Does Miller Park have adequate drainage? A rudimentary lesson in hydrology (or our most interesting post ever)

It's not often I get to use my professional expertise in the environmental sciences to write about sport-related topics, so you can imagine how thrilled I was to hear that the Brewers may be displaced for their upcoming series against the Twins due to severe flooding at Miller Park. As for you Milwaukee-area fans and friends / YCS co-authors who may have flooded basements or--at a minimum--are pissed off at the prospect of the Brewers losing three home games: Sucks to be you. Ha-haw. Etc.

Like any normal person, my first reaction upon reading the story was to check out the USGS website and look up the severity of the storms that caused the flooding. The result: It was a lot of friggin' rain.

The table below shows the Thursday night / Friday mornng rainfall totals and river stage data from the USGS gauge on the Monemonee River in Wauwatosa, about three miles from the stadium. The gauge height in the second column is the water surface elevation relative to a datum of 628.86 above sea level (i.e. a reading of 0.00 = 628.86 above sea level). The rainfall column is the measured rainfall over the given 5-minute interval, and the final three columns are running totals for the time interval given in the column heading.

As the table shows, the rainfall was extremely intense over a two-hour period that resulted in 4.40 inches of rain--just over half of that falling in the first half-hour. In all, from the time the rain began at 11:15 Thursday night through 11:15 Friday night, 5.40 inches of rain fell on 'Tosa.

Without spending the time to look up the rainfall frequency distributions for the Milwaukee area, I'm going to assume that they're only marginally different than those for the northeast Illinois region, which are shown on the following chart pulled from the Illinois State Water Survey, Bulletin 70. The colored lines plot the 30-minute, 1-hour, 2-hour, and 24-hour peak rainfall totals from Thursday / Friday storm that's left the Brewers homeless for the time being.

[For those unfamiliar with the term, a "recurrence interval" is the theoretical period of time that will ellapse between one random event and an event of equal or greater magnitude. For a full explanation, go here.]

By any measure, this was indeed a very rare downpour, and--contrary to popular belief--all that water doesn't just disappear when it hits the ground. If you go back to our table, you see that the Menomonee River crested at 15.35 feet above datum, which, according to NOAA, is expected to occur once every 15 years (roughly) and has been exceeded only three times since 1973. That, my friends, is what we in the biz call a "flood."

Now, none of this answers the question posed in the title. Was Miller Park properly designed to handle severe weather events? Unfortunately, I resold my Standard Design of Stormwater Drainage Systems for 50,000-Seat Baseball Stadiums, 4th Edition textbook for booze money once I got my D in the college course, but I'll guess that a project as costly and conspicuous as Miller Park would have been designed for a 100-year storm and 100-year flood.

If I'm right (probably not the case), it doesn't necessarily signal failure on the part of Miller Park's architects because, after all, it does not sound as though the stadium underwent any permanent damage. Also, my experience has taught me that stormwater management is a highly empirical and highly imperfect art that's very difficult to get "right." (Or at least that's the line I use at work.)

Pretty cool stuff, huh? Well, I hope you've learned something valuable. (Disclosure: You have not.)