Curve Numbers in the NRCS Rainfall-Runoff Method - CE 433 - Class 23 (6 Mar 2020)

[@ChaymaeIbrahimi]

Very clear thank you. In case someone is wondering what do we mean by "Impervious area". It means the number of square feet of hard surfaced areas which either prevent or retard the entry of water into soil mantle, as it entered under natural conditions as undisturbed property, and/or causes water to run off the surface in greater quantities or at an increased rate of flow from that present under natural conditions as undisturbed property, including, but not limited to, roofs, roof extensions, patios, porches, driveway, sidewalks, pavement and athletic courts.

[@IsaacWait]

Great description -- thank you!

[@jilliandakharjana5758]

May I please know the name of the book that you referred to for the estimation of Curve Number? The one that has the tables describing land use description and hydrological soil groups. Thanks.

[@matthewchurly7785]

Just google TR-55 urban hydrology for small watersheds. It is a publically available document.

[@jilliandakharjana5758]

@@matthewchurly7785 thank you. Appreciate it.

[@joejr.3874]

So let’s say I am only improving 30% of my land. How do I find out the volume of runoff? Do I multiple my runoff (in inches) by the area I’m improving? Or the entire area of the land???

[@ndaolivier2011]

Very good explanations....Thank you

[@moo_moon128]

wow. I keep running away from maths but math keeps chasing me . No matter what field I choose. hehe. Thank you for posting this.

[@IsaacWait]

Haha, yeah -- you can never escape math!