The Mae Kok River is large enough for long-tail boat rides year-round, and even has some islands and a beach just west of town (Hat Chiang Rai or Pattaya Noi). Pattaya Noi offers a pleasant stretch of beach with a beautiful mountain view with numerous small open-air restaurants and bamboo bungalo-type structures to relax in. There're also a few streams, like the Satarana-suk and the Mae Gon at the south end of town. The Mae Gon stream holds small boats during the rainy season. So do the Ing, Mae Suai, etc. The Mekhong runs a good distance along the border, taking in water from several smaller rivers. The small Mae Jaan River goes to Chiang Saen, joining the Mae Nam Kam and taking that name. The Mae Lao comes up from the south through Mae Suai, the Mae Suai flows into the Mae Lao, and the small Ing River flows north from Phayao Province, through Thoeng & Phaya Mengrai and into the Kok by Wiang Kaen.

There're many small lakes here and there throughout the countryside, including lots of pleasant reservoirs and a beautiful artificial lake at Suan Somdet Ya, behind Rajapat Institute. The Chiang Saen Lake, over a square kilometer in size, offers a variety of rental boats, and Tham Sao Hin (Phyanak Reservoir or Sleeping Lady Lagoon), though small, has some too. Swimming seems generally to be considered a recreation for children and teenage boys.

Chiang Rai municipality has a public water system with safe, clean, chlorinated water piped to homes. The Water Supply office on Kaisornrasit Road, below the Provincial hall, offers coin-operated water-dispensing hoses.

In the north, as in the rest of Thailand, people often drink bottled water. Maybe not in the countryside, where most people get their water from wells (usually with electric pumps), but most city people buy it from pick-up trucks that come around with big bottles. These range from 5 to 20 baht each, but are usually B10, for 20 liters. One must first put a deposit on one of the returnable bottles, at 70 to 200 baht (usually 80 or 90). This water is filtered tap water.

In stores one often finds more expensive water, in sizes from 7 ounces up to about a gallon. Usually a cooled plastic bottle, about a liter of water cleaned by reverse osmosis, is 5 or 10 baht. The imported kind is naturally more. Two liters top shelf, 35 or 40 baht, room temperature. It's name notwithstanding, Yellow Surprise is as good as most. Perhaps 'Sunrise' was meant.