▁dis charge ▁coefficient , ▁which ▁var ies ▁as ▁follows : ▁ ▁Example : ▁For ▁a ▁sp ill way ▁cr est ▁length / width ▁of ▁ 2 5   ft , ▁Q ▁will ▁vary ▁with ▁H ▁as ▁follows : ▁ ▁For ▁the ▁NR CS ▁comput ations , ▁the ▁mean ▁velocity ▁of ▁approach ▁was ▁assumed ▁to ▁be ▁zero . ▁For ▁the ▁USB R ▁comput ations , ▁it ▁was ▁assumed ▁that ▁linear ▁interpolation ▁could ▁be ▁used ▁to ▁obtain ▁C ▁from ▁H . ▁For ▁a ▁given ▁depth ▁at ▁the ▁sp ill way ▁cr est , ▁the ▁flows ▁calculated ▁using ▁the ▁USB R ▁method ▁are ▁higher ▁than ▁those ▁from ▁the ▁NR CS ▁method ▁because ▁of ▁the ▁higher ▁dis charge ▁coefficients . ▁C ▁increases ▁with ▁H ▁under ▁the ▁USB R ▁method , ▁whereas ▁C ▁is ▁assumed ▁to ▁be ▁constant ▁with ▁respect ▁to ▁H ▁under ▁the ▁NR CS ▁method . ▁ ▁Flow ▁Reg imes ▁ ▁Ch ute ▁Sp ill ways ▁ ▁The ▁flow ▁coming ▁into ▁the ▁sp ill way ▁is ▁sub crit ical . ▁The ▁slope ▁of ▁the ▁ch ute ▁causes ▁the ▁flow ▁velocity ▁to ▁increase . ▁Typ ically , ▁super crit ical ▁flow ▁is ▁maintained ▁in ▁the ▁ch ute . ▁ ▁Ste pped ▁Sp ill way ▁ ▁The ▁flow ▁over ▁a ▁stepped ▁sp ill way ▁is ▁class ified ▁as ▁either ▁n appe ▁flow ▁or ▁sk imming ▁flow . ▁N appe ▁flow ▁reg imes ▁occur ▁for ▁small ▁dis charg es ▁and ▁flat ▁s lop es . ▁If ▁the ▁dis charge ▁is ▁increased ▁or ▁the ▁slope ▁of ▁the ▁channel ▁is ▁increased