How to Build a Gray Water Evaporation Pond & Battery Powered Shower for Burning Man

TL;DR: I built a gray water evaporation pond and battery powered shower for Burning Man. It’s a spin off of the legendary wikiwickatron and has been my must have camp infrastructure since 2016. It’s designed for a camp of ~15 people, but I’ve also doubled the pond size for a food theme camp of ~25 people with a lot of dish water, and had no issues evaporating it all. It also survived raining man 2023 (uncovered), where it evaporated the full pond after a couple days of direct sun and frequent towel dunking. It packs down compact and works ridiculously well. Here's exactly how to build it.

Why the Evap Pond?

Burning Man is leave no trace event, meaning everything you bring in, you pack out, and that includes gray water from cooking, washing dishes, and showering. Dumping gray water on the playa is a big NO and you can even get fined for it. You also can't put it in the portapotties, those are for black water only and can barely handle what they're designed for. If people dumped their grey water in the portos there would be no where to poop. I would rather poop in a porto and evap my shower water than do it the other way around.

So, what do you do with grey water? Your options are basically: contract a removal service (mainly for larger camps), pack it all out in sealed containers (heavy, messy, stanky), or my favorite - evaporate it.

Why the Shower?

I’ve done many burns with just baby wipes, but damn does it feel good to have a proper shower on the playa. With shower comes many grey water, you can build the evap pond on it’s own, but cant bring the shower unless you have a plan for the grey water. It’s a luxury that adds bliss and complexity to your burn.

How the evap pond actually works

The concept is simple and that's why it works so well. This started as the legendary wikiwickatron and has morphed over the years into what it is today. There’s a shallow pond (really just a tarp inside a frame) with a towel rack over it. You drape towels over the rack so the tips hang down into the gray water. The water wicks up the towels throughout the day and evaporates in the desert heat. A couple times a day you take the towels off, fully dunk them in the water, and hang them back up. By the end of the burn you should have a dry evap pond, the towels go in a trash bag, then I clean and reuse them the next year.

The three components

The whole system breaks down into three pieces:

1. Gray water pond — the wood perimeter frame, pond liner, and PVC towel rack
2. Shower platform — a raised wood platform with a walkway so you can stand in the middle of the pond without touching the gray water
3. Shower — a 12V bilge pump in a 27-gallon tote, wired to a light switch and battery clips, pushing water through a hose up to a shower head

You can build all three together or just the evap pond if you don't need the shower. I’ve also doubled the size of the evap pond one year for a camp of ~ 25 people.

How to build it

The full step-by-step with photos, part list, and the hand-drawn wiring diagram is in the Build Guide PDF. I also made a how to Build a Burning Man Shower and Gray Water Evap Pond video. Below is the condensed web version of the instructions:

What you need

Tools

Drill, chop saw, measuring tape, carpenter square, pencil, 3/8” countersink, 11/64" drill bit, 1⅛" circle bit (aka hole saw), wire stripping pliers, dikes/cutting pliers, crescent wrench, pliers, flat head + Phillips screwdrivers, razor blade, lighter, electrical tape, thread seal tape, zip ties.

Parts

I’ll link to as many of the parts as I can at the end of this post, for the complete parts list see the the Build Guide PDF.

Step 1: Pond perimeter & tarp

Start with four 8-ft 2×4s. Cut them in half to 4 feet each, this makes it way easier transport, but feel free to skip this if you’re okay transporting 8’ long 2 x 4s. The heavy tie plates are to join the 4’ pieces back into 8-ft lengths on the playa. That gives you four 8-ft boards.

Lay them out in a square and install one galvanized angle bracket on the inside of each corner with 4 screws per corner. That's your perimeter.

Lay the pond liner over the perimeter and push the corners down to get it as flat as possible. If the liner is bigger than the frame, trim the excess but leave at least 1 foot of overlap on each side. Then pull the tarp back off so it doesn't get damaged while you build the rack.

Step 2: PVC towel rack

Cut 16 pieces of 1" PVC at 23½ inches long each. For each side of the rack, connect 7 of the PVC pieces using 2 tee fittings, 2 ninety-degree elbows, and 1 coupling. That makes one side. Repeat for the other side, then connect both halves together with 1 coupling in the middle.

The perimeter looks square, but it’s actually a rectangle (slightly longer in one direction), and you want to run the PVC rack in the longer direction. The PVC legs go on the outside of the wood perimeter. Position the legs about 2 feet in from the corners and secure each leg with 2 pipe hanger straps screwed into the 2×4.

Step 3: Shower platform

Cut 2 pieces of 2×4 at 2 ft length and 9 pieces of 1×4 at 2 ft length. Pre-drill the 1×4 pieces with an 11/64 bit, then countersink each hole.

Stand the two 2×4s on end. Install 2 of the 1×4 planks on the bottom flush with the ends. Flip it over, install one plank flush with the end on top, then space the rest with about a finger-width gap between each one, that gap lets the water drain through. Install one more plank on the front face, this one holds the PVC pipe for the shower head.

Step 4: Walkway

The shower platform sits in the middle of the pond, so you need a walkway to get out to it. Cut 2 more 2×4s at 2 ft length and 6 pieces of 1×4 at 1 ft length. Same drill/countersink routine. Lay the 2×4s flat this time (not on edge), install the planks with finger-width gaps. The 2×4s slide into the shower platform so it all packs together.

Step 5: Shower head rack

Cut 2 more PVC pieces at 23½" and 2 small pieces at 2". Use 2 pipe hanger straps to mount the PVC vertically in the center of the front of the platform. Connect the two 23½" pieces with a coupling. At the top, install a tee fitting, then use the 2" pieces to add a tee on each side — this creates a little T-shape to hold the shower head and the light switch.

Step 6: Shower electrical

You're wiring a 12V DC bilge pump to a light switch so you can turn the water on and off. Sounds more complicated than it is.

Instead of buying wire on a spool, I cut the ends off an extension cord, it was cheaper and the wire already has a nice outdoor coating. You're working with 16 gauge wire.

Run the hot wire from the bilge pump to the light switch. Run the hot wire from the battery cable clamps to the other terminal on the light switch. Connect the ground wire from the pump directly to the ground wire with the battery cable clamp. Crimp your butt splices and heat-shrink them to make everything waterproof.

The Build Guide PDF has a hand-drawn wiring diagram that makes this way clearer than words can.

Step 7: Shower hose

You need to step down from the ¾" hose (which fits the bilge pump outlet) to ½" (which fits the shower head). Honestly, I had to Frankenstein this together with pieces from the hardware store. There’s likely a better way, but here's the chain:

¾" ID hose → ¾"×½" barb reducing coupling (hose clamped) → ½" ID hose → ½" barb insert female (hose clamped) → ½"×2½" sch 80 nipple (wrapped with thread seal tape) → shower hose → shower head.

The Danco Versaspray is the only shower head I found that works with the pressure from an 800 GPH bilge pump. Standard shower heads (and even low pressure rv shower heads) need way more pressure than this pump puts out.

Step 8: Water tank

Drill a 1⅛" hole in the upper corner of the 27-gallon tote for the hose to pass through. Mount the bilge pump at the bottom of the tote using the M4 bolt with rubber washers on both sides of the tote wall to keep it watertight. Attach the ¾" hose to the pump with a hose clamp.

For the shower head, unscrew it from the hose, thread the hose through the PVC tee fitting on top of the shower head rack, then screw the head back on. That locks it in place.

How to use it on the playa

Setup at camp

1. Build the wood perimeter
2. Lay the tarp over it, push the corners down flat, secure tarp with A-clamps
3. Assemble and attach the PVC towel rack
4. Attach the shower head rack to the shower platform
5. Place the platform in the center of the pond (careful to not puncture the tarp)
6. Place the walkway in the pond
7. Set the water tote outside the pond near the shower head side
8. Run the hose through the tote hole and attach to the pump
9. Zip tie the light switch to the shower head rack
10. Clip the battery cables to a 12V battery
11. Fill the tote halfway with water, that usually lasts a couple showers
12. Drape towels over the PVC rack
13. Wash that crusty booty

Managing the evap pond

Let the towel tips sit in the gray water. The water wicks up and evaporates all day. A couple times a day, pull the towels off, fully soak them in the pond, and re-hang them.

Always filter your dish water through a strainer before dumping it in to the pond, no one wants food scraps rotting in there. Add some vinegar if it starts to smell (a spray bottle works great). And I really shouldn't have to say this but: no pee in the gray water pond.

Showering

Make sure the tote has water before you flip the switch. Do not run the pump dry, it'll burn it out. Get on the platform, flip switch to on, rinse, turn switch off, soap yo body, turn switch on, rinse, turn switch off. Don’t forget, even though you have this nice shower, you still want too conserve water and not overfill the gray water pond. I disconnect the battery after each shower so I don’t kill the battery and the neighborhood doesn’t use it while I’m out.

Tips I've learned over several burns

• Light the perimeter at night. Solar yard lights on each corner. Someone WILL walk right into your pond if you don't.
• Disconnect the battery after each shower so it doesn't drain power.
• Stop showering a day or two before exodus to give the pond time to fully evaporate.
• Bring extra towels and swap them out toward the end of the week. Muddy towels evap slowly.
• Save some empty jugs just in case the evap doesn't fully finish before you need to leave.
• The platform gets slippery when wet, watch your step.
• No shower curtain, on purpose. No curtain means no wind damage, and it makes most people take shorter showers.
• Strain dishwater before it goes into the pond, food scraps can stink.
• Keep the tarp as flat as possible to avoid puddles, shallow water evaps faster
• If worried about rain, bring a tarp to cover the pond.
• If Expecting high winds, lay the towels flat in the pond so the rack doesn’t get damaged.
• I bring 2.5 gallons of water per day, that works for my drinking, shower and cooking water.
• Keep drink a food coolers separate, use the drink cooler water as shower water.
• For warm shower, shower in the evening (waters been heating all day).
• For cold shower, shower in morning (waters been cooling all night).

The whole thing packs down compact

One of the best parts of this design is how small it packs. The 2×4s break down into 4-foot sections, the PVC disassembles, the platform and walkway stack together, and the tote holds all of the smaller parts. Could fit in the trunk of a car if needed.

I've been iterating on this design for several years, if you build it and have ideas for improvements, I'd love to hear them!

See you on the playa.

Part Links

I’ve gathered links for most of the parts, some are affiliate links (no extra cost to you, small kickbacks for me). Most of the tools you may have already so I didn’t get links for all of them. For the complete parts and tool list see the the Build Guide PDF.

Tools

Lumber & brackets

PVC towel rack + shower head rack

Pond liner

Pump + water tank

Plumbing

Electrical

Lighting

As an Amazon Associate, I earn from qualifying purchases at no extra cost to you. I only link to gear I actually use or have tested.