CEA 2.3.11 Practice #2

Select the Rational Method Formula.

For Alvin, TX, what is the rainfall intensity for a 100 -yr, 1 hour rainfall? Use the Precipitation Frequency Data Server site and write it down in your notebook. https://hdsc.nws.noaa.gov/hdsc/pfds/index.html

A developer purchased a five-acre farm in Alvin, TX. As part of the project, a 35,000-sq-ft asphalt parking lot area will be placed on one side of the five-acre farm, with a 100-yr, 1-hr rainfall intensity. What is the runoff coefficient adjustment factor? Write it down in your notebook.

A developer purchased a five-acre farm in Alvin, TX. As part of the project, a 35,000-sq-ft asphalt parking lot area will be placed on one side of the five-acre farm, with a 100-yr, 1-hr rainfall intensity. What is the runoff coefficient? Write it down in your notebook.

A developer purchased a five-acre farm in Alvin, TX. As part of the project, a 35,000-sq-ft asphalt parking lot area will be placed on one side of the five-acre farm, with a 100-yr, 1-hr rainfall intensity. What is the area of the farm?

A developer purchased a five-acre farm in Alvin, TX. As part of the project, a 35,000-sq-ft asphalt parking lot area will be placed on one side of the five-acre farm. Use the rational formula to calculate the Pre-Development. Write it down in your notebook.

A developer purchased a five-acre farm in Alvin, TX. As part of the project, a 35,000-sq-ft asphalt parking lot area will be placed on one side of the five-acre farm. What is the area of the parking lot? Write it down in your notebook, label it A1.

Now subtract the area of the parking lot from the area of the farm land. Write it down in your notebook and label it A2.

What is the runoff coefficient for the asphalt parking lot? Write it down in your notebook.

Calculate the composite runoff coefficient for the farmland and parking lot. ((Cc = Cfarm*A2)+(Casphalt*A1))/(A1+A2) Write it down in your notebook.

Calculate the Post Development Stormwater Runoff. Write it down in your notebook.

Calculate the change in peak runoff (difference in post development and pre development)