Lots that drain from rear to front
For lots that drain from rear to front, a swale is located in the back yard where the forward slope of the lot meets the rearward slope of the foundation grading. The rear internal swale directs surface drainage to one, or both, of the side lot swales.
Split drainage lots
For Split Drainage Lots, swales are necessary to convey surface drainage from the highest points to the nearest street or lane.
Common property drainage
Common property swales (Detail A) are possible where common adjacent properties are suitably graded. Grading must provide a minimum of 15 cm of unobstructed width within each property.
If decorative rocks or wood chips are used, the rough grade must be raised to final grade to maintain the function of surface drainage.