Channel Lining Calculator

Design channel linings using permissible velocity or tractive force methods. Evaluate grass, riprap, concrete, and other lining adequacy for erosion protection.

Lining Property Guidance

Lining Type	n	V_max (fps)	tau_max (psf)
Bare Soil	0.025	2	0.02
Grass	Varies	4	Varies
Riprap	Varies	14	Varies
Gabion	Varies	15	Varies
Concrete	0.015	20	10

Grass Retardance Classes (HEC-15)

Class	Height	Condition
A	36 inches	SCS retardance class A
B	24 inches	SCS retardance class B
C	8 inches	SCS retardance class C
D	4 inches	SCS retardance class D
E	1.6 inches	SCS retardance class E

Input Parameters

Design Configuration

Design Method

Lining Type

Vegetation Height

Maintained stem height used by HEC-15 Eq. 4.1

Vegetation Condition

Growth Form

Underlying Soil

Channel Geometry

Bottom Width

Initial Trial Depth

Starting estimate; HEC-15 normal depth is solved from design discharge

Side Slope (z)

:1 (H:V)

Horizontal to vertical ratio

Channel Slope

ft/ft

Flow & Site Conditions

Design Discharge

cfs

Bend Shear Factor

Kb = 1.0 for straight channels

Required Safety Factor

HEC-15 default is 1.0; use 1.0-1.5 where added conservatism is warranted

Include side slope shear analysis

Ready to Calculate

Select lining type and enter channel parameters to check adequacy.

For educational purposes only. Not a substitute for professional engineering judgment.