The fishing community in Thailand has a tendency to talk about the same destinations repeatedly. Bhumibol gets mentioned. Mae Ngat gets mentioned. But Sirikit Reservoir — sitting quietly on the Nan River in Uttaradit province, a few hours north of Phitsanulok — rarely makes the shortlist. That oversight belongs to the serious angler's advantage.
A Reservoir Built on a Great River
Sirikit Dam was completed in 1974, impounding the Nan River to create a reservoir stretching approximately 60 kilometres through the valleys and forested hills of Uttaradit and Nan provinces. Named in honour of Queen Sirikit, the dam was built primarily for flood control and hydroelectric generation — functions it continues to serve. The reservoir it created, covering roughly 260 square kilometres at full capacity, has spent the intervening decades developing into a functioning wild ecosystem.
The Nan River is one of northern Thailand's defining waterways, running from the mountains near the Lao border southward to join the Chao Phraya system in the central plains. Its upper reaches remain among the more intact wild river habitats in the country. The reservoir captures water from this relatively well-preserved catchment, which contributes to the quality of fish populations within it. These are wild fish in a genuine sense — inhabitants of a system shaped by natural processes, not management interventions.
Sirikit Reservoir receives significantly less recreational fishing pressure than reservoirs closer to major population centres. This contributes to better fish populations in many areas, but it also means less local infrastructure for visiting anglers. Come prepared and arrange a guide well in advance.
The Resident Species
Featherback are perhaps Sirikit's most iconic resident. The giant featherback (Chitala lopis) and its relative the clown featherback (Chitala ornata) both occur here, inhabiting the weedy bays and submerged structure throughout the reservoir. These prehistoric-looking fish — laterally compressed, covered in intricate patterning, capable of reaching substantial sizes — are extraordinary catches anywhere they occur. At Sirikit, populations appear healthier than in more heavily pressured systems. Read our full guide to giant featherback for more on identification, behaviour, and responsible handling.
Giant snakehead are the dominant predator in the reservoir's arms and flooded margins. This is classic giant snakehead habitat — complex, woody structure in protected bays, warm shallow water, and an abundance of prey fish to sustain large individuals. Surface lure fishing for these animals is Sirikit's marquee attraction for visiting anglers. The takes are violent, the runs powerful, and the fish — in a reservoir that sees relatively modest pressure — are less educated than those in more accessible waters.
The native catfish suite is excellent. Yellow catfish (Hemibagrus nemurus) are present in good numbers and respond well to natural baits fished on the bottom. Chao Phraya catfish occupy the deeper central channel areas. Wallago — the predatory, fast-swimming catfish with the deeply forked tail — occur throughout and occasionally surprise anglers targeting other species with aggressive strikes on mid-water presentations.
Featherback in Sirikit's weedy bays have spent decades in a reservoir shaped by natural processes, not management. They move differently, fight differently, and matter differently from fish raised in a stocked lake.
Reading the Water
Sirikit is not a simple reservoir to fish without local knowledge. The Nan River's submerged valley creates a complex underwater topography — drowned channels, submerged terraces, flooded vegetation zones — that holds fish in specific ways that change with water level and season. A guide who knows the reservoir through accumulated seasons is not a luxury but a practical necessity.
The upper arms of the reservoir, where the Nan River and its tributaries feed in, tend to be most productive for snakehead and featherback during the early cool season when fish that have dispersed through the monsoon rains begin to consolidate around structure. The deeper central sections are where catfish concentrate during the heat of the day. Shallow bays with emergent or floating vegetation are dawn-and-dusk territory for snakehead working the surface.
Understanding how the reservoir changes with water level is important. When levels are high after the rains, fish spread into new areas including seasonally flooded vegetation that only exists for a few weeks. When levels drop through the dry season, fish concentrate into the main basin and the permanent arms, making them more predictable but also more localised.
Seasons and Strategy
The best time to fish in Thailand broadly applies to Sirikit: the cool season from November through February is the peak window. Temperature, water clarity, and fish behaviour all align in the angler's favour during these months.
The monsoon period from June through October is not without opportunity — snakehead fishing can be excellent during the early monsoon when warm rain and rising water trigger feeding activity — but conditions are less predictable and the experience less comfortable. Heavy rain can make boat fishing difficult, and rapidly changing water levels complicate location.
March through May heats up steadily. Fishing shifts toward early morning sessions beginning before first light and winding down by mid-morning. Evening sessions from late afternoon into dusk can also produce, particularly for featherback which are notoriously nocturnal. Midday fishing in April is an exercise in persistence rather than productivity.
Access and Transport
Uttaradit is the gateway city. From Bangkok, the northern train line provides a practical and reasonably comfortable option — the overnight train from Hua Lamphong reaches Uttaradit in around seven to eight hours, arriving in the morning in time to organise the day. Flying to Phitsanulok and driving north is faster, adding an approximate two-hour drive to reach Uttaradit and then onward to the reservoir.
From Uttaradit town, the reservoir access varies by which section you intend to fish. The dam area and nearby visitor facilities are the most accessible. More productive fishing areas deeper in the reservoir arms require local transport — typically via a guide who knows the appropriate access roads and can confirm current conditions. Road infrastructure in the area is functional but rural, and some access tracks are only suitable for high-clearance vehicles.
Anglers connecting from Chiang Mai, approximately four hours southwest, will find that combination of a northern base and a reservoir trip makes logistical sense. See our Chiang Mai fishing guide for orientation.
Sirikit Reservoir sits within a region where some access roads become impassable during heavy monsoon rains. If planning a trip between July and September, confirm road conditions with your guide before committing to an itinerary.
Where to Stay
Uttaradit town provides the most reliable accommodation with reasonable variety across price points. The town is not a major tourist destination, which keeps prices modest and crowds manageable. Local guesthouses and smaller hotels offer comfortable, practical bases for multi-day fishing trips.
Closer to the reservoir, a handful of guesthouses and bungalow-style accommodation caters primarily to domestic visitors and occasional fishing groups. These are simple by any standard — basic facilities, limited English, and variable food options — but they put you close to the water for early starts. Verify current availability before assuming these options exist; small guesthouses in rural areas open and close without fanfare.
On Conservation
The Nan River catchment, which feeds Sirikit, is part of a broader system that faces deforestation and agricultural pressures in its upper reaches. The reservoir's water quality is a downstream indicator of watershed health, and what happens in the hills above the dam matters to the fish below it.
Catch-and-release fishing is the appropriate ethic for all large predators here. Giant snakehead, featherback, and large catfish are slow-growing fish that have reached their size through years of survival. Removing them from the system diminishes something that took decades to build. Our article on catch-and-release rules in Thailand covers best practices for releasing fish in warm-water environments.
Sirikit's relative obscurity is part of what makes it worth protecting. Wild fishing comparisons often overlook the role of pressure in determining fish quality — and a lesser-pressured reservoir tends to produce better fish. Treat Sirikit quietly and it will reward future visits accordingly. Compare the experience to more managed venues in our overview of wild Thailand versus pay lakes.
The reservoir asks little of visiting anglers beyond preparation and respect. In return, it offers quiet water, wild fish, and the particular satisfaction of catching something in a place that has not been optimised for your convenience.
