. Author manuscript; available in PMC: 2023 Oct 1.

Published in final edited form as: Public Works Manag Policy. 2023 Mar 17;28(4):518–536. doi: 10.1177/1087724x231164415

Table 7.

Channel Capacity.

Channel Property	Sunnyside		Rockport		Hoehn		p-Value	Significance^a
Channel Property	m^b	Median	m^b	Median	m^b	Median	p-Value	Significance^a
Longitudinal Slope (%)	20	0.120	19	0.093	18	0.065	6.80E-12	***
Cross-sectional Area, ft²	20	12.22	19	19.63	18	10.20	1.59E-08	***
Channel Capacity^c, ft³ /s	20	0.57/n	19	0.84/n	18	0.35/n	-	-
Capacity to Precipitation ratio (100-year storm)^c	20	0.03*n	19	0.06*n	18	0.03*n	0.029	***
Capacity to Precipitation ratio (10-year storm)^c	20	0.06*n	19	0.11*n	18	0.06*n	0.031	***
Capacity to Precipitation ratio (100-year storm)^c	20	0.11*n	19	0.17*n	18	0.10*n	0.035	***

p < 0.01: ***, p < 0.05: **, p < 0.1 *.

m: Number of ditch sections.

n: Manning’s Roughness Coefficient. All studied channels have similar surfaces (earth, straight, and uniform surface with short grass). Therefore, the channel capacity and capacity-to-precipitation ratio are expressed in terms of n.