Around 1900, the government separated part of
Mueang Ratchaburi district and created a new district named Tha Nat Wat Pradu (ท่านัดวัดประดู่). The district office was in front of
Wat Pradu at the
Khlong Wat Pradu in
tambon Chom Prathat, today in Wat Phleng District.
Tambon Pak Tho was included in this district. As it was also near the Om River, the district was also known as Maenam Om (แม่น้ำอ้อม). Later the district office was found to be inconveniently located. During the dry season the water level in the canal was too low and there was no road connection. In 1914 it was moved to a new location in
tambon Pak Tho, near a railway station. The area around the old district office became the minor district Wat Phleng. On 10 April 1991, the district was visited by Crown Prince Maha
Vajiralongkorn. He was presented a petition by locals asking for help with local water resources, specifically the lack of water for farming. The crown prince passed along the need to the Royal Irrigation Department (RID) and other agencies. the district has five working reservoirs, a sixth in the planning stage, and Vajiralongkorn has ascended to the throne of Thailand. ==Geography==