This town grew rich on salt fields spread along the shore. In the latter half of the Edo era, one person, over more than three years, completed in the north of the town vast salt fields that drew in seawater by the ebb and flow of the tide. The salt production of this land came, at one time, to about half the nation’s, and enriched the domain’s finances. When salt-making was in time reorganized and abolished, a large coastal industrial zone was built on the salt-field land and the like, and the town changed its figure into an industrial land. And it became the Shikoku-side gateway of a long bridge linking Honshu and Shikoku. As the land enriched by in-tide salt fields, this town did not join the Heisei mergers but walked on its own, and has lost population. Sakaide’s numbers are the record of a town carved by the history of salt fields and a bridge gateway.
A city that opens upon a land facing the Seto Inland Sea in the central part of Kagawa Prefecture. The population fell from 59,228 in 2000 to 50,624 in 2020. This city did not go through the Heisei mergers but walked on its own, so its recent population course has no merger-derived step. What I (Atlas) want to read here is not the sign "a city in the prefecture’s center," but the causal thread: how the history — salt fields and a bridge gateway — is translated into today’s population and finances.
01 · Seeing the present Sakaide in its numbers
In the 2020 Population Census this city’s population is 50,624, a little past fifty thousand. This city did not go through the Heisei mergers but walked on its own, so its recent population course has no merger-derived step. From 59,228 in 2000, through 57,266 in 2005, 55,621 in 2010, 53,164 in 2015, to 50,624 in 2020, some nine thousand fell over twenty years.
Looking inside, the figure of a town of salt fields and a bridge gateway gently raising its age appears. The share aged 65 and over was 35.9% in 2020, passing three in ten. The household-with-children share was 18.9% in 2020, and the crude birth rate was 5.3 per thousand in 2020. The Childcare Waitlist was zero in both 2024 and 2025. The Fiscal Capacity Index was 0.78 in fiscal 2023 — a thick level for a regional city, able to cover nearly eight-tenths of expenditure with its own tax revenue. The figure of the land enriched by in-tide salt fields, losing population just so on its own without a merger, appears in the numbers. Why it takes this shape cannot be read without going back over the history of salt fields, the industrial zone and the bridge.
Source: Population Census (Statistics Bureau, MIC) / Local Government Finance Survey, Fiscal Capacity Index (MIC) / Childcare Facility Status Report (Children and Families Agency) / Real Estate Information Library (MLIT)
02 · The in-tide salt fields, salt to industrial land, the bridge’s Shikoku gateway, the solitary course — the history behind the numbers
This town’s skeleton is set by the history of in-tide salt fields, the turn from salt to industrial land, the Shikoku-side gateway of a long bridge, and its solitary course. The starting layer is the salt fields. In the latter half of the Edo era, one person, over more than three years, completed in the north of the town vast salt fields that drew in seawater by the ebb and flow of the tide. The salt production of this land came, at one time, to about half the nation’s, and enriched the domain’s finances. The shoreline salt fields were this town’s foundation.
These salt fields changed their figure into industrial land. When salt-making was in time reorganized and abolished, a large coastal industrial zone was built on the salt-field land and the like, and the town changed its figure into an industrial land. And when a long bridge linking Honshu and Shikoku was built, this town became its Shikoku-side gateway. The road by which it became a city mirrors this town, too. In the middle of the Showa era it took city status, and even as Shikoku’s leading industrial cities widened their scale in the Heisei mergers, it did not join them but walked on its own. The in-tide salt fields, the turn from salt to industrial land, the bridge’s Shikoku-side gateway, and the solitary course — this town’s shape stands upon the history of salt and industry, of the wealth that shoreline salt fields built.
Source: Sakaide City / the in-tide salt fields (Kume Eizaemon [Michikata] began the work in 1824 and completed broad in-tide salt fields in the north of the town; Sakaide’s salt production came to about half the nation’s and supported the finances of the Takamatsu domain — overview) / Sakaide City / the Great Seto Bridge and Bannosu (the Shikoku-side gateway of the Great Seto Bridge; the Bannosu coastal industrial park [reclaimed 1965-1972] spreads over the former salt-field land abandoned in the reorganization of the salt industry — overview) / Sakaide City (in central Kagawa, facing the Seto Inland Sea; took city status in 1942 by merging Sakaide Town and others; as Shikoku’s leading industrial cities widened their scale in the Heisei mergers, it carried out no merger and continued on its own — overview)
03 · In the land enriched by in-tide salt fields, losing population just so on its own
What characterizes Sakaide is that, while holding the history of salt fields and a bridge, it loses population on its own without a merger. From 59,228 in 2000 to 50,624 in 2020, some nine thousand fell over twenty years. Even in this town that changed its figure from salt fields to industrial land and became a bridge gateway, one can read that a part of the young generation has moved toward larger cities and the age of the whole town has risen. That the share aged 65 and over reached 35.9% in 2020, past three in ten, is one expression of this.
On the other hand, the Childcare Waitlist was zero in both 2024 and 2025, the household-with-children share was 18.9% in 2020, and the crude birth rate was 5.3 per thousand in 2020. A Fiscal Capacity Index of 0.78 is a thick level for a regional city, able to cover nearly eight-tenths of expenditure with its own tax revenue. The population fell by some nine thousand over twenty years, and aging too passed three in ten. That it nonetheless keeps its fiscal strength on the thick side for a regional city is because the coastal industrial zone built on the former salt fields supports the tax revenue apart from the number of people living there. The work of burning salt is gone, but the very land that was leveled flat works on, having changed its figure into another source of wealth, industry — Sakaide’s strength appears rather in the carrying-on of this land than in the level of its population.
Source: Population Census (Statistics Bureau, MIC) / Local Government Finance Survey, Fiscal Capacity Index (MIC) / Childcare Facility Status Report (Children and Families Agency)
04 · A town where salt fields turned to industrial land, thinning on its own
In Sakaide, the same single tract of shoreline changed its role from salt fields, to industrial land, to a bridge gateway. One is the history of a land of in-tide salt fields that used the ebb and flow of the tide and at one time produced about half the nation’s salt. Another is the character of an industrial land, where, after the reorganization of salt-making, a coastal industrial zone was built on the salt-field land and the like. And it has the face of a bridge gateway, having become the Shikoku-side gateway of a long bridge linking Honshu and Shikoku. The in-tide salt fields that used the ebb and flow of the tide produced, at one time, about half the nation’s salt. On their former land a coastal industrial zone arose, and in time the Shikoku-side gateway of a bridge linking Honshu and Shikoku opened.
Salt fields, industrial land, bridge — the same shoreline land has been carried on, changing its role age by age. In the north of Kagawa, looking out toward Honshu, Sakaide’s outline is made not of a chosen terrain but of the overlap of a single tract reread again and again.
Source: Sakaide City / the in-tide salt fields (Kume Eizaemon [Michikata] began the work in 1824 and completed broad in-tide salt fields in the north of the town; Sakaide’s salt production came to about half the nation’s and supported the finances of the Takamatsu domain — overview) / Sakaide City / the Great Seto Bridge and Bannosu (the Shikoku-side gateway of the Great Seto Bridge; the Bannosu coastal industrial park [reclaimed 1965-1972] spreads over the former salt-field land abandoned in the reorganization of the salt industry — overview) / Sakaide City (in central Kagawa, facing the Seto Inland Sea; took city status in 1942 by merging Sakaide Town and others; as Shikoku’s leading industrial cities widened their scale in the Heisei mergers, it carried out no merger and continued on its own — overview)
05 · Atlas’s note — reading Sakaide from the carrying-on of a single tract
Lay out Sakaide’s numbers and, while indicators of a thinning population line up — a population falling just so on its own, an aging rate of 35.9%, a household-with-children share of 18.9% — a number thick for the population scale is mixed in: a fiscal capacity of 0.78. But what I want to trace, more than the line of indicators, is the path by which the old foundation of wealth, the shoreline salt fields, was reread, with the end of salt-making, into a new foundation, a coastal industrial land, and that flat-leveled tract was carried on across the ages. The broad shoreline made flat for burning salt was reread, after salt-making, as land for industry. The chain — that a tract once leveled became the foundation of the next industry — explains this town’s numbers well.
The other thing I want to consider is that, while the population falls, the fiscal capacity is thick for a regional city at 0.78. This can be read as an expression of the coastal industrial zone, built on the former salt fields, being the foundation of employment and tax revenue. The coastal industrial zone on the former salt fields supports employment and tax revenue, and the position of being the Shikoku-side gateway of the bridge also holds the strength of a passage for people and cargo. The thickness of an industrial and locational foundation, not measurable by the number of population alone, appears rather in the figure of the finances. The shoreline leveled flat for burning salt became, after salt-making, just so the vessel of a coastal industrial zone. That Sakaide’s fiscal capacity is kept thick for its population scale is likely because this carrying-on of the tract, and the position as the Shikoku side of the bridge crossing to Honshu, work upon it. Whether, from there on, to find in that thickness a footing for life I would leave to the reckoning of the one who lives here.
Source: Population Census (Statistics Bureau, MIC) / Sakaide City / the in-tide salt fields (Kume Eizaemon [Michikata] began the work in 1824 and completed broad in-tide salt fields in the north of the town; Sakaide’s salt production came to about half the nation’s and supported the finances of the Takamatsu domain — overview) / Sakaide City / the Great Seto Bridge and Bannosu (the Shikoku-side gateway of the Great Seto Bridge; the Bannosu coastal industrial park [reclaimed 1965-1972] spreads over the former salt-field land abandoned in the reorganization of the salt industry — overview) / Sakaide City (in central Kagawa, facing the Seto Inland Sea; took city status in 1942 by merging Sakaide Town and others; as Shikoku’s leading industrial cities widened their scale in the Heisei mergers, it carried out no merger and continued on its own — overview)
Editor’s note: all figures and sources are drawn from official statistics. The prose follows Atlas’s voice, and AI (atlas-handcrafted-reverse-v1 (wave-cs1 2026-06-05)) handled the shaping of the text. Evaluative or predictive language (such as “a good buy” or “attractive”) is intentionally left out. Revision id: wavecs1_