Complex sentence: Two major tributaries account for nearly 60% of inflow by streams or rivers into Utah Lake with the Provo River accounting for 36% of the inflow and the Spanish Fork River accounting for 24%.
Split into simpler sentences: Two major tributaries account for nearly 60% of inflow by streams or rivers into Utah Lake. The Provo River accounts for 36% of the inflow, and the Spanish Fork River accounts for 24%.