TL;DR There was a big pipe over the entrance to the cave at the bottom of Blue Hole. Now there’s a great grate.

The Great Grate Installation Project History

A quick disclaimer: I’m writing this blog post from memory, so some of the dates may not be entirely accurate. If I find better dates, I’ll update the post.

Blue Hole is an Artesian Well that gets 3000 gallons per minute of water flow from a small cave system. Until 1972, it was used by the federal government as a fish hatchery. When the federal government stopped using the land, it was turned over to the City of Santa Rosa in 1973.

Because of its high flow, the water is exceptionally clear, and the Blue Hole became a popular spot for scuba diving.

In 1976, two open water divers from a student group at the University of Oklahoma entered the cave system that begins at (today’s depth) about 87 feet. Presumably, they became disoriented and perished in the cave system.  The New Mexico State Police Dive Team recovered their bodies. Afterward, the City closed the entrance to the cave.

The cave remained sealed until 2013 when a team from The ADM Exploration Foundation conducted a preliminary assessment of the cave.

Before 2013, there was a grate covering the cave, but in 2013, that grate was replaced with “The Snorkel.” The Snorkel was a 3.5-foot wide piece of steel pipe that was placed over the entrance to the cave to block the entrance.

In 2016, when ADM returned to conduct their exploration of the cave system, a grate was added between the cave entrance and the snorkel. There were some unintended consequences of adding the grate to the entrance. Divers could no longer see into the cave. In addition, the grate started to accumulate gunk (that’s the technical term) that was restricting the flow of water from the cave. As a result, a crack began to develop, widening the entrance to the cave.

In 2018, several people, including me, from Deep Blue Scuba in Albuquerque began an attempt to remove the grate to improve the flow of water and stop the erosion. In 2018 or 2019, the grate was successfully removed; however, the erosion continued.

By 2022, a combination of erosion and people digging at the cave entrance had widened the opening to the cave to a point where the cave was accessible to divers. I had been documenting the erosion/damage for several years. In discussions with the City of Santa Rosa, it was decided that the time had come to remove the snorkel.

The Plan

In late 2022, I sat down with several officials from the city, and we formed an initial plan. I wanted to bring in a group of volunteers. The city considered paying us, but I nixed that in the first meeting. My thinking was that local dive businesses directly benefit from the availability and goodwill of Santa Rosa, so the least we could do was give a little back. However, Santa Rosa graciously paid for some equipment we needed for the project (e.g., lift bags), hotel rooms, and meals for the team, which we all appreciated.

I made an initial dive in late 2022 to get some measurements for the grate, and then went back with Gabe Pulu, the owner of Scuba 8 in Albuquerque, to confirm measurements. Gabe and I did most of the planning on the dive side of things, and we recruited the team that would be involved. 

The Team

From left to right, Rudy Martinez (Viking Dives), John Fowlds (Divin’ Dawg Scuba), Bill Tydeman (Viking Dives), Gabe Pulu (Scuba 8), Mike Zumstein (Scuba 8), Byron PIatt (Scuba 8), Andrew Foote (Scuba Sasquatch), LeAnn Conlon (not pictured, Scuba 8), and Andrea Madrid-Martinez (not pictured, Viking Dives).

The photo’s a little washed out, but we did manage to get a picture of the whole team. Leann is on the left, and Andrea is on the right.

Operation Goodbye Snorkel

On April 15, 2024, the team arrived and conducted a dive brief. The basic plan was to connect The Snorkel to the crane, pull it out, and then replace it with a grate. We also planned to drop in a basket to move out some of the heavier items (rocks, etc.) that were near the entrance to the cave.

Day 1 consisted of pulling out The Snorkel and clearing the mouth of the cave. Most of the clearing work was done by feel, in zero visibility conditions. This was very physical work, where we moved hundreds of pounds of junk with lift bags and brute force.

The initial dive to yank the snorkel required everyone present. We had people rigging the snorkel for removal, and others working as safety divers or relaying messages to the crane driver.

The debris removal was done in teams of two. One team was in the water nearly all day, while the other teams had surface intervals.

We ended day 1 by dropping in the new cover as close to the entrance as possible.

The snorkel looks a little different at the surface. The new grate is on the left of the photo.

On Day 2, I went back in first to survey the state of things with better visibility. Once I’d made that assessment, we developed a plan of attack for moving the new cover to the entrance.

The whole team dived for the move. We attached multiple lift bags and moved the grate near the cave opening. By that time, the visibility was so bad that we ended the dive. 

Once the viz improved, Gabe and I made a second dive where we moved the new cover into the spot where it is resting now.

I’d been diving sidemount all weekend, and everyone had been diving nitrox. On this dive, I had my nitrox tanks topped off with air, so I was diving Nitrox 23. Gabe was on 32%, and didn’t hit his NDL, but I exceeded mine.

I’d figured that I might end up in deco and had pre-planned that as a contingency. I had worked really hard on that dive, shoving the grate around, so I took a long time doing deco. I’d racked up about 20 minutes of hang time, but I wanted to be very conservative given how hard I’d worked so I extended my hang times quite a bit. I hung out at 10 feet until I had a surfGF of about 50.

Team in the water.

There’s a little more work to do, but this video accurately represents what things look like today.

A note about the people that played a role from the City of Santa Rosa:

I can’t say enough good things about the folks who work for the city. I’m going to butcher titles here, and I hope I don’t leave anyone out. If I do, I apologize in advance – I should have taken better notes! 

Mark, the park manager, has been nothing but fantastic to work with since he started working with the city. He’s not a diver, but he tries to make Blue Hole better for divers at every turn.

Adrian, Runner, and Joe were the guys who “made it happen.” They got the materials for the new cover, rented the crane, built the cover, and generally provided a lot of good input on the design for the cover.

Shelly, the Director of Public Safety, handled all the legal aspects of our operation and was great to work with too.

Finally, Santa Rosa’s Mayor, Nelson Kotar, was extremely supportive. If you’ve spent any time at Blue Hole, you’ve probably met Nelson. He’s always looking for opportunities to make Santa Rosa better, and he has been great.

I’m pleased to have been a part of the team that worked to improve the Blue Hole for everyone’s enjoyment. Come check it out for yourself! The view into the cave is much better. Just don’t drop your camera!