The statement is true; East Maui's streams are mostly located on the windward side of Haleakala due to the rain shadow effect, which causes more precipitation on this side and leads to the creation of streams.
The statement that most streams in East Maui are found on the windward side of Haleakala is true. This phenomenon occurs due to the rain shadow effect which is observed when moist trade winds from the ocean encounter a mountain, such as Haleakala, resulting in rainfall on the windward side.
As a consequence, the windward side receives more precipitation leading to the formation of numerous streams. Meanwhile, the leeward side remains relatively dry, similar to the conditions found on the leeward side of Mount Waialeale in Kauai which creates a semi-desert due to the rain shadow effect.
So, the geography of mountainous islands like Maui and Kauai results in a specific distribution of precipitation and, consequently, stream formation primarily on their windward sides.