Portland Maine King Tides Trail

Installation Description

Installation Concept

Installation Process

Students in the University of Southern Maine (USM) special topics course, ART 312 - Shaping the Terrain, consulted with USM graduate student Nathan Broaddus, Muskie School of Community Planning and Development to determine the location of a 3-foot sea level rise (SLR) line based on the observed highest annual tide for 2014. This provided a basis for creating the Portland Maine King Tides Trail. The trail follows the 3-foot line and meanders through and around Bayside and East End Beach Trails. It extends from Elm Street in Bayside neighborhood to Widgery Wharf in the Old Port.


The temporary installation designed to mark the trail incorporated the following components: (1) a series of circular graphics placed on the pavement at significant sites along the trail (2) red line whiskers used to mark a portion of the 3-foot SLR line that cut through a large, empty lot bordered by Somerset Street and Elm Street (3) a series of 28 King Tides Beacons (trail markers) made from blue wooden stakes, solar lamps and laminated signs.


Photo Credits: Amber Desrosiers and USM College of Arts, Humanities and Social Sciences






The installation was inspired by Japanese Tsunami markers, which mark the location of past Tsunami waves. The markers are a warning to pay attention to vulnerable sites. The King Tides installation was a contemporary version of Tsunami markers pointing to future rather than past, but issuing a similar warning.


The 3-foot sea level rise (SLR) line delineated by red line-marking whiskers cut through an empty urban lot slated for Portland’s Midtown Project, a large-scale apartment complex. According to a Portland Press Herald article, Somerset Street and the Bayside Trail will be raised above flood level from Pearl Street to Elm Street during construction. The King Tides Trail installation highlighted features of this industrial site, which was previously part of the Back Cove tidal basin. One of the significant features on the lot was named Midtown Lagoon; it is a marshy area reminiscent of the wetlands that were once there.


The installation was informed by the research of marine geologist Peter Slovinsky, who points out that the latest scientific predictions for SLR are 1 foot by 2050, 2-3 feet but potentially more by 2100. The State of Maine has adopted 2 feet as a middle-of-the-road prediction by the year 2100 for areas with regulated Coastal sand Dunes. Slovinsky suggests examining scenarios of 1 foot, 2 feet, 3.3 feet and 6 feet on top of the highest annual tide (HAT). These scenarios relate to the National Climate Assessment, and also correspond well with evaluating potential impacts from storm surges that may coincide with higher tides today.


The aim of the King Tides Trail was to illuminate these potential impacts through artistic visualizations and processes. Students assumed the roles of cultural workers and environmental monitors. Their choice of materials reflected the collaborative nature of the project, where no singular aesthetic voice dominated; rather, they worked collectively with the intention to develop cohesive visual forms that conveyed a message about SLR.

After receiving concept approval by Portland's Art in the Park Student Temporary Public Art Program, the class ordered materials and created a time line for completing the installation. When final approvals and permits from the city were granted, red line-marking whiskers were attached to 60-penny nails and pounded directly into the ground to mark a section of the 3-foot sea level rise (SLR) line. Line marking methods were tested earlier in October when blue surveying flags were used to delineate a different portion of the 3-foot line at the King Tide MoonTide Garden Party in Portland. Hand-held GPS receivers enabled students to accurately determine the location of the line, which had been projected using Geographic Information Systems (GIS) software in the USM/GIS lab.


Beacons (blue stakes topped with solar lights and incorporating  laminated signs) were installed by hand. A GIS map helped determine Beacon locations, which were placed near sites that will flood with a 3-foot SLR rise. The signs pointed the way to the trail and incorporated a QR code that resolved at the Portland Maine King Tides Trail Google Map.


Members of the public were invited to join in the official opening of the King Tides Trail on Monday December 8 at 12 noon. The celebration included a trail walk beginning at the Bayside Trail’s western terminus at Elm Street near the intersection of Somerset Street.


The installation received media coverage in the Portland Press Herald and the Forecaster. It was featured on Maine Public Radio's Maine Things Considered and on WMPG talk radio. Instagram and Facebook sites were also created to expand the audience for the installation and trail.