This is a large open green space, bounded by the Clyde, the Leven, and Levengrove Park. An ideal site, from WDC point of view, to build a new school. A campaign against this is mounting, and there is now a 'Save Postie's Park' site on Facebook.
There is also a petition .
In brief, this would be against WDC adopted Local Plan (listed as retained public open greenspace) and has some relevant European environmental legislation (redshanks on the shore) a great deal of public opposition and a reasonable alternative - the existing site.
The National Pipe Band Championships (or any similar open air events) would also not be held here after 2015; it is an ideal site and is probably Dumbarton's major event.
WDC have done test drilling, and a report goes back to the Education Committee in September. This has to be followed (if they confirm their preference) by a Pre-application Consultation (comments by the public must be noted), a planning application (formal objections must be heard), and finally, because the land is owned by WDC and is against their own Local Plan, it will be called-in by the Scottish Government, for a final decision by a Reporter (all comments, objections, etc. etc. must be taken into consideration).
Postie’s Park was given to the local authority in 1872 in substitution for rental sums due to the Town Council, and (unfortunately) does not form part of Dumbarton Common Good. Protection therefore rests on the Adopted Local Plan being respected. Comments can be made at the Pre-application stage, and formal comments at the Planning Application stage, although there is nothing to stop individuals writing to their local councillors at this stage.
Clydebelt’s committee will be objecting to the choice of this site to WDC. See also http://www.lennoxherald.co.uk/dunbartonshire-news/dunbartonshire-news/dumbarton-news/2013/06/07/bill-heaney-posties-is-the-people-s-park-114557-33426517/ and other press comment.