The annual wet and dry seasons have a greater effect on the Mekong’s flow through Central Laos than in the Upper Mekong, and river levels and speed widely vary throughout the year. Rains from May to October produces a massive runoff from the Annamite Mountains’ major tributaries. The Mekong’s current becomes quite fast, and flooding often occurs at riverside villages, especially in Bolikhamxay where the river takes a tight southward turn.
However, by the end of the dry season from March to May, the Mekong returns to its lazy flow, and river levels drop up to 15 metres, exposing large rocks and sand bars, and creating sections of rapids. This presents challenges for boat navigation, even smaller longboats that tend to hug the shoreline.
These local boats continue to provide a significant method of commercial and passenger transportation and communication between riverside villages on both Mekong banks. This cross-river contact dates back hundreds of years to when Lao kingdoms dominated both sides of the Mekong, and continued though Siamese control in the 19th century. People in north-eastern Thailand speak the same language and dialect as Lao people across the Mekong, and many have family in both sides. To this day, small villages on the Mekong banks serve as local ferry ports for small cargo shipments and local passengers, who can receive border passes to visit relatives and purchase and sell goods.
In 1994, the 1st Thai-Lao Bridge opened, crossing the Mekong from Nong Khai, Thailand, to Vientiane. Until then, the only overland route from Thailand to the Lao capital required a ferry. The bridge opened up the isolated capital that had just begun to modernize. When the Lane Xang Kingdom moved the capital to Vientiane in the 16th century, this seclusion was of strategic defensive importance. The Mekong and surrounding moat fortified by an 8-metre-high brick wall up to 5 metres wide protected the capital from invaders.
Vientiane still has no major river port, and only a few luxury cruise lines call on the capital city and its well-known sites, using the Mekong Landmark Hotel as their landing. In 2016, officials started planning to construct a full-facility port near the hotel and the new Walking Street. Chao Anouvang Park dominates the city’s riverfront, highlighted by its Night Market. Cycling along the Mekong to villages in Vientiane’s outskirts has become popular. There are few dinner/sunset cruises for tourists in Vientiane, but locals enjoy floating restaurants and “karaoke boats” downriver in Tha Non Village. There is no scheduled public boat service to villages up and downriver.
Just past the capital city, The Mekong abruptly deviates to the north, as it enters Bolikhamxay Province. The Nam Ngum River, a major Mekong tributary, demarcates Vientiane and its eastern provincial neighbour. The Nam Ngum originates in Xieng Khouang Province’s mountains and is dammed in Vientiane Province. The Mekong continues north, skirting the Phou Khao Kwai National Protected Area, before veering east. It passes Vat Phonsane, known for the annual Bang Fai Phayanak Festival during October’s full moon, when mysterious coloured “Naga Balls” pop from the Mekong’s surface and disappear.
The Mekong then returns to heading south towards Pakxan Town, picking up the Nam Xan River, a sizeable tributary fed by Xieng Khouang’s mountains, on the way. Pakxan, a laid back town some 150 km from Vientiane Capital, handles local river traffic and cross-Mekong ferry service from its pier. A further 15 km downriver, the Mekong rumbles over a series of rapids, culminating at Tad Heua Hak (Wrecked Boat Rapids) before reaching Pak Kading and the Nam Kading River fed by a bowl-like mountain cluster in the Ka Ding Biodiversity Area. About 25 km downriver from Pakxan, the Mekong reaches Kaeng Sadok Village’s sandy beach, which serves local fishing boats that troll around oddly shaped boulders that crop up in mid-river trip.
The Mekong continues to Khammouane Province, where the Nam Hinboun drains into the increasing flow before reaching Thakaek, 185 km downriver from Pakxan. Thakaek mostly serves as a hub for tourists heading to the province’s inland natural and cultural attractions. Its pier launches cross-river ferries to/from Nakhon Phanom, but the 3rd Thai-Lao Friendship Bridge handles most of the cross-river traffic.
The Mekong’s steep, shady bank draws locals and Thakaek tourists to the tables and chairs lining the river road, with restaurants situated across the street delivering meals and refreshments. A sunset dinner cruise sails based on demand, but no cruise ships stop at Thakaek. The town retains its distinct ambience as a small 100-year-old port town, with a night market surrounded by French colonial structures converted into guesthouses, noodle shops, and small stores. Along the Mekong, near town, tourists can visit the 6th-century Sikhottabong Stupa, a nine-house cultural village, and the 9th-century Giant Wall (Kampaeng Yak). The Nam Theun River drains into the Mekong upriver from town.
As the Mekong continues downstream, it reaches the confluence with the Xe Bang Fai River, which originates in the Annamite Mountains, and forms the boundary with Savannakhet Province. Less than 130 km downriver from Thakaek, the Mekong reaches Savannakhet Town. The once sizeable French colonial port serves local Mekong traffic, but the cross-river service has lost traffic to the 2nd Thai-Lao Friendship Bridge, and no cruise ships stop at the pier. Though there are no dinner/sunset cruises or river-based activities, Savannakhet Town offers one-day tours along the Mekong. The “Savannakhet Downtown Tour” takes in 20 colonial-era structures, while the “Mekong River South Tour” presents a sacred stupa, weaving villages, and ancient Khmer rest house.
The Mekong then heads out on a long and lonely 245-km run to Pakse. The river picks up the waters from the Xe Pon River before breaking into Southern Laos at Salavan, where it runs along the sparsely populated, pristine Phou Xiang Thong Biodiversity Area, before breaking again from its border role with Thailand and into Champasak Province and the core of the Southern Mekong.