Question $3)$ SCS Hydrograph $(10$ pts$)$

Problem Statement: Your engineering company has been selected to design the bridge

improvements for a site in Fairfax County. You need to calculate the design hydrograph for the

site based on the SCS CN unit hydrograph method.

Develop a unit hydrograph for the watershed for a $1$ hour duration storm

Apply the Unit Hydrograph that you developed for the design storm provided

Your GIS department has provided you with:

Table $1$: Land use and soil spatial information

Average slope $=2\mathrm{.}5\%$

Length to divide: $4\mathrm{.}2$ miles

Assume: $B=1\mathrm{.}67Tr$

Table $2$: Design hyetograph $($Effective Precipitation$)$

Justify your assumptions, if any.