Here's a summarized table for Section 3.10.3 "Unit Hydrograph Method" from the SWMM User's Manual

 Here's a summarized table for Section 3.10.3 "Unit Hydrograph Method" from the SWMM User's Manual:

Aspect	Details
Method Overview	The Unit Hydrograph Method approximates runoff response to rainfall using a unit hydrograph, which represents the time distribution of runoff from a unit of rainfall.
Key Parameters	- Ttot: Total duration<br>- Tgage: Time at the rain gauge<br>- Tdry: Time since the last rainfall<br>- IA: Initial abstraction<br>- P: Precipitation
Process	- Involves calculating RDII (Rainfall Dependent Infiltration and Inflow)<br>- RDII flows computed for each wet time step<br>- Precipitation records and RDII convolution processed at the rain gauge recording interval
Parameter Estimates	- Requires R-T-K parameters for each unit hydrograph<br>- Derived from site-specific flow monitoring data<br>- Continuous flow monitoring program needed for accurate estimates<br>- Additional initial abstraction parameters (Ia0, Iamax, Iar) may also be required
Numerical Example	- Illustrates the construction of an RDII interface file for a hydraulic simulation<br>- Uses rainfall time series data from a single rain gauge<br>- Example involves a node named N1 servicing a 10-acre area<br>- Example uses a set of 3 unit hydrographs (UH1, UH2, UH3)
Practical Application	- The method is used to model how stormwater runoff in urban areas responds to rainfall events<br>- Particularly useful in planning and managing urban sewer systems to handle rainfall-induced flows<br>- Can be customized to specific urban areas based on local rainfall data and sewer system characteristics

The Unit Hydrograph Method in SWMM is a powerful tool for urban stormwater management, offering a detailed approach to simulating how rainfall impacts urban runoff and sewer systems. 🌧️💧🏙️📊👷🏻‍♀️📈🌍🛠️