Cistern Part II

A few weeks back I wrote a post about the rainwater cistern we’re building.  We’ve made a lot of progress since then!  My newest video shows the cistern from dream to (almost) done!

This cistern, made of earthbags like the rest of the house, will be the primary source of water for the house.  We’ll collect rainwater from the roofs of the house and the RV shelter (both of which will be metal).  The water will be used for washing, bathing, and–after running through multiple stages of filtration–drinking.

As you’ll see in the video below, the cistern has various layers on the inside.  We covered the earthbags with papercrete to fill in the grooves and make a smooth surface for the liner to rest against (more about papercrete coming in another post).  Because of the immense weight of the water inside the cistern, we mixed a greater proportion of Portland cement, plus sand, into the papercrete mixture to make it stronger (regular papercrete contains half paper and half Portland cement by weight, and no sand).  To further increase the strength of the papercrete and give it something to stick to, we tied chicken wire to the sides and added more papercrete.

It took several days for the papercrete to dry, and we used fans, heaters and lights in the cistern to help speed up the process since the weather outside was turning cold.

Once the papercrete had dried, Keith lined the bottom with gravel, plastic, an old tarp and styrofoam for protection from moisture and abrasion.  He made the center of the cistern a few inches lower than the sides, and will put the pump there.

He also hung old tarps in the cistern to act as a barrier against the more abrasive papercrete, so that the cistern liner would have yet another layer of protection.

Then it came time to put the cistern liner in.  Keith had this custom made before we had even broken ground, and it was a perfect fit!  Several of us worked together to unfold it and stretch it out around the rim of the cistern while Keith screwed it down.

Then Keith lowered me inside and I stretched the liner out along the floor and against the walls of the cistern.

Lastly, all of us worked together to carry over the enormous wooden lid that Lee had made for the cistern.

We hoisted it onto the rim and then held it up temporarily with stacks of boards while Keith went around the rim with caulking, and then we lowered it into its final place resting place.

A little hatch in the lid provides access into the cistern if we need to go into it in the future to clean it or make repairs.

It’s quite the project, and one of the final things we will have worked on for this season.  The weather is now too cold to work with earthbags or papercrete.  We’ll get back to the project next spring!

Meanwhile, I will upload a few more posts about what we have done on the earthbag house this year.  Enjoy this video showing the cistern from start to (almost) finish!