September 2005Urban Planning Carleton University 1 Drainage Systems _____________________________

September 2005Urban Planning Carleton University 2 Storm Drainage Storm drainage -- a replacement of natural system Various components Relationship with street and utilities is maintained Flow is by gravity Major categories: open pit and channels, buried pipes (under streets); drainage tiles (buried around buildings) Streets used for surface drainage as well.

September 2005Urban Planning Carleton University 3 Major Storm System

September 2005Urban Planning Carleton University 4 Storm Drainage: System Components and Design Considerations Street surface Paved & planted areas – min. slope 1% Change in slope by utility holes Utility holes not more than 150m (500ft.) apart Curves (30m radius min.?) Pipes buried min. 1.8m (6ft.)

September 2005Urban Planning Carleton University 5 Storm Drainage: System Components and Design Considerations (Cont.) Min. slope of pipes 0.3% Velocity range in storm drainage system ( m/sec)(2-15ft/sec) to avoid scouring Storm sewers on residential streets – designed for 2-5 yrs (storm) if streets can handle surface flow. Major sewer for 25yrs storm – 100yr storm Dry basements a must

September 2005Urban Planning Carleton University 6 Sanitary Drainage Usually a separate system; kept out of storm drainage system System similar to storm drains but closed -- gravity flow if possible Pollution control (waste treatment & recycling if needed) is essential At the site level pumping avoided if possible.

September 2005Urban Planning Carleton University 7 Sanitary Drainage – cont’d Systems Building Sewer or House Connection Lateral or street sewer Branch or trunk sewer Main or Interceptor Sewer Treatment Plant

September 2005Urban Planning Carleton University 8 Sanitary Drainage: Planning Considerations Normally, planning agencies concerned only with the location and capacity of main sewers and treatment plants, since these must be compatible with density of development. Lateral (street) sewers are to be designed on the assumption of full development of the area. Main sewer design = f(land use & population projections for 25 years or more).

September 2005Urban Planning Carleton University 9 Water Supply Requirements (planning): –Potability –Quantity –Pressure

September 2005Urban Planning Carleton University 10 Water Supply – cont’d Tree-like Pattern Tree Type Pressure drops at ends of long branches - Difficult to keep dead ends clear Loop Network (interconnected) -More than one point of entering supply -Preferred system – avoids drops at end of long brochures Loop type