| Rainfall Name(s) |
Comments |
Type I 24-hr
Type IA 24-hr
Type II 6-hr
Type II 12-hr
Type II 24-hr
Type III 6-hr
Type III 12-hr
Type III 24-hr |
Original SCS/NRCS distributions
still used
for many projects in the United States. Supplied as polynomial
curves for optimum results over the widest range of Tc values. The 6
and 12 hour durations were added in HydroCAD-9.1 |
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 |
Tabular versions of original
SCS/NRCS distributions. Recommended only for direct TR-20 comparisons.
Available by download only. Right-click any item and save to your
HydroCAD\Rainfall
folder. Latest "version 2" tables from WinTR-55
2.0 are also available here:
Type I
Type IA
Type II
Type III |
| Type II FL 24-hr |
Modified Type II storm used by Southwest
Florida Water Management District and Saint Johns County, Florida. |
| Type IIA CS 24-hr |
Modified Type IIA storm for Colorado
Springs, Colorado. Added in HydroCAD 6.1 |
| Type B 6-hr |
Same as the Emergency Spillway distribution
(ESH), but preset to a duration of 6 hours. Added in
HydroCAD-10 build-4. |
| Type NM 24-hr
|
NRCS New Mexico rainfall
distributions. Added in HydroCAD 10.0
build 20. |
| CA 1-6
|
NRCS Atlas 14 rainfall distributions for
California. (Added in HydroCAD-10.0
build 21) |
HI 1-6
 |
NRCS Atlas 14 distributions for Hawaii, as
published in WinTR-55 v2, and added in HydroCAD 10.2-4b. |
| MSE 1-6
|
Atlas 14 rainfall distributions for midwest
and southeast states developed by NRCS. (MSE
3/4 added in HydroCAD-10.00 build 14, MSE 1/2/5/6 added in
build 21) |
| ND 1/2/3/4
|
Atlas 14 distributions for North Dakota,
developed by NRCS and published in WinTR-55 v2. Originally named
1_ND, 2_ND, etc. Added in HydroCAD 10.2-4b. |
| NOAA A/B/C/D
|
Atlas 14 rainfall distributions for
Mid-Atlantic states developed by NRCS based on NOAA data. (Added in HydroCAD-10.00
build 14 and fully implemented in
the event lookup table in build 21) |
| NOAA10 A/B/C/D
|
Atlas 14 Volume 10 rainfall distributions
for Northeastern states, developed by NRCS and published in WinTR-55 v2 as N10_A, N10_B, etc. Added in HydroCAD 10.2-4b.
Supersedes NRCC distributions (below.) |
| NRCC A/B/C/D
|
Atlas 14 rainfall distributions for
Northeast states developed by NRCS using NRCC data and published in
WinTR-55 as NR_A, NR_B, etc. (Added in HydroCAD-10.00
build 14 and fully implemented in
the event lookup table in build 21) |
| Nevada North/South/West
|
Atlas 14 distributions for
Nevada developed by NRCS and published in WinTR-55 v.1
(Added in HydroCAD-10.00 build 14) |
| Nevada2 North/South/West
|
Updated Atlas 14 distributions for Nevada
developed by NRCS and published in WinTR-55 v2.
(Added in HydroCAD 10.2-4b) |
| SW 1-5
|
Atlas 14 rainfall distributions for
Southwestern states, developed by NRCS and published in WinTR-55 v2. (Added in HydroCAD
10.2-4b) |
| TX A/B/C/D
|
Atlas 14 rainfall distributions for Texas,
developed by NRCS and published in WinTR-55 v2. (Added in HydroCAD
10.2-4b) |
AmSamoa
NoPacific
|
Atlas 14 rainfall distributions for
the Pacific Islands developed by NRCS.
(Added in HydroCAD-10.0
build 21) |
| PR_VI
|
Puerto Rico/Virgin islands 1/6/12/24-hour
1Q/4Q rainfall distributions. (Added in HydroCAD-10.0
build 21) |
| "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 and discussed in the
rainfall.txt file. |
SFWMD 24-hr
SFWMD 72-hr |
Southern Florida Water Management District |
FDOT 1/2/4/8/24-hr
FDOT 3/7/10-day |
Florida Department of Transportation |
Orange County, Florida
6-hour 24-hour |
Use with 10, 25, or 100 year depth.
Added in HydroCAD-10 build-2. |
| SJRWMD 96-hr |
Saint John's River Water (Florida) management District 96-hour
rainfall based on the SCS Type II 24-hour rainfall according to Section 14.2 of
the MSSW Handbook. Provided 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. Added in HydroCAD-10
build-2. |
| Spillway Emergency |
SCS Emergency Spillway Hydrograph (ESH,
a.k.a Type B). |
| Spillway 1-day 10-day |
SCS Principal Spillway Hydrograph (PSH) |
| Constant Intensity |
Usable at any duration. Added in
HydroCAD 7.0. |
Sample A (intensity curve)
Sample B (smoothed curve)
Sample C (mass curve)
Sample D ("Chicago" storm)
Sample E (Incremental rainfall depths)
Sample F (Incremental depths @ uneven times)
Sample G (Cumulative depths @ uneven times) |
Fictional rainfall examples that may be
used as the basis for custom storms. Samples F and
G were added in HydroCAD 10.1 |
| Auckland 24-hr |
Design storms for Auckland, New Zealand,
includes TP108 data and projected future rainfall. Added in HydroCAD 10.1 |
Austin 3-hr
Austin 24-hr, Atlas-14, Zones 1 & 2 |
3-hour Storms for Austin, TX Drainage
Manual 3/8/96 p.2-18
24-hour Storms from Drainage Criteria Manual, Appendix B, 8/7/19, added in
HydroCAD 10.2 |
| TX-TCEQ-PMP
|
Texas Dam Safety Program, TCEQ PMP rainfall
events for durations of 1, 2, 3, 4, 5, 6, 12, 24, 48-72 hours.
(Added in HydroCAD-10.0
build 21) |
| Calgary 24-hr |
Calgary Canada Stormwater Manual, 2000 (includes
event definitions)
Added in HydroCAD-10. |
| Charlotte 6-hr |
2-yr and 10-yr "Balanced Storms" for
Charlotte, NC.
25, 50, and 100-yr storms added in HydroCAD 10
build 11. |
| Charlotte 24-hr |
1-yr storm for Charlotte, NC, added in
build 23. |
| Colorado Springs 2-hr |
Colorado Springs, CO, 2-hour rainfall,
added in build 23 |
Edmonton 4-hr Chicago-style
Edmonton 24-hr Huff-style |
Edmonton Canada Design Standards (includes
event definitions)
2008 Definitions added in HydroCAD 10.0 build 8.
2020 and 2022 Definitions added in HydroCAD 10.2-3a
|
E-WA Short
E-WA Long Region 1-4 |
Eastern Washington State. Added in
HydroCAD 7.1 |
| Fayette-01 (originally Fayette) |
Lexington-Fayette, KY 2001, 5-hr 1995, 6-hr 10/100-yr, 18-hr 1992
Separate "Fayette" files added in HydroCAD 7.0.
Consolidated into single "Fayette-01" file in HydroCAD 10.00 build 21 |
Fayette-05
(Combines Fayette05 and Fayette09) |
Lexington-Fayette, KY 2005, 6-hr 10/100-yr, 24-hr 10/100-yr
Separate "Fayette05" tables implemented in HydroCAD 7.1.
Consolidated into single "Fayette-05" file in HydroCAD 10.00 build 21
and including 1-hr 1/10/100-year storms from Fayettte09 (removed). |
| Fayette-16
|
Lexington-Fayette, KY 2016 - latest
rainfall data
5-hr 1995, 6-hr 10/100-yr, 24-hr 10/25/100-yr, 24-hr 2006
Added in HydroCAD-10.0
build 21 |
| Halifax 24-hr |
Halifax Canada rainfall distributions 2018
24-hr Chicago-style 2/5/10/25/100, Added in HydroCAD 10.1 |
Huff 0-10sm
Huff 10-50sm
Huff 50-400sm |
Illinois Huff distributions from ISWS
Bulletin-71 & Circular-173. Supplied for 1st, 2nd, 3rd, and 4th
quartiles. |
| Huff B70 0-10sm |
Updated Illinois Huff distributions from
ISWS Bulletin-70. Supplied for 1st, 2nd, 3rd, and 4th quartiles.
Added in HydroCAD-10. |
| Huff B75 0-10sm |
Updated Illinois Huff distributions from
ISWS Bulletin-75. Supplied for 1st, 2nd, 3rd, and 4th quartiles.
Added in HydroCAD-10.1-5a. |
| Indy Huff 24-hr |
Variation of the Huff distributions from
Indianapolis Stormwater Manual 5/10/95. |
| Indy Huff |
Indianapolis SQU Guide 7/20/06.
1st, 2nd, 3rd, 4th quartiles. |
| Indy Huff 2011
|
Updated 2011 Indy Huff distributions added
in HydroCAD-10 build 21. |
|
Indy Huff South Bend |
Porter County Indiana, 1st, 2nd, 3rd, 4th quartiles.
Added in HydroCAD-10 build 11. |
| Indy Huff Evansville
|
Huff distributions for Evansville added in HydroCAD-10 build 23. |
| Indy Huff Fort Wayne
|
Huff distributions for Fort
Wayne added in HydroCAD-10 build 21. |
LA County DPW 24-hour
LA County DPW 96-hour |
Los Angeles County DPW 2006 Hydrology
Manual, using 10%+40%+35%+100% depths. Added in HydroCAD-10. |
| NJ DEP 2-hr |
New Jersey DEP Water Quality Storm.
Added in HydroCAD 7.1. Results are identical to latest regulations
using 1-minute interpolation. |
| Ohio PMP 6-hr and 24-hr |
Ohio PMP rainfall distributions (2013
Memo). Added in HydroCAD 10.1
build 2. |
| RSA 24-hr (Type 1, 2, 3, 4) |
"Chicago" style rainfalls for Republic of
South Africa. Added in HydroCAD-10. Rainfall type and depth
maps:
1MB PDF |
| Salt Lake County 3-hour |
10-year and 100-year Farmer-Fletcher
distributions for Salt Lake County Utah.
Added in HydroCAD-10 build 16. |
San Diego 6-hr
San Diego 24-hr |
San Diego Country, CA. Added in
HydroCAD 6.1. |
San Luis Obispo 24-hr
Type U and D
2, 10, 25, 50, and 100 year |
San Luis Obispo, CA, upper and lower
watersheds. Added in HydroCAD-10. |
| Seattle 24-hr |
Seattle, Washington, Flow Control Technical
Requirements Manual, November 2000. |
| SEWRPC
|
SE Wisconsin 90th Percentile storm (added
in HydroCAD-7.0)
SE Wisconsin 2006 storm (added in HydroCAD-10.0 build 14) |
| Shelbyville |
Shelbyville, IN uses standard Huff
distributions, above. |
| St. George 3-hr |
10-yr and 100-yr Farmer-Fletcher
distributions for St George Utah.
Added in HydroCAD 10.1-5a. |
Thurston 24-hr (1/2 to 100-yr)
Thurston 24-hr 1990
Thurston 7-day 100-yr |
Thurston County, Washington. |
Most projects will use one of
the predefined rainfall distributions listed below. The most
common are the