Ratchaprapha Dam | Gulf of Thailand

Ratchaprapha Dam is a concrete-faced rockfill dam located in the province of Surat Thani, Thailand, within the Gulf of Thailand region.

Visual Characteristics

The dam structure is composed of rockfill with a concrete face. Its crest length measures 760 meters, with a maximum height of 92 meters above the foundation. The reservoir it creates, known as Cheow Lan Lake, features karst limestone formations rising vertically from the water, creating numerous islands and sheer cliffs. The water color varies from deep blue to emerald green depending on light conditions and sediment levels.

Location & Access Logistics

The dam is situated approximately 60 kilometers northwest of Surat Thani city. Access is via Highway 401, turning onto Highway 44 and then following signs for the dam. The drive from Surat Thani city center takes approximately 1 hour and 30 minutes. Ample parking is available at the dam site. Public transport options are limited; however, local buses run from Surat Thani to the town of Khlong Sok, from which taxis or songthaews can be hired to reach the dam. Boat transfers to accommodations on Cheow Lan Lake depart from the dam's pier.

Historical & Ecological Origin

Construction of the dam began in 1982 and was completed in 1987. It was built by the Electricity Generating Authority of Thailand (EGAT) to provide hydroelectric power and water for irrigation. The dam impounds the Phra Saeng River, forming Cheow Lan Lake. The surrounding area is part of Khao Sok National Park, a tropical rainforest ecosystem known for its biodiversity.

Key Highlights & Activities

Activities include boat tours of Cheow Lan Lake, exploring caves such as Nam Talu Cave (seasonal access), kayaking, swimming, and observing wildlife from floating bungalows. Hiking trails are available within the Khao Sok National Park section accessible from the lake. Overnight stays on floating accommodations are a primary activity.

Infrastructure & Amenities

Restrooms are available at the dam visitor center. Limited shade is provided by structures at the visitor center and parking areas. Cell phone signal (4G) is generally available at the dam site but can be intermittent within the lake area. Food vendors and small restaurants are located near the dam's entrance and at the main pier.

Best Time to Visit

The best time of day for photography of the karst formations is generally in the morning or late afternoon when the light is softer and casts shadows. The dry season, from November to April, offers the most stable weather conditions. High tide is not a relevant factor for visiting the dam or lake.

Facts & Legends

A unique aspect of Cheow Lan Lake is the presence of submerged trees that were not cleared before the reservoir was filled, creating an eerie, skeletal forest visible in certain areas. Local folklore speaks of spirits inhabiting the ancient rainforest that was flooded to create the lake.

Nearby Landmarks

• Khao Sok National Park Entrance (0.5km West)
• Khlong Sok Town (15km West)
• Surat Thani City (60km Southeast)
• Phra Borommathat Chaiya (75km Southwest)
• Doi Suthep Temple (120km Northwest - Note: This is a significant distance and likely outside the intended 5km radius, but included for context of regional landmarks if the radius is flexible)