There are several ways to do this.
How many values do you need to store for each tile? Will the set of values be the same for all tiles, or different? For example, water tiles will have "depth" value, ground tiles will have "walk_speed" and "solid" values etc.
Will there be many tiles without any values? You can think of a Tilemap as a 2D array, which stores tile type (ground, sand, water, rock). So you don't have to store this info in the array.
Do you need to store the array with all these values in the project, or will it be randomly generated in runtime?