Taken from another site.

 

 

Fenders by province, collected 12 October 2007

BC - Motor Vehicle Act, MOTOR VEHICLE ACT REGULATIONS
Mudguards
7.06 Every motor vehicle, trailer and semitrailer not constructed so that the spray and splash of water and mud to the rear of the vehicle is minimized shall be equipped with mudguards and, if necessary, mudflaps.

Alberta - ALBERTA REGULATION 322/2002 ,Traffic Safety Act, VEHICLE EQUIPMENT REGULATION
Mudguards.
64 The body of a motor vehicle or trailer or a fender, mudguard or similar structure must cover the width of the tire and extend to the mid‑point of the axle when viewed from behind the vehicle.

Saskatchewan -T-18.1 - Traffic Safety Act - V-2.1 REG 10 VEHICLE EQUIPMENT, 1987
Fenders or mudflaps
52(1) Subject to subsections (2) and (3), the vehicle shall have, for each tire, a fender, mudflap or body overhang that:
(a) reduces the rearward projection of gravel, mud, water and snow from the tire;
(b) is located so that the lowest point of the fender, mudflap or body overhang is above the ground a distance that is not greater than two thirds of the horizontal distance from that point to the centre of the wheel; and
(c) extends across the full width of the tire.
(2) The requirements of subsection (1) apply to wheels on steering axles only when the wheels are in the straight ahead position.
(3) Subsection (1) does not apply to a modified vintage vehicle when the vehicle is being operated on a dry, paved surface.

Manitoba –Highway Traffic Act
SPLASHGUARDS OR FENDERS
Splashguards required
48 Every motor vehicle and every trailer, except a farm trailer, shall, when upon a highway, be equipped with splashguards or fenders adequate to reduce effectively the wheel spray or splash of water from the roadway to the rear thereof, unless adequate protection is afforded by the body of the motor vehicle or trailer or by a trailer drawn by the motor vehicle; and the splashguard shall comply with the standards prescribed therefor under the regulations.

Ontario - Highway Traffic Act R.S.O. 1990, CHAPTER H.8
Mudguards
(3) Every motor vehicle and every trailer shall be equipped with mudguards or fenders or other device adequate to reduce effectively the wheel spray or splash of water from the roadway to the rear thereof, unless adequate protection is afforded by the body of the motor vehicle or trailer or by a trailer drawn by the motor vehicle. R.S.O. 1990, c. H.8, s. 66 (3).
Exception
(4) Subsection (3) does not apply to motor vehicles or trailers in an unfinished condition while proceeding to a works for completion. R.S.O. 1990, c. H.8, s. 66 (4).

Quebec
I was unable to locate appropriate resources

New Brunswick - CHAPTER M-17 Motor Vehicle Act
The act contains no references to Fenders or Mud Guards

Nova Scotia - Motor Vehicle Act CHAPTER 293 OF THE REVISED STATUTES, 1989
Dropping contents of vehicle and mudguards
199 (2) Every motor vehicle and every trailer shall be equipped with mudguards, fenders or flaps adequate to reduce effectively the wheel spray or splash of water from the roadway to the rear of the vehicle or trailer, unless the spray or splash is effectively reduced by the body of the vehicle or trailer or by a trailer drawn by the vehicle.

PEI – Highway Traffic Act
http://www.gov.pe.ca/law/statutes/pdf/h-05.pdf
Can only find a reference saying it’s “unlawful to splash pedestrians or others”

Newfoundland and Labrador - CONSOLIDATED NEWFOUNDLAND REGULATION 1007/96 Licensing and Equipment Regulations under the Highway Traffic Act (O.C. 96‑211)
Other equipment

32. (7) A motor vehicle and a trailer shall be equipped with mudguards or fenders adequate to reduce effectively the wheel spray or splash of water from the roadway to the rear of the vehicle or trailer, unless adequate protection is afforded by the body of the motor vehicle or trailer or by a trailer drawn by the motor vehicle.