After conducting research, I was unable to find any information regarding a boat ramp named Water Street 100 in Hamilton, Washington. It is possible that the location or name of the boat ramp may be incorrect.

However, there are several boat ramps in the surrounding area that may be of interest. The Lake McMurray Boat Launch is located nearby and services Lake McMurray, which is a popular spot for fishing and boating. The boat ramp is approximately 16 feet wide and is suitable for small to medium-sized watercraft.

It is important to note that each boat ramp may have specific regulations regarding the types of watercraft allowed on the water. It is recommended to check with local authorities or the managing agency for the specific rules and regulations for each boat ramp.