has the following responsibilities:
1. Improve the drainage efficiency of canals and water sources in solving flood and drought.
2. Construction of dams along the canal to prevent flooding in Bangkok
3. Develop pleasant canals landscape, and create public participation in the caring and maintenance of canals and preserve water culture and traditions
4. Canal garbage collection, water hyacinth, weed in ditches and waterways.
5. Maintenance of drainage conditions of ditches, canals, water retention ponds, and protecting structures in ditches, canals and public water sources
6. Considering and permission for structures/buildings through canals and water bodies
7. Perform other related duties or assigned

The division consists of: 1. General administration Section
1. Correspondence and general administration
2. Administration and coordination work
3. Procurement
4. Staff and discipline work
5. Finance and budget
6. Public relations
7. Supervision and facilitate of office premises and vehicles
8. Perform other related duties or assigned.

2. Canal System Development Section1
1. Improve the drainage efficiency of canals and water sources in solving flood and drought
2. Construction of dams along the canal to prevent flooding in Bangkok
3. Develop pleasant canals landscape by means of construction
4. Considering and permission for structures through canals and water bodies, resolving various complaints related to canal from the private sector and other agencies
5. Perform other related duties or assigned This section is responsible for 28 districts including Dusit ,Ratchathewi, Phayathai, Bang Sue, Chatuchak, Bang Khen, Lak Si, Don Mueang, Din Daeng, Sai Mai, Huay Kwang, Bueng Kum, Bang Kapi, Minburi, Khlong Sam Wa, Lat Phrao, Nong Chok, Saphan Sung, Wang Thonglang, Prakanong, Suan Luang Prawet, Ladkrabang, Bangna, Wattana, Khlong Toei, Pathumwan , Khan Na Yao

3. Canal System Development Section 2
This section has the same authorities as the Canal System Development Section 1 but it is responsible for 22 districts : Pranakorn, Pom Prap Sattru Phai, Samphanthawong, Bang Rak, Yannawa, Sathorn, Bang Kho Laem, Khlong San, Thonburi, Chom Thong, Thung Khru, Bang Khun Thian, Bang Bon Rat Burana, Bang Phlat, Bangkok Noi Bangkok Yai, Talingchan, Bang Khae, Phasi Charoen, Nong Khaem and Thaweewattana

4. Canal System Development Section 3
This section has the same authorities as the Canal System Development Section 2 but it is responsible for 6 districts, namely Nong Chok, Min Buri, Prawet, Lad Krabang, Saphan Sung, and Klong Sam Wa.

5. Canal System Development Section 4
This section has the same authorities as the Canal System Development Section 3 but it is responsible for 15 districts, including Klongsan, Chom Thong, Taling Chan, Thaweewattana, Thung Khru, Thonburi, Bangkok Yai, Bangkok Noi, Bang Khun Thian, Bang Khae, Bang Bon, Bang Phlat, Phasi Charoen, Ratburana and Nong Khaem.