THE CORPORATION OF THE CITY OF PORT COQUITLAM

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6. To get a satisfactory flow through the floodgates
it is obvious that the downstream side should be kept as low as
possible. In other words, the water should flow out to DeBouville
Slough with no restriction. However, to get this unrestricted
flow to DeBouville Slough we need to widen the ditch and add a
second culvert to the crossing at Huber Avenue as recommended in
the initial drainage report.

7. The problem on Boxing Day was not helped by the fact
that our pump was off for several hours due to debris which
jammed the float and caused it to fail ts sense high water.

This appears to’be due to inadequate protection of the floats
from turbulence. We will be correcting this by moving the floats
to anew location and enclosing them with a shroud.

8. There is a problem with the floodgates at the Cedar
Pump Station due to the fact that gravel can get in behind the
hinges and prevent full closure of the gates during times when
water is high on the downstream side. Thus, even if the pump did
have the capacity to draw down the Cedar ditch, it could not lower
it below the level of the water.on the Hyde Creek side because of
backflow through the gates. Our crews will be installing protection
over the hinges to prevent this situation from recurring in the —
future. =

9. Flooding in the Glade Court area is due to the fact
that the storm sewer in this area is discharged by gravity to the
Cedar ditch. When the Cedar ditch is high the storm sewer backs
up through the catchbasins and manholes into the street and also
into private drains wherever the backflow valves are malfunctioning.
Other than keeping the Cedar ditch low, the only cure would be to
install a stormwater pumping station for this outfall.

10. There was flooding towards the east end of Dominion
Avenue even though the ditches at the west end were not over-
flowing. The reason for this appears to be that we did too good
a job of cleaning the major ditch from Laurier to Dominion. Thus
the water which might otherwise have lain on the land between
‘Laurier and Lincoln was able to get to the Dominion Avenue area
quickly.

ll. The Pitt River was high, not only due to high tides
but also due to a record runoff from the Pitt Lake area. This
prevented the floodgates at Dominion Avenue from assisting with
the discharge of the water. The existing pump there was operating
continually but has nowhere near the required capacity.