Drainage system calculation

1. Hydrology of Urban Areas
Authors：Raymond Einyu
Prof hab. inż. Paweł Falaciński

2. From Task 2, we get :
Ared=0.0228[ha]=2280[m2
],
q10 (for tm = 10 min, p = 20 %) =3.92 [dm3
/s ha],q15
(for tm = 15 min, p = 20 %) =131.00 [dm3
/s ha],
From materials, we choose Mgr., FGr, CSa, MSa for
kf [m / s] ,which means:
kf(MGr)=9,0 * 10-1
- 5,0 * 10-2
; kf(FGr)=5,0 * 10-2
- 5,0 * 10-3
kf(CSa)=1,5 - 5,0 * 10-3
; kf(MSa)=5,0 * 10-3
- 5,0 * 10-4
For our task:
kf(MGr)=0.3; kf(FGr)=0.01; kf(CSa)=0.05; kf(MSa)=0.001
The depth is 1 m, which mean: ASt = 5 m2
and AN = 4 m2
From task 3,
we got Q10=3.92[dm3
/s] and Q15=2.99[dm3
/s]
1. Absorption trench
1.1. Basic type
（1.1）kf(MGr)=0.3 [m / s]
Ared = 2280[m2
], q10 = 171.89 [dm3
/(s · ha)],
tm = 10 [min], b =1[m], h = 0.4[m],
sk =0.3 ., [-], kf = 0.3 , [m/s].
LR1 = 1.50 [m]
1.2）kf(FGr)=0.01 [m / s]
Ared = 2280[m2
], q10 =171.89 [dm3
/(s · ha)],
tm = 10 [min], b = 1 [m], h = 0.4 [m],
sk = 0.3 [-], kf = 0.01 [m/s]
LR1 = 1.50 [m]

3. （1.3） kf(CSa)=0.05 [m / s]
Ared = 2280 [m2
], q10 = 171.89 [dm3
/(s · ha)],
tm = 10 [min], b = 1 [m], h = 0.4 [m],
sk = 0.3 [-], kf = 0.05 [m/s]
LR1 = 1.50 [m]
（1.4）kf(MSa)=0.001 [m / s]
Ared = 2280[m2
], q10 = 171.89 [dm3
/(s · ha)],
tm = 10 [min], b = 1 [m], h = 0.4 [m],
sk = 0.3 [-], kf =0.001 [m/s].
LR1 = 1.50 [m]
2.1）kf(MGr)=0.3 [m / s]
Ared = 2280[m2
], q15 = 131.00 [dm3
/(s · ha)],
tm = 15 [min], b = 1 [m], h = 0.4 [m],
sk = 0.3 [-], kf = 0.3 [m/s].
LR1 = 0.95 [m]
2.2）kf(FGr)=0.01 [m / s]
Ared = 2280[m2
], q15 = 131.00 [dm3
/(s · ha)],
tm = 15 [min], b = 1 [m], h = 0.4 [m],
sk = 0.3 [-], kf = 0.01 [m/s].
LR1 = 0.95 [m]
2.3）kf(CSa)=0.05 [m / s]
Ared = 2280 [m2
], q15 = 131.00[dm3
/(s · ha)],
tm = 15 [min], b = 1 [m], h = 0.4 [m],
sk = 0.3 [-], kf = 0.05 [m/s].
LR1 = 0.95 [m]
2.4）kf(MSa)=0.001 [m / s]
Ared = 2280 [m2
], q15 = 131.00 [dm3
/(s · ha)],
tm = 15 [min], b = 1 [m], h = 0.4 [m],
sk = 0.3 [-], kf = 0.001 [m/s].
LR1 =0.95 [m]

4. 1.2. With drainage pipe
(sk = 0.3 )
1.1）kf(MGr)=0.3 [m / s]
Ared = 2280 [m2
], q10 = 171.89 [dm3
/(s · ha)],
tm = 10 [min], b =2,0 [m], h = 1,0 [m],
sk = 0.3[-], sg = 0.3 [-], kf =0.3 [m/s].
d = 0.091 [m], D = 0.1 [m].
LR2 = 1.67 [m]
（1.2）kf(FGr)=0.01 [m / s]
Ared = 2280 [m2
], q10 = 171.89[dm3
/(s · ha)],
tm = 10 [min], b = [m], h = 0.4 [m],
sk = 0.3[-], sg = 0.3 [-], kf = 0.01[m/s].
d = 0.091 [m], D = 0.1 [m].
LR2 = 1.67[m]
（1.3） kf(CSa)=0.05 [m / s]
Ared = 2280 [m2
], q10 = 171.89 [dm3
/(s · ha)],
tm = 10 [min], b =5,0 [m], h = 1,0 [m],
sk = 0.3[-], sg = 0.3 [-], kf =0.05 [m/s].
d = 0.091 [m], D = 0.1 [m].
LR2 = 1.67[m]
（1.4）kf(MSa)=0.001 [m / s]
Ared = 2280 [m2
], q10 = 171.89 [dm3
/(s · ha)],
tm = 10 [min], b = 1 [m], h = 0.4 [m],
sk = 0.3[-], sg = 0.3 [-], kf =0.001 [m/s].
d = 0.091 [m], D = 0.1 [m].
LR2 = 1.67[m]
（2.1）kf(MGr)=0.3 [m / s]
Ared = 2280 [m2
], q15 = 131.00 [dm3
/(s · ha)], tm = 15 [min],
b = 2 [m], h = 1 [m], sk = 0.3 [-],
sg = 0.3 [-], kf = 0.3 [m/s].
d = 0.091[m], D = 0.1 [m].
LR2 = 1.02[m]

5. （2.2）kf(FGr)=c [m / s]
Ared = 2280 [m2
], q15 = 131.00 [dm3
/(s · ha)], tm = 15 [min],
b = 5.0 [m], h = 1,0 [m], sk = 0.3 [-],
sg = 0.3 [-], kf = 0.3 [m/s].
d = 0.091[m], D = 0.1 [m].
LR2 = 1.02[m]
（2.3）kf(CSa)=0.05 [m / s]
Ared = 2280 [m2
], q15 =131.00 [dm3
/(s · ha)], tm = 15 [min],
b = 0.1 [m], h = 0.4[m], sk = 0.3 [-],
sg = 0.3 [-], kf = 0.05 [m/s].
d = 0.091[m], D = 0.1 [m].
LR2 = 1.02 [m]
（2.4）kf(MSa)=0.001 [m / s]
Ared = 22800 [m2
], q15 = 131.00 [dm3
/(s · ha)], tm = 15
[min],b = 1 [m], h = 0.4[m], sk = 0.3 [-],
sg = 0.3 [-], kf = 0.001 [m/s].
d = 0.091[m], D = 0.1 [m].
LR2 = 1.02[m]
2. Open retention tank (leakproof)
For this exercise : a= 5 m, b=5 m, h= 5 m
1）
Q10 = 171.89 [m3
/s], tm = 10 [min], a = 5 [m],b =
5 [m], h = 5 [m].
Vrw = Q10 * tm * 60 = 0.00392 * 10 *60 =
2,352
Vrw = 2,353 [m3
] < Vt= m3
].
2）
Q15 = 131.00, [m3
/s], tm = 15 [min], a = 5 [m],
b = 5, [m], h = 5[m].
Vrw = 1,794, [m3
]

6. 3. Infiltrating tank
（1.1）kf(MGr)=0.001[m / s]
Q10 = 171.89 [m3
/s], tm = 10 [min],
Ared = 2280[m2
], q10 = 171.89 [dm3
/(s · ha)],
kf = 0.001,[m/s], ASt = 25 sq.[m2
],
AN = 4 sq. [m2
].
Vrw = 2,352, [m3
] < Vs = 5367 m3
],
ti = 745.6 [h]
（1.2）kf(FGr)=0.01[m / s]
Q10 = 171.89 [m3
/s], tm = 10 [min],
Ared = 2280[m2
], q10 = 171.89[dm3
/(s · ha)],
kf = 0.001,[m/s], ASt = 25 sq[m2
],
AN = 4 sq [m2
]
Vrw = 2,352 [m3
] < Vs =5365 m3
],ti = 745.6
[s]
（1.3） kf(CSa)=0.05[m / s]
Q10 = 171.89 [m3
/s], tm = 10 [min],
Ared = 2280[m2
], q10 = 171.89 [dm3
/(s · ha)],
kf = 0.05,[m/s], ASt = 25sq[m2
],
AN =4 sq [m2
]
Vrw = 2,352[m3
] < Vs = 5365 [m3
],ti =
745.6 [s]
（1.4）kf(MSa)=0.001[m / s]
Q10 = 171.89 [m3
/s], tm = 10 [min],
Ared = 2280[m2
], q10 = 171.89 [dm3
/(s · ha)],
kf = 0.001,[m/s], ASt = 25 sq [m2
],
AN = 4 sq [m2
]
Vrw = 2,352 [m3
] < Vs = 5365 m3
],ti =
1745.6[s]

7. （2.1）kf(MGr)=0.3 [m / s]
Q15 = 131, [m3
/s], tm = 15 [min], Ared = 2280 [m2
],
q15 = 131.00 [dm3
/(s · ha)], kf = 0.3,[m/s],
ASt = 25 sq[m2
], AN = 4, sq[m2
].
Vrw = Q15 *tm*60 = 0.00299 * 15 * 60 =
2,691
Vrw = 2,691 [m3
] < Vs = 4856 [m3
],ti =
674.5 [h]
（2.2）kf(FGr)=0.01[m / s]
Q15 = 131.00 [m3
/s], tm = 15 [min], Ared = 2280 [m2
],
q15 = 131.00 [dm3
/(s · ha)], kf = 0.01,[m/s],
ASt = 25 sq [m2
], AN = 4 sq [m2
].
Vrw = 2,691 [m3
] < Vs = 4856 [m3
],ti =
674.5 [h]
（2.3）kf(CSa)=0.05 [m / s]
Q15 = 0.00299 [m3
/s], tm = 15 [min], Ared = 2280 [m2
],
q15 = 131.00 [dm3
/(s · ha)], kf =0.05,[m/s],
ASt = 25 sq. [m2
], AN = 4 sq. [m2
].
Vrw = 2,691 [m3
] < Vs = 4856 [m3
],ti =
674.5 [h]
（2.4）kf(MSa)=0.001 [m / s]
Q15 = 131.00 [m3
/s], tm = 15 [min], Ared = 2280 [m2
],
q15 = 131.00 [dm3
/(s ·ha)], kf = 0.001,[m/s],
ASt = 25 sq [m2
], AN = 4 sq. , [m2
].
Vrw = 2,691[m3
] < Vs =. 4856 m3
],ti =
674.5 [h]
4. Storm box (sg=0.95[-])
（1.1）kf(Mgr.)=0.01[m / s]
Ared = 2280 [m2
], q10 = 131.00 m3
/(s · ha)],tm
= 10 [min], b = 0.8 [m], h = 1,0 [m],
sg = 0.95 [-], kf =
0.001[m/s].LRs = 1.54 [m]

8. 1.2kf( FGr)=0.01[m / s]
Ared = 2280 [m2
], q10 = 131.00 dm3
/(s · ha)],
tm = 10 [min], b = 0.8 [m], h = 1,0 [m],
sg = 0.95 [-], kf = 0.001,
[m/s].LRs = 2.02 [m]
（1.3） kf(CSa)=0.05[m / s]
Ared = 2280 [m2
], q10 = 0.00392m3
/(s · ha)],
tm = 10 [min], b = 0.8 [m], h = 1,0 [m],
sg = 0.95 [-], kf = 0.001,
[m/s].LRs = 1.63 [m]
2.1）kf(MGr)=0.3 [m / s]
Ared = 2280 [m2
], q15 = 131.00 m3
/(s · ha)],tm
= 15 [min], b = 0.8 [m], h = 1,0 [m],
sg = 0.95 [-], kf = 0.001,
[m/s].LRs = 1.69 [m]
2.2）kf(FGr)=0.01 [m / s]
Ared = 2280 [m2
], q15 = 131.00 m3
/(s · ha)],tm
= 15 [min], b = 0.8[m], h = 1,0 [m],
sg = 0.95 [-], kf = 0.001,
[m/s].LRs = 2.25[m]
（2.3）kf(CSa)=0.05 [m / s]
Ared = 2280 [m2
], q15 = 131.00 m3
/(s · ha)],
tm = 15 [min], b = 0.8 [m], h = 1,0 [m],
sg = 0.95 [-], kf = 0.001, [m/s].
LRs = 1.83 [m]