Tag Archive for: Lipschitz

Parallel Between Flooding and Corona Virus

A friend, Dr. Matthew Berg, CEO and Principal Scientist of Simfero Consultants, observed that flooding and the corona virus are alike. The more I thought about that, the more intrigued I became. Controlling both requires similar strategies.

Controlling Convergence is Key

Of course, when looking at the corona virus, it spreads from “one-to-many.” And when looking at flooding, the relationship is reversed, “many-to-one.” But stay with me for a moment. Because similarities will become apparent at the point of convergence.

Dozens of creeks and streams flow into Lake Houston from approximately 2,600 square miles.

Creeks and streams from 2,600 square miles converge on Lake Houston during heavy rains. That can cause flooding. Likewise, thousands of corona virus victims could soon flood the area’s limited number of hospitals.

Harvard Study Shows Hospitals Rapidly Becoming Overwhelmed

Last week, ProPublic published an article, “Are Hospitals Near Me Ready for Coronavirus? Here Are Nine Different Scenarios.” The article is about a Harvard Global Health Institute study. It modeled different rates for the spread of the virus: 20%, 40% and 60% of the population infected over 6, 12 and 18 months. The authors then compared results against the number of available hospital beds in various areas.

Interestingly, they used the Houston region as their first test case. In only one of the nine scenarios, did we have enough hospital beds to handle the flood of corona victims. That scenario was for 20% infected (the smallest percentage) over 18 months (the longest period).

Darkest blue represents 6-month peak, middle blue a 12-month peak, and lightest an 18-month peak.

In the graph above, the areas shaded with crosshatching represent the normal baseline level of bed occupancy for non-corona patients in Houston hospitals. The colored areas represent the percentage of the area’s population projected to seek admission within a 6-, 12- or 18-month period.

2.8X Available Hospital Beds

The ProPublica article about the Harvard study goes into much more detail. It looks at all 50 states, the number of ICU beds, available ventilators, people etc.

In Houston, the researchers found, “The influx of patients would require 14,300 beds over 12 months, which is 2.8 times the available beds in that time period. The Harvard researchers’ scenarios assume that each coronavirus patient will require 12 days of hospital care on average, based on data from China.”

ProPublica Article on Harvard Study

One hospital administrator said, ““The reality is that you can’t create unlimited hospital beds and ventilators. We have what we have, so we really have to hope that it’s enough, and that we’re prepared enough.”

Flattening the Curve Prevents Avoidable Deaths

Said the authors, “By modeling the data over the three time periods, the scenarios illustrate how much the nation could “flatten the curve” with social measures to ensure hospitals have greater capacity to care for coronavirus patients.”

Epidemiologist Dr. Marc Lipsitch, head of the Harvard T.H. Chan School of Public Health’s Center for Communicable Disease Dynamics said, “The way to permanently stop new cases from setting off long chains of transmission is to have each case infect considerably less than one case on average. The numbers will go down. There will still be little outbreaks, but not big ones.”

Basically, Dr. Lipsitch argues that controlling the flood of victims early at the source is the only way to avoid overwhelming health care resources.

This YouTube video from Vox about Avoidable Deaths shows how slowing things down and flattening the curve helps everyone.


Parallel With Physical Flooding

It’s much the same in physical flooding. Too much water in too little time overwhelms the available capacity of streams, rivers and lakes. Property is destroyed. People die.

That’s why flood experts argue for upstream detention. This post about closing the detention pond loophole in Montgomery County flood regulations contains two FEMA case studies from Texas about the value of detention ponds. Slowing water down prevented flooding.

The beat the peak loophole in MoCo regulations says that if developers can prove they can get their runoff to the river before the peak of a flood, they don’t have to build detention ponds. That’s what happened in the 2200-acre Artavia development. Of course, this incentivizes developers to get their water to the river ASAP.

And that’s exactly the opposite of what you need to protect lives and property downstream.

It’s kind of like saying, “Let’s infect everybody as fast as we can.”

Slowing down the spread of the virus will give researchers time to develop a vaccine or for the population to develop herd immunitybefore hospitals become overwhelmed.

Unfortunately, there is no vaccine or herd immunity to protect downstream residents from greed. And there never will be. That’s why we need to close the “beat the peak” loophole before it’s too late.

Posted by Bob Rehak on 3/25/2020

939 Days after Hurricane Harvey

The thoughts expressed in this post represent opinions on matters of public concern and safety. They are protected by the First Amendment of the US Constitution and the Anti-SLAPP Statute of the Great State of Texas.