exposed TO bonbardnnent by
| an enemy fleet For these reasons the Smith
cove route Is TO be preferred
ny either OF these routes there VIII be added
| 70 the commercial facilities of Seattle three
| Iresh water areas where timber wharves can be
| constructed and cheapiy maintained, and where
| vessels can lie in perfectly quiet water of con-
| slant level
| In the Sound at Seattle the tide has an aver
| age range of more than eleven feet and an ex-
IRENE range OF nearly eighteen feet These os-
| ciiatlons OF level are all embarrassing to COM
| nerce, and wooden wharves are liable to be des-
tFoseu oy the teredo in a few mouths Marine
insects are very destructive 10 piling and other
timber placed in the waters of Puget sound.
salmon bay, maintained at the level of Lake
Union, VIII contain thirty five acres of water
area more than twenty-five feet deep, and an sd-
dltlonal area of los acres can be brought to the
| same depth by moderate amount of dredging
Lake Union has an area OF i99 acers of depth
/ OF twenty-five feet, which can if desirable, be
increased by dredging. The total area of the
| lake is 905 acres
These two areas combined about equal the
| total area of the docks of London, and they can
| readily be made equal to the area of the Liver
/ pool docks
Lake Washington contains an ares of $50
| square miles, about $500 acres, of which
about 22,0oo are covered with greater depth of
| water than twenty-five feet
IA ali essential respects the extension from
Lake Washington to Lake Samamish CON
| forms to the dimensions of the canal and locks
below, connecting Lakes Washington and Union
| with Puget sound
IN nxlng upon the dimensions of the canal
and locks. the board has endeavored to provide
accommodations for the present and
Immediately prospective demands on
commerce, and TO so leave the matter
that, II IN the future greater accommodations
should be required, they can be added without
interfering with the usefulness of tie present
works. The locks are designed to pass the
largest type OF ships which visit Puget sound
ihere are two classes of vessels which cannot
be passed through the proposed lock. ..ocean
greyhounds, similar 10 those plying on the
Atlantic, which would be declared on account
OF their great length, and the large first-elass
pattle ships and protected cruisers of the navy
which would be debarred on account OF their
great breadth of beam. To these may be added
| the large side-wheel steamers engaged in local
traflc on Puget sound of the type of the Olym-
plan, which is 70 feet wide, guard to guard
III future developments shall show the de-
STABILITY OF providing for the passage of such
shipping, other locks can be built of size sufli-
cIent to afford the required accommodation.
The ideal arrangement for this canal would be
that laid down for the Manchester ship canal,
where three locks are planned side by side, one
oox6OO, one 50x3o0 and one 30xl75
Water Supply.
Lake Washington furnishes ample water sup
ply for the service of the canal
As 1t is probable that the lower lock will be
used much more frequently than the upper
lock- and as the latter at each lockage passes less
water than the former, it is necessary TO provide
for the passage from Lake Washington to Lake
Union OF the additional amount of water re-
quired for the lower lock Proper weirs for this
purpose provided at the upper or portage
lock 1T future developments should show the
necessity Tor more water than can well be taken
from Lake Washington an addition supply can
be obtained by turning the water of Cedar river
into the lake. This can be done at compare
lively small expense
Notifications.
Various notifications of the plan finally fixed
upon were considered by the board of engineers.
Principal among these was the project of
bringing Lakes Union and Washington to- the
same level, and avoiding thereby the lock at the
portage.
Three ways of doing this are available: By
lowering Lake Washington to the level of Lake
Union; by raising Lake Union TO the level of
Lake Washington, or by establishing a common
intermediate level by raising one and lowering
the other.
Upon full consideration of the advantages
and disadvantages which these notifications
presented II was concluded that, owing to the
disturbance they would make in values along
the shores of the lakes, and TO the consequent
damages, the best plan would be TO leave the
lakes at their present levels aud connect them
by lock.
Another modification consisted in putting in
the outer lock at the head of salmon bay and
dredging thence a channel through Salmon aud
shilshole bays TO the deep waters OF the Sound;
but this would largely increase the excavation
required, and the project would be deprived OF
the great benefit OF the fresh water basin al
salmon bay. This is modification which
might we'll be considered, however, il the ques-
tion of damages at Ballard and elsewhere along
Salmon bay cannot be satisfactorily solved.
If, in the Smith cove route, the question OF
damages arising from raising and maintaining
permanently the waters OF Salmon bay at the
level of Lake Union be not capable of satisfac
tory adjustment, the lower part of that bay,
where the greater amount of damages would ac-
crue, be left in its present condition and the
excavation can be carried through from the
outer lock to the Fremont cut ana Lake Union,
and be separated from the lower part of Salmon
bay, in its passage through the head OF that
bay, by embankment
A modification was also considered of substi-
tuting for masonry locks, locks composed partly
OF masonry and partly of timber II this were
done there would be a saving OF $4,000 in the
cost OF the outer lock, whether situated at
smith cove or shilshoe bay, and a saving of
s25S0n0 in the cost of the lock at the portage be-
tween Lakes Union and Washington
In the project for the erection of a canal con
Meeting Lakes Washington aud Samamish ii is
designed 10 carry the level OF Lake Samamish
through the canal to lock placed near Lake
Washington to overcome the difference of ten
and hall feet and 10 make the canal partly in
cut and partly in embankmenL This project
would have TO provide for the drainage of Lake
Samamish through the canal. The valley of
the samamish river is occupied by the Seattle,
Lake shore 4 Eastern railway, aud contains
2lS1 acres OF valuable land. the surface of
which is below the level of Lake -amamish. To
drain the valley independent low water chan
nes would have to be provided,
By placing dam near the lock at the outlet
Of the valley ana dispensing with the indepent-
ent drainage channels, the low lands Ia the
valley would be flooded
The disturbance Of values and resultant dam
ages due to the flooding OF the valley. would
largely exceed the cost of draining by the
independent channels
As the building of this section OF canal has
not been seriously contemplated, the time and
care applied TO making the plans and estimates
Tor il have not been as great as TO the other
portions from the SOUND to Lake Washington.
The project of the board contemplate the
-aTer, hay fft rFsa al