Traverse City sits at the head of Grand Traverse Bay where the Old Mission Peninsula divides the bay into two long, deep arms that extend north into Lake Michigan. The water level dynamics there are unusual because the deep narrow geometry of the arms produces some of the largest seiche signals on Lake Michigan and because two distinct shorelines, East Arm and West Arm, meet at the city. I am Chris Izworski. I live in Bay City, I travel to the Grand Traverse region for both fishing and family reasons, and I treat the bay as part of my regular Michigan working knowledge. This page is the orientation for Traverse City property owners and visitors.
Grand Traverse Bay is a glacial trough that opens north into Lake Michigan and is split by the Old Mission Peninsula into the East Arm and the West Arm. The arms are similar in length, both roughly thirty miles from the head of the bay at Traverse City to the open Lake Michigan connection. The depths are substantial, with maximum depths of 615 feet in the West Arm and 550 feet in the East Arm. The chart datum for both is the Lake Michigan and Huron datum, and the long-term water level at Traverse City equals the Lake Michigan and Huron stage at Mackinaw City almost exactly. The local NOAA gauge is the Holland or Ludington station for Lake Michigan stage, but for practical Traverse City purposes the Mackinaw City reading is closer.
The two arms behave differently in storm conditions. North wind drives water and wave energy down both arms equally. West wind drives water against the East Arm shoreline at higher intensity because the West Arm absorbs and dissipates the wave energy first. East wind, which is rare, does the reverse. Local seiche signals can produce eighteen-inch oscillations at the Traverse City waterfront when conditions are right, particularly after the passage of strong west to east frontal systems.
The West Arm shoreline from Traverse City north to Old Mission is a mix of sand beaches, clay bluffs, and developed residential frontage including the historic Bowers Harbor community. The clay bluffs are the most level-sensitive feature on this shore. High water cycles undermine bluff toes and produce episodic bluff loss events. The 2019 to 2020 high stand produced documented bluff failure along several West Arm properties, with some structures losing significant setback distance to the lake. The Old Mission Peninsula vineyard industry, concentrated on the high ground above the bluffs, is not directly affected by lake level but depends on the broader Grand Traverse tourism economy that the bay itself sustains.
The East Arm shoreline runs north from Traverse City along the east side of Old Mission Peninsula and connects through to the Elk River and Chain of Lakes system at Elk Rapids. Elk Lake and Torch Lake, the two largest lakes in the Chain, drain through the Elk River into the East Arm. The chain of inland lakes is hydrologically distinct from Lake Michigan, but the Elk River discharge connects them and the river mouth at Elk Rapids takes on Lake Michigan stage in its lower reach.
Clinch Park on the Traverse City waterfront fronts the head of the bay and is the visible municipal interface with the water. The Clinch Park beach has contracted and expanded through every recent cycle. The Open Space, the larger municipal park east of Clinch Park, has more elevation and is more level-tolerant. The Hotel Indigo and other recent waterfront developments have been engineered with the post-2020 high water envelope in mind, which is a useful indicator of how the local planning culture has internalized the most recent cycle.
The Boardman River discharges into the head of the bay through downtown Traverse City and provides the only significant local freshwater input to the West Arm head. The river has been the subject of significant restoration work over the past decade, including the removal of the Brown Bridge, Boardman, and Sabin dams to restore a free-flowing reach from Boardman Lake to the bay. The river mouth at the Cass Street Bridge takes Lake Michigan stage and the lower river is essentially a backwater of the bay.
The Clinch Park Marina and the Duncan L. Clinch Marina at the head of the bay have weathered the recent extremes by progressive dock work. Private dock owners along both arms should plan structures with the full Lake Michigan envelope in mind.
Traverse City does not have its own NOAA water level gauge. The closest operational stations are Mackinaw City to the north and Ludington to the south. For most Traverse City planning purposes the Mackinaw City station 9075080 is the appropriate reference because it captures the same northern Lake Michigan and Straits stage that propagates into Grand Traverse Bay through the open north connection.
I cover the wider northern Lake Michigan picture on the Northwest Michigan and Lake Michigan pages. Questions specific to Traverse City can reach Chris Izworski through chrisizworski.com.