Complex sentence: Without such a standard, data providers may be forced to provide different GIS data formats and different types of information to each council, often implying multiple files for each asset class (transport, sewer, drainage etc).
Split into simpler sentences: Without such a standard, consultants may be forced to provide data in multiple different GIS formats and to include different types of information for each council. They may need to supply multiple files for each asset class (transport, sewer, drainage etc).