Gross Domestic Product is a touchstone for growth and prosperity. However, this calculative practice is now dissonant with current natural resource depletion and social strife. The institutionalized social practice of NEA on which GDP is based, privileges flows over stocks under the untenable assumption that the stocks to fuel the flows are infinite. Various models of Genuine Progress Indices have been developed to better proxy community wealth to improve policy-making. Although some models monetize many of the natural, social and economic indicators, the values are not recorded on a balance sheet. If the core of intergenerational equity is community-asset maintenance and the mainspring in accounting is assets, a balance sheet to monitor community wealth is obligatory. A pilot methodology and balance sheet are proposed, and valuation techniques are illustrated using the case of Cancún's marine parks, vital to the economic and social fabric of the surrounding community.