Coastal cities grow much faster initially then inland cities – access to the sea can give international access to sea borne trade, a leisure and tourism draw and increased value of coastal housing.
However that growth slow down more quickly, as they hit limits to growth in their hinterland, such as flood risk from their low elevation and in many areas rugged, scenic and/or undevelopable areas. Given they typically have half the hinterland because of sea where there are constraints coastal settlements hit them earlier. The end to growth leads to an aging population, higher house prices, lower productivity, lower wages for low skilled occupations and lower economic growth.
Many coastal communities however are in a double bind as they often have close rail or other transport connections to major and capital cities further down a coast or estuary. The lowering of house prices because of weak local economic growth makes them more and more relatively attractive to those forced further and further out from these metropolitan areas in order for housing to be affordable. The double bind being a weak local wages growth combined with increasing house prices and lowering affordability..
Productivity growth is increasingly dependent on fast growing cities, economies of agglomeration and innovation, larger labour markets and quality of life attracts innovative and creative people and firms attracted by ‘urban living’.
Hence coastal areas have a shortage of cities problem creating critical problems of affordability and regeneration, if not rich enough or unable to build Hong-Kong /Shanghai type towers they must grow outwards or spawn new cities on or near the coast to grow economically, which require strong sustainable transport networks, comprised of a network of ‘urban living’ areas, areas of a density and connectivity to ensure daily living, for a pint of milk or to go to school or commute, does not force unnecessary car-use, and avoiding the sprawl that can destroy the qualities of coastal and coastal hinterland areas that make them attractive places to live. This ensures that such growth is not strangled growth through congestion and create the productivity and innovation that sustains economic growth. This requires new connected cities – New Sustainable Garden Cities.
Greater Exeter: The latest combined OAN figure is 2660 per year, so by 2050 that means a total need of about +85,000 homes (32 years 2018 – 2050). There are around 28,000 homes already committed in local plans and existing planning permissions, leaving around 57,000 by 2050. S Around7 – 8 Cranbrooks). Some radical ideas will need consideration including linking major settlement growth and new settlements, including on the Exmouth line, to the reopening of the old main line north of Dartmoor, the Dawlish diversion (never finished) , the reopening of the Teign Valley line and restoration of track doubling to Crediton.
The Thames Estuary, South Essex and Kent Thameside: Over 90,000 new homes over and above what is in current local plans will be needed in South Essex alone by 2040. The potential to dig an extra tunnel for rail at the same time as the Lower Thames River Crossing could be transformational here creating the potential to link the two arms of Crossrail to form a Kent Essex Rail.
San Francisco the classic example of a coastal city with growth problems. Almost every square inch of developable coastal plane for many miles is developed right up to the edge of mountains, forests and protected coastal reserves. Going upwards in many areas is the only option if downzoning hadn’t made this impossible. Regionally there is one area where strategic expansion could happen. On the route of the old Sacremento Northern line on the almost uninhabited prairie between Anticoh and Sacremento. Built as a high speed line with eight trains a day it survives and is in the hands of a railway preservation group which has restored a section. An eastwards branch could link to Isleton and the old line of the Sacremento Southern Railroad. In this huge and bleak area there is space for no less than 8 Francisco sized cities. Who says there is a shortage of land in Claifornia, there is only a shortage of bold planning.
Auckland and Northland: The critical housing shortage in Auckland New Zealand is a livewire political issue. Its location not just on teh coast but an ismus makes expansion difficult. meanwhile the rail line along the ismus (Northland) is threatenened with closure served by only a number of small towns. The new government has promised to save it and build a new branch to serve a new port at Marsden Point, where there is the potential to build a new coastal high density city on a flat unprotected coastal plane. Also several key points on the North Auckland line further Southwards could take new citoes securing the population to make the North Auckland line viable.