Provincial Board of Health Annual Report 1906, pg. 21
By John Galt, C.E. & M.E., Consulting Engineer
The Mayor and Council, Fort William : —
Gentlemen: —
Combined System. — I have now studied the problem of drainage for Fort William and find that a complete system can be designed and constructed to carry- off all surface, cellar and house drainage by natural gravitation to the Kaministiqua and Neebing Rivers.
Present Sewers. — In working out this problem, I found it absolutely necessary to disregard largely the attempts which had been made some years ago by the construction of your present system.
Low Land. — The northeast part of the town is the only section which presents more than the ordinary difficulties. Here the case is a very special one and requires special means for its satisfactory solution.
The general elevation of the ground to the north of Victoria and easterly along Simpson St., including the district east of the main line of the C.P.R., is rather too low to be of much value and importance unless raised to a suitable height to permit of proper cellar drainage.
The ground elevation falls to the north and east towards the river outlets where it is only about a couple of feet more or less above the lake level.
I find that this area should have a falling gradient from the natural elevation on Victoria St., to about five feet above lake level at the banks of both rivers. By establishing this, complete natural drainage and sanitary conditions can be secured by special means, which will gradually but ultimately make it a most valuable district.
This, of course, means time and money to gradually raise the present natural grade from one foot to about three feet in some places. This would correspond closely to the elevation of the rail level on the main line of the C.P.R.
Numerous Outlets. — The draining of this area of all surface and cellar water, including house waste, by natural fall to both rivers, will require numerous outfalls of special design and construction laid to flat gradients, running from each district to the Kaministiqua or Neebing River, as the case may be.
Special Design of Drain. — The area served by each outlet main is, of course, small owing to the fact that the lateral branches can only extend a very limited distance and in many cases these will have also to be built of special design and cross section so that they will equally suit the minimum dry weather flow as well as storm water, which the ordinary circular sewer pipe could not do under the circumstances.
In addition to all this, special provision will have to be made for cleansing, flushing, ventilating, etc.
The cross section to be employed, while somewhat similar to the egg-shaped sewer, will be much better, being simpler and cheaper in construction and much more efficient in service because it will not be arched over, but built up of concrete from a plain flat bottom with almost vertical sides, and tapering straight inside from a small radius of invert to a large expanding width at top and height to suit this combined service.
This style of channel which will form the various outlets, mains and principal tributaries, will be deeper than usual and large enough to secure the maximum velocity and discharge with the least fall. The top of these outlets will always be well above the hydraulic gradient along its entire length, including its entry into the river, which will give a free discharge and prevent them from being sewers of deposit as far as possible.
The top of this specially designed sewer will be covered over with flat plain concrete slabs six feet long, more or less, strong enough to carry the superincumbent weight of dead and live loads on roadways, although in some cases some slight metallic reinforcing may be found necessary on the larger sizes. The bottom, including the invert and the two sides, will be built up in one continuous piece of a plain and strong design to give a good foundation and resist tendency to collapse.
House Connections. — The connections from cellars and houses, including street grilles, can be easily made and will enter about high water mark.
The accompanying plan illustrates fully this new style of sewer, which I have designed to meet some of the difficulties of your drainage problem, more especially in the low lying northeastern areas, and so avoid a costly pumping system which in any event would be only utilized for cellar and house sewage.
Manholes. — Provision will be made at manholes for ventilation, cleaning and flushing, and the system generally made quite handy for inspection and handling. Am also relying upon the liberal use of water carriage and frequent flushing, after an abundant supply is obtained from Loch Lomond.
Drainage District. — The accompanying plan shows very closely the boundaries of the various districts drained by their respective and separate outlets, twelve of these for the present being located and numbered to correspond accordingly with the outlets.
Low Level District. — The Districts Nos. 5, 6 and 7, with outlets to the Kaministiqua River, and Nos. 10, 11 and 12, with outlets to the Neebing River, in all about 400 acres, are the specially low flat areas requiring special care and design in order to secure natural fall for the free discharge of surface and cellar drainage.
These outlets must be brought in from both rivers on very flat gradients by means of specially constructed channels, from which main tributaries will run, and lateral branches for short distances only.
To enable this to be done properly, it will be absolutely necessary to have the general grade raised on an average about two feet, some portions requiring three feet and others only one foot.
Districts 5, 6 and 7. — District No. 5 of about 50 acres, can best be drained by outlet across from Dease St., while No. 6 and 7 can be drained from McTavish and Bain Streets.
Districts 10, 11 and 12. — The outlet No. 10 on May St. can easily take drainage from property on both sides as far up as Cumming St., and No. 11 on Prince Arthur Boulevard can be designed to drain a considerable portion to the east, while No. 12 outlet channel from the Neebing, along Simpson St., with branch mains, can be utilized for that section.
Business and Central District No. 4- — No. 4 outlet and district which is the central and most business section adjacent to Victoria and Simpson Sts., should be re-arranged and made to. discharge via Stewart St., so that good fall can be got on Victoria St., from Archibald or John St., and also on Simpson St., from Bethune. The area of this important district is not large and my investigation leads me to think that until this Victoria St. sewer is revised and reconstructed, good results will never be obtained.
Apart from the irregular and defective grades, the main along a portion of Victoria St. seems larger than is required for storm water, and, being of circular form, makes it unsuitable and unsanitary for minimum dry weather flow.
District No. 8. — District No. 8 is, of course, now under construction and can be made to drain from Arthur St. to the Neebing River.
District No. 3. — District No. 3 can be nicely drained by outlet to the Kaministiqua from Ridgeway, and so can No. 2 by outlet either on Duncan or Garnet Streets.
Large District No. 1. — The large District No. 1 to the west as shown on plan, can all be drained by one outlet to the Kaministiqua from Christana, or it could be divided in two by the construction of an intercepting main on Tarbutt St., or Ford St., with outlet to the Kaministiqua River, but in view of drainage on West Fort being demanded sooner, then Pump House could probably be abandoned. I think the best and cheapest plan is to discharge as shown.
The territory to the north of this No. .1 District can all be effectively drained to the Neebing River.
Drainage Areas. — The drainage areas are as follows: —
| No. | 1 | 800 | Acres |
| 2 | 200 | ||
| 3 | 120 | ||
| 4 | 85 | ||
| 5 | 55 | ||
| 6 | 40 | ||
| 7 | 40 | ||
| 8 | 105 | ||
| 9 | 80 | ||
| 10 | 75 | ||
| 11 | 75 | ||
| 12 | 130 | ||
| Total | 1,805 | Acres |
Difficulties of Design and Construction.— The problem of drainage, especially in the low lying districts, is after all not an impossible task, but it will have to be done with the utmost care and skill, not alone because of the engineering difficulties, but because of the difficulties likely to be encountered during construction in a wet and treacherous soil.
Sewer Piping. — I do not think that ordinary vitrified clay sewer pipe should be used above twelve inches in the low districts and above eighteen inches in No. 1 district, and if ever used at all the thickness and strength must be much greater than was the case in the twenty-four inch main which was laid on Miles St., and afterwards collapsed.
The design of manholes and street catch water basins will have to be very different from those in use.
It may be advisable in after years to modify these outlet channels and construct them similar to a septic tank, so that nothing but clear liquid would empty into the rivers.
I hope I have succeeded in explaining to you in a simple and practical way the more important features of this drainage problem, and on hearing from you at any time, shall be only too pleased to prepare the necessary profiles and working details, etc., for purposes of construction and the establishing of permanent street grades.
Yours respectfully,
John Galt,
Consulting Engineer.