Can the Basement Walkout Drain Stand Against Utah Storm?
Hello, everyone. I’m Caleb with Dansie Design Build here in West Jordan, Utah. I’m excited to be here with you today to test out a basement walkout drain against the Utah storms.
Basement Drain Sizes
Should you up your drain size and make it more robust and bulletproof? We already think our drains are bulletproof, but we will show you the math and nerdy details behind it. This way, you’ll see how we’ve come to design our drainage systems and why they work for our area in the desert in Utah.
Estimating Stormwater Going in the Basement Entry
All right, so now we need to get to the math about calculating how much water we can anticipate in this basement walkout entry.
Utah is the second driest state in the country, so we only get a little rainfall. On average, we get 13 inches per year of rainfall. The rainiest month that we’ve had was 2.6 inches of rain in the entire month, and that was in roughly the last two decades. So that’s what we’re calculating off of is 2.6 inches per month.
Let's Do the Math
So we will need to multiply the width of the walkout entry times the length of it. So this one is 4.5 feet wide times 15 feet long, and that’s 67.5 square feet. And so we multiply that by the rainfall we get in a month, which is 2.6 inches. That’s 175.5 cubic feet of rain.
So we will multiply 175.5 cubic feet by 0.623 to convert that to gallons, which gives us 109 gallons of rainfall in that rainy month. We’ll divide that by an assumption of nine rainstorms in that month. That would be every three days, so it’s a good storm.
I’ll divide that by nine — it equals 12.14 gallons of rainwater in a stormy month in Utah. It’s really important to make sure that the drain can handle water without any issues, especially in case of a flood. Now, we can jump into the fun part of testing this walkout drain.
Simulating a Rainstorm for the Test
We’ve got our hose set up to simulate a rainstorm, and we need to figure out how many gallons per minute are coming out of this hose. We’ve got it set to fill up a five-gallon bucket in nine minutes. So if we do nine minutes divided by five gallons, that is 1.8 minutes per gallon. Now, we’ll multiply that 1.8 minutes by 12.14 gallons, and that is 21.85 minutes. In order to withstand a heavy rain, it’s important that the drainage system can handle the same amount of water flow as the garden hose running for this extended period of time.
Running the Simulation
All right, we just hit the 22-minute mark here. We poured this water down the drain and had no problems with flooding. So, this will last and withstand the worst month or one of the worst storms in one of the worst months in the last two decades. So this basement walkout drain is doing great.
At this point, we’re just going to take four five-gallon buckets, dump them straight down, and see how we’re doing with a massive storm like that. That’s 32 gallons of water, handling it just fine. We only calculated that we needed to have 12 gallons go down for a record year with a lot of stormwater, so we’re doing great.
Best Type of Basement Walkout Drain
The type of drain we put in this basement walkout is the type with gravel and a five-gallon bucket in the middle. We put two cubic feet of gravel, then the five-gallon bucket in the middle of that, and this is performing well.
Need Basement Finishing Help?
If you’re still concerned about water, water table rising, or some crazy events happening, we can accommodate that. There are electric pumps that we can use and install. They cost more because of the pump and the associated electrical and plumbing, but those are also an option.
So if you’re looking to remodel your home, build a basement apartment, finish your basement, or build a basement walkout entry with an excellent drain, we can help.
If you also need help designing your basement, drawing plans, or doing everything from idea through planning, city permitting, construction, etc., Visit our website and request a project consultation there. Thank you for your time today, and have a great week.
