In the survival world, we sometimes have a tendency to reinvent the wheel. Rather than focusing on learning the tried-and-true survival methods used by primitive survivalists for centuries, we rely on technology to solve our problems. There's nothing wrong with this per se, since technology has a substantial potential to make our lives easier. Rather than rubbing sticks together, we can now spark a fire with a lighter in seconds. However, it's also reassuring to see much of the survival community focusing on getting back to basics.

Improvised tree water filter 4

A colorized electron microscope image showing green E. coli bacteria trapped on the surface of sapwood. Source: MIT News

One interesting development in this vein came from an unexpected place: Massachusetts Institute of Technology (MIT). This prestigious school has nurtured some of the finest scientific minds of our generation, including numerous Nobel Prize winners. A study performed by a team of MIT researchers has established that the plant xylem found in sapwood can serve as an effective survival water filter, blocking more than 99 percent of E. coli bacteria.

Illustrations from the MIT study. Source: journals.plos.org

If you're not too familiar with plant physiology, the implications of this discovery may be unclear at first. In simple terms, this means that the core of a sap-producing tree branch or twig can be used to filter water and prevent illness. Here's how it works:


We Found Bulk Ammo In Stock:

Disclosure: These links are affiliate links. Caribou Media Group earns a commission from qualifying purchases. Thank you!

  1. Find a pine tree, and cut off a small branch.
  2. Peel away the bark and discard it, so only the inner xylem remains.
  3. Plug or cork a water container with this tree branch water filter, and seal to prevent leaks.
  4. Invert and/or pressurize the container, forcing clean water through the wood, and filtering out bacteria.
Improvised tree water filter 1

A diagram showing the construction of a tree bark water filter. Source: journals.plos.org

According to the study, this simple system can produce up to four liters of clean water per day. The scientists used a plastic tube and hose clamp, then applied 5 psi of pressure to the water vessel to increase flow rate. We imagine this could also be done with a plastic water bottle, some duct tape, and a squeezing motion—just be sure no dirty water seeps around the edges of the wood.

Purpose-built water filters from companies like LifeStraw and Sawyer are great to have in a survival setting, but if you don't have access to these modern conveniences, remember this simple tree branch water filter method.


Prepare Now:

Disclosure: These links are affiliate links. Caribou Media Group earns a commission from qualifying purchases. Thank you!

STAY SAFE: Download a Free copy of the OFFGRID Outbreak Issue

In issue 12, Offgrid Magazine took a hard look at what you should be aware of in the event of a viral outbreak. We're now offering a free digital copy of the OffGrid Outbreak issue when you subscribe to the OffGrid email newsletter. Sign up and get your free digital copy Click to Download!