river in Anhui and Jiangsu province
溧 is a rare kanji that names a specific river in Anhui and Jiangsu provinces. Its meaning is purely geographical and has no broader conceptual center.
溧 combines the water radical 氵 with 栗, which likely contributes the sound. It is a specific river name, and the exact historical development of this character is uncertain.
The water radical 氵 beside 栗 suggests a river associated with chestnuts (栗), perhaps one lined with chestnut trees. Picture the 溧 River flowing through a chestnut grove.
For リツ, imagine the river's current making a rhythmic 'ritsu, ritsu' sound as it flows over stones: ritsu -> リツ.
—