Problem

How do I create a storm event using one of the NRCS's six regional rainfall distributions for California (i.e., CA-1, CA-2, CA-3, CA-4, CA-5, CA-6)?

Solution

The NRCS's regional rainfall distributions for California are 24-hour dimensionless rainfall distributions. The process of creating a storm event in PondPack, CivilStorm or SewerGEMS using one of these distributions is similar to creating a storm event using one of the old SCS distributions (Type I, IA, II or III). The difference is that the California distributions are not included with the product installation, so a custom Engineering Library XML file must be added.

A zipped XML file (California.XML) with these distributions is available here. Note that you must be logged in to download.

Once the file is downloaded, unzip it to a convenient location on your machine.

To create the rainfall distribution for your specific location, use the general approach described in this article. However, when you get to the Engineering Library dialog in Step 3, add the California.XML file to your available libraries. You will then be able to select your desired rainfall distribution. Follow the remaining steps as outlined in the article. You can use NOAA Atlas 14 to find the applicable 24-hour cumulative rainfall depth.

See Also

How can I apply a rainfall depth or intensity to a dimensionless curve to create a storm event?

NRCS's Six Regional Rainfall Distributions for California

NOAA Atlas 14