## Saturday, November 5, 2022

### Using RDII or RTK or I&I Hydrographs in #INFOSEWER

Using RDII or RTK or I&I Hydrographs in #INFOSEWER – InfoSewer from Innovyze also has the features to model Infiltration/Inflow from Rainfall Events into a Sanitary or Combined Sewershed. There are three parameters, R, T, and K, a Sewershed Area, and a fraction division that divides up the overall R to the individual R's.

Let's consider the following example:

1. The overall R (percent of Rainfall that turns into Rainfall Dependent Infiltration Inflow): 10%
2. R1, R2, and R3 are the individual R's.
3. The fraction division for R1, R2, and R3 is 0.2, 0.4, and 0.4 respectively.

Now, we can calculate the individual R's as follows:

a. R1 = 0.2 * 10 / 100 = 0.02

b. R2 = 0.4 * 10 / 100 = 0.04 c. R3 = 10 - 0.02 - 0.04 = 0.04

So, the individual R's are R1 = 0.02, R2 = 0.04, and R3 = 0.04.

1UH has an overall R (percent of Rainfall that turns into Rainfall Dependent Infiltration Inflow)

a.      R1 = Percent R1 * R / 100

b.      R2 = Percent R2 * R / 100

c.      R3 =  R – R1 – R2

Figure 1 shows the Rainfall for InfoSewer

Figure 2 shows the result of using 100 Percent R1, R2 or R3 at a node

 Figure 1 - Rainfall for RTK in InfoSewer

 Figure 2 - Resultant UH for Nodes with only R1, R2 or R3.