Standard Rainfall Tables
The following standard rainfall tables are provided with HydroCAD. Any
storms added since the last HydroCAD release can be downloaded from this page.
(Right-click the link and save to your HydroCAD\Rainfall folder).
Most projects will use one of the standard SCS/NRCS rainfalls listed near the bottom of the page. If you need a rainfall that is not listed here, you may be able to create a custom rainfall table.
(Unless otherwise noted, each rainfall is included with all versions of HydroCAD starting with 6.0.)
Austin 3-hr (2, 5, 10, 25, 50, & 100 year events for
Austin, Texas)
Charlotte 6-hr (2 & 10 year "Balanced Rainfall" events for
Charlotte, NC)
Chicago Storm: This term refers to a technique for using IDF coefficients to define a mass curve. This is illustrated in the "Sample D" rainfall table (installed with HydroCAD-8 and later) and discussed in the rainfall.txt file. (This format is also used to define the South African rainfall tables, listed below.)
Constant Intensity (Usable at any duration - Added in HydroCAD 7.0)
Eastern Washington State (Added in HydroCAD 7.1)
Short Duration; Long Duration:
Region 1,
Region 2,
Region 3,
Region 4
Fayette 5-hr 1995 (Lexington-Fayette, KY,
added in HydroCAD 7.0)
Fayette 6-hr 10-yr
Fayette 6-hr 100-yr
Fayette 18-hr 1992
Fayette05
6-hr 10-yr (Lexington-Fayette, KY - revised 2005
rainfalls, added in HydroCAD 7.1)
Fayette05
6-hr 100-yr
Fayette05 24-hr
10-yr
Fayette05 24-hr
100-yr
Fayette09
1-hr 1-yr (Lexington-Fayette, KY - new 2009
rainfalls, added in HydroCAD 9.2)
Fayette09
1-hr 10-yr
Fayette09 1-hr
100-yr
FDOT 1, 2, 4, 8, & 24-hour (Florida DOT)
FDOT 3, 7, & 10-day
Huff 0-10sm (1,2,3,4th quartiles) (IL Huff distributions: ISWS Bulletin-71 &
Circular-173)
Huff 10-50sm (1,2,3,4th quartiles)
Huff 50-400sm (1,2,3,4th quartiles)
Huff B70 0-10sm 1Q (IL Huff distributions:
ISWS Bulletin-70, Download only)
Huff B70 0-10sm 2Q
Huff B70 0-10sm 3Q
Huff B70 0-10sm 4Q
Indy Huff 24-hr (Indianapolis Stormwater Manual 5/10/95)
Indy Huff
1st Quartile
2nd Quartile
3rd Quartile
4th Quartile
(Indianapolis SQU Guide 7/20/06)
LA County, California: 24-hour 96-hour (using 10%+40%+35%+100% depths) Download only
NJ DEP 2-hr (New Jersey DEP Water Quality Storm, Added in HydroCAD 7.1)
Orange County, Florida: 6-hour 24-hour (Download only. Use with 10, 25, or 100 year depth)
San
Diego (6 & 24-hr) (San Diego Country, CA,
Added in HydroCAD 6.1)
Seattle 24-hr
Shelbyville, IN (Uses standard Huff distributions, above)
SEWRPC-90 (SE Wisconsin 90th Percentile storm, Added in
HydroCAD-7.0)
SFWMD (24 & 72-hr) (Southern Florida Water Management District)
SJRWMD (Saint John's River Water management District) 96-hour rainfall based on the SCS Type II 24-hour rainfall according to Section 14.2 of the MSSW Handbook. Available in half hour increments as described in MSSW, or tenth hour increments for greater accuracy and consistency with the Type II storm on which it is based: half-hour tenth-hour
South Africa 24-hr rainfalls (download only):
Tabular rainfalls: Type 1,
Type 2,
Type 3,
Type 4
(for any HydroCAD version)
Coefficient rainfalls:
Type 1,
Type 2,
Type 3,
Type 4
(requires HydroCAD-8 or later)
Rainfall type and depth maps:
1MB PDF
Spillway Emergency (SCS Emergency Spillway Hydrograph - ESH.
Also used as Type II 6-hr storm)
Spillway 1-day 10-day (SCS Principal Spillway Hydrograph - PSH)
Thurston 24-hr (0.5, 2, 10, 25, 50, 100-yr) (Thurston County, WA)
Thurston 24-hr 1990
Thurston 7-day 100-yr
Standard SCS/NRCS rainfall
distributions:
(These are coefficient-based rainfalls for optimum results over
the widest range of Tc values)
Type I 24-hr
Type IA 24-hr
Type II 24-hr 12-hr
6-hr
(12-hr and 6-hr added in HydroCAD 9.1)
Type III 24-hr 12-hr
6-hr
(12-hr and 6-hr added in HydroCAD 9.1)
Tabular versions of SCS/NRCS rainfalls
(Recommended only for direct TR-20 comparisons - download only)
Type I 24-hr Tabular
Type IA 24-hr
Tabular
Type II 6-hr
Tabular
Type II 12-hr Tabular
Type II 24-hr
Tabular
Type II 48-hr
Tabular
Type III 24-hr
Tabular
Local versions of the SCS/NRCS rainfalls:
Type II FL 24-hr (Florida Modified)
Type IIA CS 24-hr (Colorado Springs Modified, Added in HydroCAD
6.1)
If you need a rainfall that is not listed here, you may be able to create a custom rainfall table.