Gutter Flow Equation

Where q gutter flow rate n manning s coefficient s x roadway.

Gutter flow equation.

Suffix 1 represents the base condition to be scaled and suffix 2 the scaled result. N manning s coefficient. An inch of rain is not much but it if falls in half an hour it could flood a gutter. S x roadway cross slope.

Wsdot assumes 0 016 velocity of gutter flow ft sec ratio of frontal flow to total gutter flow hec 22 equation 4 16. Qw q qs 0 157 0 085 0 072 m 3 s note. The amount of collected water increases until it spills over the sides of the gutter. The total rainfall and how rapidly it falls will affect the runoff from the roof.

Solving for flow width. If gutters don t slope water gathers in them. Increase the pitch of the gutter. Step 5 calculate the gutter flow in width w using equation 11 5.

S longitudinal slope. Gutter and inlet equations anchor. Solving for gutter flow rate. Manning s coefficient n roadway cross slope s x longitudinal slope s.

Curb type gutter equations formulas design calculator. The spread is usually referred to as ponded width t as shown in figure 10 10. The best and simplest is the critical depth equation. Figure 11 3 can also be used to calculate the flow in a composite gutter section.

Critical depth occurs near the outfall of every box gutter. The ponded width is a geometric function of the depth of the water y in the curb and gutter section. Top width of flow prism. The standard is about inch per 10 feet.

For box gutter depth any equation incorporating flow depth and width will do. The above recommendations assume that you have properly sized downspouts every 40 feet. Curb gutter flow rate. If gutters slope too severely they don t hold water and water could splash over the sides in heavy rain.

As with gutters a downspout s capacity must match or. A depressing depth. Here we can calculate for curb gutter flow rate. The usual nomenclature applies q flow w width y depth.

Inches hec22 table 4 3 manning s n for street and pavement gutters. Total roof area also affects runoff. T flow width. Curb type gutter equations formulas design calculator.

D flow depth at curb. Increasing the pitch increases a gutter s handling capacity but the gutter may look askew over a long run. Martin wanielista robert kersten and ron eaglin. Storm drainage systems 11 9 9 january 2001 conndot drainage manual 11 9 5 v type gutter sections procedures figure 11 1 can also be used to solve.

Ft hec 22 equation 4 2 depth of flow at face of curb. Curb type gutter calculator solving for flow rate given roadway cross slope. Math geometry physics force fluid mechanics finance loan calculator.