Starting in 1989 the Archivio storico del Patriarcato di Venezia (Historical Archives of the Patriarchate of Venice) carried out a project to safeguard and to inventory the historical archives of the diocese, with the aim to preserve the fonds and to make them accessible to researchers.
The project, called Arca, is part of a larger one with the aim to create an information system of the historical archives of the Venetian Churches with the project Ecclesiae Venetae, promoted by Ministero per i beni e le attività culturali (Ministry for the Cultural Heritage and Activities) and the Veneto Regional Administration itself and other five Venetian Dioceses. It is also supported by the meaningful financial aid of other institutions involved in the preservation of the cultural heritage of Venice, such as the Gladys Krieble Delmas Foundation through the Save Venice Inc. di New York.

The archival fonds involved in the project include the archives of the Curiae and others connected to it, such as these of the Mensa Patriarcale (the revenues of the bishop) and the Seminar, with numerous associated fonds of the Chapter and Primicerius of St. Mark, including the documents of the Chapter of the ancient Cathedral of San Pietro di Castello; the ancient episcopates of Grado, Caorle and Torcello.
It is also another integral and valuable part of the project the inventory of the ancient archives of the parish churches of the dioceses, according to a plan still accomplished for the historical area of Venice, an now expanding to the churches of the Lagoon, of the coast and of the “Terraferma”(dry land). The various archives associated to the parish one are described too: from those of the parishes suppressed by the Napoleonic administration, to the fonds of the vestry-boards of 800’s and 900’s, to the documentation of the lay confraternities, «scuole» or guilds and parish associations.

Other fonds, as those of the ecclesiastical confraternities, such as the congregations of the clergy from Middle Age, and more recent association as the Catholic Action of the diocese, as well as the personal document of some priests and laymen, are part of the ecclesiastical archives of Venice.
The description is matched with a critical review of ecclesiastical history and the draft of updated historical and administrative profiles, especially for the numerous parish churches and confraternities of the diocese.
The full data base, which so far comprises around 36,000 record entries, is a complete uniary information system of the outstanding archives of the Church in Venice, including those collected in the Patriarchal Archive and those kept in their seats, as the Seminar and some parish churches.

Other fonds, as those of the ecclesiastical confraternities, such as the congregations of the clergy from Middle Age, and more recent association as the Catholic Action of the diocese, as well as the personal document of some priests and laymen, are part of the ecclesiastical archives of Venice. The description is matched with a critical review of ecclesiastical history and the draft of updated historical and administrative profiles, especially for the numerous parish churches and confraternities of the diocese. The full data base, which so far comprises around 36,000 record entries, is a complete uniary information system of the outstanding archives of the Church in Venice, including those collected in the Patriarchal Archive and those kept in their seats, as the Seminar and some parish churches.
A diagram showing the archives included, their internal organization and the premises where they are conserved can be seen on page Archivio storico del Patriarcato di Venezia - Patrimonio (Historical Archives of the Patriarchate of Venice)