BELFAST — A small group gathered Oct. 8 near the Belfast boat launch, where the Climate Crisis Committee introduced its High Water Mark project and discussed other water monitoring projects, as well.

The High Water Mark project was developed and funded by Maine Silver Jackets and the U.S. Army Corps of Engineers. Two posts were placed, along with signs that display how high storm surges could get in best-case and worst-case sea-level rise scenarios. One is near the town boat launch and the other is at the corner of Front Street Shipyard’s property on the side closest to Front Street Pub.

Maine Silver Jackets brings together federal, state and local agencies to reduce flood risks and natural disasters, according to its website. It also works to enhance response and recovery efforts during such disasters. There are Silver Jackets teams in other states also.

The project was a collaboration among the city, the Army Corps of Engineers, the National Oceanographic and Atmospheric Administration, Maine Geologic Service and the Federal Emergency Management Agency.

On both posts, the bottom placard shows the storm surge measurement for a 1978 storm, the middle placard shows predicted storm surge in 2050 under one sea-level rise scenario and the top placard is the predicted storm surge in 2050 under another sea-level rise scenario. The post near the Belfast boat launch shows a rise of 12 feet by 2050 if emissions are lowered. Without lowering emissions, a rise of 13.9 feet is predicted. The storm surge of 1978 measured 10.3 feet.

The event was also a chance to talk about other water monitoring projects that have been installed in the bay. There are few coastal communities in Maine with even one water monitoring sensor, let alone three, according to Climate Crisis Committee Chairman Jon Beal. He is unaware of any other Midcoast community with as many water monitoring sensors as Belfast.

Belfast has a monitoring system that was developed by a local high school class using an Arduino microcontroller board and a Raspberry Pi microprocessor-based mini computer. Belfast Area High School student Jonah Lovejoy, 17, was one of the students who worked on the system last school year. It measures the water level in the bay at various times of day.

The Arduino system the students developed has not yet been tested for accuracy, so another, more sophisticated monitoring system funded by a Gulf of Maine Research Institute grant is located next to the Arduino and also measures water levels at various times.

The committee will compare data from the Arduino to data from the radar sensor and observe the accuracy of the Arduino’s measurements. If it is accurate, many coastal towns in Maine could use Arduino technology to measure water levels for about $100, Beal said. It could be a more affordable option than buying into a sophisticated sensor, which many towns cannot afford.

The third sensor was recently installed for a six-month pilot program the city just entered with Divirod facilitated by US Harbors. Placed near the boat launch, it uses satellite technology to monitor water levels in the bay. It is unclear if the city will pay for the service after the six-month pilot program ends.