§ 153.096 DRAINAGE.

   (A)   (1)   Sufficient culverts shall be installed to provide for the uninhibited flow of all stormwater, along natural watercourses and at such other locations as necessary to prevent the ponding of water, or the discharge of water over roads.

      (2)   The end area of drainage pipe and waterways shall be computed by use of Talbot’s Formula for drainage areas not in excess of 320 acres.

      (3)   The co-efficient in the formula shall be as follows:

Table III
Drainage Coefficients Drainage - Runoff - 4
Talbot’s Formula - (Approximate Approach)
A = Required Section of Waterway in Square Feet
^ = Drainage Area in Acres            C = Talbot’s Coefficient
Drainage Area		Values of “A”
		Mountainous	Hilly Land		Rolling Land		Flat Land
Acres	Square Miles	C = 1.00	C = 0.80	C = 0.60	C = 0.50	C = 0.40	C = 0.30	C = 0.20
1	0.0016	1.0	0.8	0.6	0.5	0.4	0.3	0.2
2	0.0031	1.7	1.4	1.0	.8	.7	.5	.3
4	0.0062	2.8	2.2	1.7	1.4	1.1	.8	.6
6	0.0094	3.8	3.0	2.3	1.9	1.5	1.1	.8
8	0.0125	4.8	3.8	2.9	2.4	1.9	1.4	1.0
10	0.016	5.6	4.5	3.4	2.8	2.2	1.7	1.2
15	0.023	7.6	6.1	4.6	3.8	3.0	2.3	1.5
20	0.031	9.5	7.6	5.7	4.7	3.8	2.8	1.9
30	0.047	12.8	10.2	7.7	6.4	5.1	3.8	2.6
40	0.062	15.9	12.7	9.5	8	6.4	4.8	3.2
60	0.094	22	17.6	13	11	8.3	6.6	4.4
80	0.125	27	21.6	16	13	10.8	8.1	5.4
100	0.156	32	25.6	19	16	12.8	9.6	6.4
150	0.234	43	34.4	26	21	17.2	12.9	8.6
200	0.312	53	42.4	32	27	21.2	15.9	10.6
250	0.39	63	50	38	31	25	19	13
300	0.47	72	58	43	36	29	22	14
400	0.62	89	71	53	45	36	27	18
500	0.75	106	85	64	53	42	32	21
600	0.94	121	97	73	61	48	36	24
800	1.25	150	120	90	75	60	45	30
1,000	1.56	178	142	107	89	71	53	36
1,500	2.34	241	193	145	121	96	72	48
2,000	3.12	299	239	179	149	120	90	60
2,500	3.91	354	283	212	177	142	106	71
3,000	4.7	405	324	243	203	162	122	81
4,000	6.2	503	402	302	252	202	151	101
5,000	7.8	595	476	357	297	238	179	119
6,000	9.4	682	546	409	341	273	205	136
8,000	12.5	846	677	508	423	338	254	169
10,000	15.6	1,000	800	600	500	400	300	200
25,000	39.1	1,938	1,590	1,193	994	795	596	398
50,000	78	3,344	2,675	2,000	1,672	1,338	1,003	669
100,000	156	5,623	4,498	3,374	2,812	2,249	1,687	1,125
200,000	312	9,457	7,566	5,674	4,728	3,783	2,837	1,891
400,000	625	15,905	12,724	9,543	7,952	6,362	4,772	3,181

 

   (B)   For drainage areas in excess of 320 acres the drainage structure shall be designed in accordance with design standards of the Department of Environmental Protection, and the Commission may request a copy of the permit issued by the Department as proof of compliance.

(Ord. 295, passed 3-14-1974)