223 



TORONTO HARBOUR— ITS FORMATION AND PRESERVATION. 



[1854 



ITS PHESERVATION. 



Having by sufficient evidence set forth the probability if not 

 the certainty of an early destruction of the harbour by the dam- 

 ming up of its entrance, we may now proceed to the practical, and, 

 so far as the commercial interests of Toronto are concerned, the 

 vitally important part of the inquiry, and endeavour to obtain a 

 satisfactory answer to the query — How can such a catastrophe be 

 obviated or indefinitely postponed ? A problem which becomes 

 of comparative easy solution when the immediate cause of the 

 evil is set beyond a doubt, and the nature of its operations clearly 

 ascertained. 



To keep those harbour channels subject to obstruction from 

 moving sand-bars in a navigable condition, three expedients are 

 generally resorted to : First, continuous or periodical dredging ; 

 second, the application of a scour to remove the bar as it is formed ; 

 third, the construction of such works as are calculated to prevent 

 the deposition of the sand in the channels, by retaining it at a 

 distance, when its source is known, or by diverting it to those 

 points where depth of water is not essentially necessary.. 



The first is often applied as a temporary remedy, and as such 

 may at times be viewed as a fit expedient, but to employ it as the 

 lasting counteracter of a constantly increasing evil, is to adopt an 

 indubitable source of unceasing attentiou and endless outlay ; it 

 should accordingly be dreaded as a permanent restorative, and 

 employed only by compulsion from unusual difficulty in the ap- 

 plication of other measures that are generally less costly and always 

 more satisfactoiy. 



The second is obtained at marine ports by taking advantage of 

 the tidal fluctuations, and is generally produced twice each day 

 by using the currents of rivers at low tide, or by holding up the 

 sea water in large artificial basins at flood, then concentrating and 

 guiding, it to the bar at ebb. The impracticability of procuring 

 a scour on Lake Ontario from tidal fluctuations must be admitted, 

 since practically there are none ; true it is we have a gradual rise 

 and fall of about two feet annually, and at times successive oscil- 

 lations in level to the extent of several inches, much resembling 

 small tidal waves; but the latter, although they give to the surface 

 water at the entrance of the harbour a perceptible current, are too 

 rare and too feeble to be of any real value. Nor have we at 

 Toronto a river sufficient for the service, for the Don has hitherto 

 failed to keep open its own channel to a greater depth than two 

 or three feet. Indeed I feel quite convinced that all attempts on 

 these inland waters to keep permanently open those harbour 

 channels much exposed to beach drifts by other than the largest 

 class of rivers must sooner or later prove ineffectual. The currents 

 of the Nottawasaga, of the Sable, and of the Saugeen, are unable 

 to keep open to a sufficient depth or width the mouths of those 

 rivers, and yet they are in volume from ten to twenty times 

 greater than the Don. 



The third remedy can always be advantageously employed in 

 cases when the obstructions are the natural results of moving 

 beaches, and when the works are located and executed with proper 

 care they usually answer a good purpose ; the second is often after 

 great outlay under favourable circumstances of doubtful efficacy. 

 In the case of Toronto, even if we had at command a current 

 capable of removing the sand on its arrival at the point of the 

 shoal, I question very much if it should be considered as more 

 than an auxiliary, since it woidd of necessity tend to spread 

 the deposit, and thus, although injuring the channel in a less 

 degree, would impair the harbour generally by lessening in depth 

 the approach to it. Without doubt the steps likely to confer the 

 greatest security, and hence the most advisable to be taken, are 



those which are calculated to keep the drift at a distance from that 

 point where it is not wanted. 



I therefore beg leave to submit for your consideration the fol- 

 lowing preventive and remedial measures : — 



1st. That a Groyne should be constructed at the Light-house 

 point from the shore outward to 8 or 9 feet water for the reten- 

 tion of the moving sand, on the principle of those very sinrple 

 natural ones shown by Figs. 6, 7, and 8. 



2nd. That an auxiliary Groyne be run westerly across the outer 

 edge of the shallows, a little to the south of Gibraltar point. 



3rd. That a Pier or breakwater be built along the south side of 

 the channel as shown on Fig. 21, increasing the navigable water 

 to six hundred feet, by cutting off the point of the shoal north of 

 the proposed line of pier. 



The third alone would probably suffice for many years to keep 

 the channel perfectly free from deposit; but the sand, if not re- 

 tained at the Light-house point, would as at present be moved 

 northward by the southerly waves, and would gradually accumu- 

 late to such an extent as to fill up the whole space along the south 

 side of the pier until ultimately rounding its extremities. To 

 effectually prevent this the first and second should also be con- 

 structed, the first would divert the drift westerly into deep water, 

 where the navigation could never practically be obstructed ; and 

 the second groyne placed about midway between the first and 

 third would have the effect of counteracting all progressive action 

 alonsr the west end of the Peuinsula. 



If the destruction of the Harbour entrance, and the formation 

 of the Peninsula generally, be satisfactorily determined, I think 

 it is equally conclusive that these works, or works of the same 

 character, would, if established in due time, be exercised to a very 

 beneficial result, — the preservation of the Harbour for an indefi- 

 nitely long period. 



There are other evils, which, if they affect the salubrity of the city 

 more immediately than they prove detrimental to the Harbour, 

 are not on that account of the less consequence. The Don annu- 

 ally transports even at this day considerable quantities of silt from 

 the interior of the country to the Marsh, and, during freshets, a 

 portion escapes from thence into the harbour through the open- 

 ings in the beach between the Wind-mill and Privat's, tending 

 of ctfurse, when deposited in the basin, to lessen its depth. All 

 the drains and sewers empty into the bay r making it, in truth, the 

 grand cess-pool for a population of probably 30,000 inhabitants, 

 with their horses and cattle. The sewers of necessity bring down 

 no inconsiderable portion of solid matter, impairing greatly the 

 purity of the water in the Harbour, as well as gradually lessening 

 its depth. This evil, increasing in a proportionate ratio to the 

 growth of the city, might be greatly ameliorated, if not almost 

 totally removed, by the construction of a main sewer along the 

 whole city front eastward to the Marsh. Into this sewer all the 

 lateral ones from the north, and the drainage of gas, chemical, and 

 other such like works, should be made to discharge. The feculent 

 mixtures produced would thus be collected and conveyed to a 

 distant point, where, by similar operations to those now ripening 

 in Britain, which will strip them not only of their noxious, but 

 even of their offensive characters, might be profitably converted 

 into a marketable commodity of the highest value to the farmer. 



The prejudicial effect of the Don on the depth of the Harbour 

 may also be destroyed by closing its present outlet, and forming 

 an opening of sufficient capacity in the beach separating the main 

 Lake from Ashbridge's Bay. 



All proposed works relative to the improvement of the harbour 



