Run-off from tall/ residential development
Run-off from tall/ residential development
(OP)
I am trying to find some guidance with regard to calculating surface water run off from a collection of mult storey buildings. Building regs give guidance on roof pitch but not in relation to the catchment created by the building elevation.
Any guidance would be appreciated.
Many thanks
Any guidance would be appreciated.
Many thanks





RE: Run-off from tall/ residential development
RE: Run-off from tall/ residential development
RE: Run-off from tall/ residential development
Try restating your question and providing more detail. Answers given by others seem to assume too many of these unknowns.
good luck
RE: Run-off from tall/ residential development
Ae=0.5 Sq.root (Aa.Sqaured + Ab.squared-2Aa-Ab.cos.theta)
Aa and Ab being the area of the vertical walls.
I can't find any refrence or guidance in this respect.
Many thanks for your assistance
RE: Run-off from tall/ residential development
I see no relevance of building elevation with respect to total runnoff.
If it rains straight down, your footprint area is the roof area.
If you had rain blowing sideways or...lets say 45 degrees...the roof gets the same...
...and one side of the building gets some rain that reaches the street and is collected by normal street drainage.
...which is offset by the otherside which blocks rain getting to the street.
I'd say "it all comes out in the wash"...it is over complication to consider the building height with respect to storm runoff.
RE: Run-off from tall/ residential development
However, put a tall building in the way and it will certainly intercept a volume of rainfall based on the angle of rainfall and height of building.
Downstream I can see it all evening out, but those drains immediately adjacent to the buildings, I can see where they could be impacted. Depending on how tall, prevailing winds, and how many other buildings are situated around it, it might be inconsequential or it might be something you should reasonably consider.
And I think it's one more reason I'll just stay out in the country..
RE: Run-off from tall/ residential development
This can easily be accounted for in the C factor - bump it up by a few percent or just add a safety factor to your design.
RE: Run-off from tall/ residential development
RE: Run-off from tall/ residential development
Kind Regards
johnny
RE: Run-off from tall/ residential development