Who Does What; How and When?

The simple answer to this question; there isn't one.  Its complicated.

IslandWalk and Gran Paradiso are just 2 of 9 planned "villages" in what is known to urban planners as a "village district".  Village districts are thought to be more sustainable than the urban/suburban sprawl that characterized growth in the 50 years following World War II.  Both Sarasota County and the City of North Port have adopted the village district concept for future growth, and this was applied to our own WVID.
The "pattern book" for the West Villages was developed between 2001 and 2004 by Fourth Quarter Properties and city planners. It is a "living document" in that it is continually reviewed and amended by both the developer and the City in response to changes in conditions as time goes by.  It is a comprehensive and detailed plan of where villages, parks, utilities, public service centers, and town centers are located.  It provides for a network of secondary roads that interconnect all parts of the district. It includes detailed specifications and standards to ensure that the "look and feel" of the district is uniform throughout all the villages, road ways, and town center.
WVID was created by the Florida State Legislature in 2004.  Via its 5 member elected Board of Supervisors, and paid staff of managers, attorneys, and engineers, it provided the initial budget and schedule of infrastructure improvements to be made. The WVID raised funds by issuing public bonds. It maintains district infrastructure and pays down the bond debt by non-ad valorem tax assessments of property owners within the district.  It is responsible for the day-to-day business of the district, and for all planning, contracting, and oversight of infrastructure improvements required in the district's Pattern Book for development..

This excerpt from the City of North Port's website should answer most questions:
Pattern Books, Pattern Plans & Index Maps - In the late 1990's and early 2000's, North Port city planners created a master planning process for large, mixed residential and commercial developments called the Village District. The goal behind its creation was to require developers to plan for every aspect of these large developments. Concurrently with construction of homes and businesses, Village District developers are required to construct the infrastructure to serve the development. An equally important goal of the process was to ensure that provision of municipal services to these developments does not place a burden on City taxpayers who do not reside there. A Village District developer is required to produce three types of planning documents for the City's inspection and approval:  the Village District Pattern Book, the Index Map and the Village District Pattern Plan. On a City-wide scale, the Comprehensive Plan, the Future Land Use Map and the City's Land Development Code together provide guidelines and regulations that govern all development in the City. On the smaller scale of a Village District, the Pattern Book, Index Map and Pattern Plan serve similar functions. Pattern Books, Index Maps and Pattern Plans for Heron Creek and the West Villages developments are available for public inspection at the Planning, Zoning and Engineering Department.
The WVID "Index Map" is available to view on-line by clicking HERE.