Hydrologic Soil Groups may be considered as rainfall-runoff models. So, only one thing that you have to do is to calculate infiltration rate in your each soil.

For example:

Soils Hydrologic Group C is when relative runoff potential is high, and infiltration rate (in/hr) is 0.05-0.15.

You should use this information in whole city in sites where you have measured the infiltration (soil absorbs rainfall), or you get this kind of data from other resources.

For more information on using most limiting of hydraulically transmissive horizon/layer in the soil, see the publication or the guid below:

https://web.ics.purdue.edu/~vmerwade/education/cngrid.pdf

http://www.bwsr.state.mn.us/outreach/eLINK/Guidance/HSG_guidance.pdf

This should help in USA. NRCS TR-55 has the soil series by hydrologic group

https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1044171.pdf#page104

see Appendix A-1

Some states have updated STREAMSTATS by USGS to include CN and percent of drainage areas in the various hydrologic soil groups, calculates urban areas, etc., and flood frequency estimates. Check out streamstats.gov to see if updated for your area. Basically you select a location on a stream or river, it will calculate drainage size, flood frequency estimates using USGS equations that apply to your location, state, physiographic area, etc. In SC, it estimates percentage in each soil group, estimate of urban imperveous surfaces, forest, etc. It is also important to recognize the confidence limits of estimates as level of uncertainty.