A-18.1, r. 7 - Regulation respecting standards of forest management for forests in the domain of the State

Schedule Disposition versions

2012-09-01

SCHEDULE 5

Culvert size

The table below indicates, in the case of a control at the intake, the diameter of the culvert to be installed based on the peak flow calculated (Q10 or Q1.20) and the type of intake. The culvert diameters indicated in this table are designed to prevent the calculated peak flow from exceeding 85% of the vertical clearance of the pipe after burial to a depth equivalent to 10% of its clearance.

Diameter required for corrugated metal or thermoplastic round pipes according to the peak flow and the type of intake.

Type of pipe	Q10 or Q1.20
Class of flow (m3/s)		Required culvert 
diameter (mm)
	Type of intake*		
	Projection	Bevelled or straight	
Round	0	-	0.11		0	-	0.12	450
	0.12	-	0.14	0..13	-	0.16	500
	0.15	-	0.23	0.17	-	0.25	600
	0.24	-	0.33	0.26	-	0.37	700
	0.34	-	0.46	0.38	-	0.51	800
	0.47	-	0.64	0.52	-	0.70	900
	0.65	-	0.81	0.71	-	0.90	1,000
	0.82	-	1.28	0.91	-	1.41	1,200
	1.29	-	1.88	1.42	-	2.08	1,400
	1.89	-	2.24	2.09	-	2.47	1,500
	2.25	-	2.63	2.48	-	2.90	1,600
	2.64	-	3.53	2.91	-	3.90	1,800
	3.54	-	4.59	3.91	-	5.07	2,000
	4.60	-	5.83	5.08	-	6.44	2,200
	5.84	-	7.24	6.45	-	8.00	2,400
	7.25	-	9.72	8.01	-	10.74	2,700
	9.73	-	12.65	10.75	-	13.98		3,000
	12.66	-	16.05	13.99	-	17.74	3,300
	16.06	-	19.95	17.75	-	22.05	3,600
Structural plate	16.80	-	20.94	18.57	-	23.13	3,670
	20.95	-	25.80	23.14	-	28.51	3,990
	25.81	-	31.11	28.52	-	34.38	4,300
	31.12	-	37.02	34.39	-	40.92	4,610
	37.03	-	43.56	40.93	-	48.15	4,920
	43.57	-	50.75	48.16	-	56.09	5,230
	50.76	-	58.60	56.10	-	64.78	5,540
	58.61	-	67.15	64.79	-	74.25	5,850
	67.16	-	76.40	74.26	-	84.45	6,160
	76.41	-	86.40	84.46	-	95.50	6,470
	86.41	-	96.03	95.51	-	107.33	6,780

Example

Q10 = 3.5 m3/s Culvert required: 1,800 mm;

Projecting intake Burial: 180 mm.

If the height of the bank makes it impossible to install a 1,800 mm pipe, the flow must be distributed equally between 2 or more pipes. For 2 pipes, the flow must be divided by 2: 3.5 m3/s ÷2 = 1.75 m3/s. Then the diameter corresponding to that flow must be determined. In the present example: 1,400 mm. Therefore, 2 pipes 1,400 mm in diameter must be installed, instead of a single 1,800 mm pipe. Each 1,400 mm pipe must be buried 140 mm deep. The same procedure applies where the calculated peak flow (Q10 or Q1.20) corresponds to a culvert whose diameter should be greater than 3,600 mm, except if the installer uses one or more structural plate culverts having a diameter greater than 3,600 mm.

O.C. 498-96, Sch. 5.