My nonagenarian Grandma lives in Midland, MI. Home of the current floods that are making the news. I didn’t find out about the floods until too late at night to be making phone calls. And I love my Grandma, I would have a really hard time going to sleep if she’s in danger, even if obviously from several hundred miles away there’s nothing I can immediately do.

Time to think like a scientist – time to gather all the data I can, and make a list. Then maybe even without primary data (word from my Grandma, or someone else who has been in contact with her since this started, that she’s okay), I would have enough secondary data that I can go to bed and get an okay night’s sleep.

Why might my Grandma not be okay?

• My grandma jokes regularly about the “Seven Hills of Midland” – aka the 7 highway overpasses. Midland is flat, no rolling hills and protective obvious elevation changes there.
• The article I read talked about two dams collapsing.
• Another article, published late tonight, said there would likely be 9 feet deep of water in downtown Midland in the next 12-15 hours.
• The pictures I could find definitely looked like the water was deep, and like people were caught by surprise (cars left to flood).
• Those last three add up to a LARGE volume of water.
• My parents are known to not pass along bad news in a timely fashion, when there’s nothing the potential recipient could do to change the result.

Why might my Grandma be okay?

• My family is fairly well connected to my Grandma. Likely they would know if there was a problem.
• Coincidentally, I talked to my Mom around 5:30 pm today, and Mom didn’t sound stressed. Not actively reaching out to share news in our family is very different from hiding feelings and news.
• The photos I found were all taken during daylight. Daylight means people are more aware of their surroundings, and there were hours to react before dark.
• My grandma may not talk to people all day every day, but she lives with my aunt who is very social. I doubt somehow her entire social network would manage to avoid any mention of it.
• Due to COVID-19, my aunt is mostly working from home, eg where my grandma is.
• Despite the stereotypes of being a nonagenarian, my wonderful Grandma still has full control of her mental faculties. She’s still sharp at Bridge! She may not be able to outrun a flood, but she can certainly recognize a dangerous situation and use the telephone.
• I pulled up an elevation map. I plugged in Grandma’s address, and got an estimated elevation of ~625 feet. Then I clicked around over the river in the middle of downtown, and bottomed out at about 600 feet. That’s a 25 foot elevation change. Grandma is also about 2 miles away from the closest river. 25 vertical feet and a distance best measured in miles makes for unlikely flood volumes.

Decision?

I can sleep. The elevation difference between the river and my Grandma’s house is substantial compared to the estimated water depth over what’s usually dry land. And she’s about 2 miles from the closest river. And the flood started happening in the middle of daylight, rather than sneaking up on Midland residents in the middle of the night. I’ve emailed my parents, and tomorrow I can make phone calls, to verify my assumptions based on my secondary data.

When you don’t have hard data, the final answer, sometimes it’s enough to go with intermediate data that gives you some level of security that you can infer the answer. But primary data is still always better, and you can bet I’ll be pursuing some about Grandma, first thing in the morning.