• The irrigation water sources are all river-based.
• The operational area covers 14,318 hectares.

• Each local canal diverts water from Beinan River, Lijia River, Zhiben River, Taimali River, Luliao River, Mawu River, Jellyfish River etc. as a main water sources, and the rest divert water from small valley rivers and springs as supplementary water sources.
• Beinanshang Canal irrigation area uses water from Luye River, a tributary of Beinan River for irrigation.

The operational area of the office is located in the eastern part of Taiwan, starting from Dawu Township in the south, Changbin and Chishang Townships in the north, the Pacific Ocean in the east and the Central Mountains in the west, with the Coastal Mountains and Beinan Valley running through it. The administrative districts include Chishang, Haiduan, Guanshan, Luye, Yanping, Beinan, Taimali, Dawu, Taitung, Donghe, Chenggong and Changbin, totaling 12 townships, towns and cities, with an operational area of 14,318 hectares.

The dry season lasts from November to April of the following year. The wet season occurs in summer, characterized by monsoon rains and typhoons. Annual rainfall ranges from 2,000 to 2,400 millimeters, with most precipitation concentrated in July, August, and September. This uneven distribution means that the first crop cycle of each year falls during the dry season. While most irrigation systems implement rotational watering schedules, the Chenggong area lacks surface water sources, making rotational irrigation impossible there.

There are 181 primary, secondary, and ordinary rivers, all drawing surface water from rivers. Additionally, there are 8 drought-relief groundwater pumping stations, with a total extraction volume of 0.395 C.M.S.

Currently, there are 125 monitoring points checking the quality of irrigation water, along with 22 non-agricultural users discharging wastewater (including 8 authorized ones). Since there are no industrial factories in the area and only livestock farming, the water quality is generally good, with most tests meeting the required standards. Water quality is regularly monitored, with both initial and follow-up inspections conducted every two months. Re-test samples are sent to the Changhua Irrigation Association’s lab for analysis, and all test data is recorded and uploaded by designated staff.

The main crop in the jurisdiction is rice. There are 12 irrigation water quality monitoring points set at major irrigation and drainage intake points, branch lines, and the ends of waterways, determined based on the significance of water quality impacts.

1. Currently, there are 22 non-agricultural users in the area discharging wastewater, totaling about 1,598.95 tons per day. Of these, 8 authorized users release around 516.95 tons daily.
2. Since the region is large and not heavily populated, livestock discharge users have installed sewage treatment systems and large (fish) ponds to help dilute the wastewater and prevent serious pollution issues.

"Electrical Conductivity" (EC) measures the amount of soluble salt in water. The higher the salt content, the better the water conducts electricity. Conductivity and water resistance are inversely related—when resistance increases, conductivity decreases. For irrigation water, an EC value above 750 µmhos/cm reaches the standard limit for water quality. If it exceeds 1,250 µmhos/cm, it represents the highest level rice can tolerate before it begins to affect crop yields, especially in low-lying, poorly drained fields with heavy clay soil.

The concentration of hydrogen ions in water is often represented by the pH value, which indicates the acidity or alkalinity of the solution. A pH value above 7.0 is considered alkaline, while a value below 7.0 is considered acidic. For irrigation water quality, the acceptable pH range is between 6.0 and 9.0.

In artificial irrigation, a system is established to ensure that water is delivered in a "timely," "adequate," "methodical," and "orderly" manner. This approach is designed to meet the changing water needs of different soils and crops throughout their growth stages, helping to boost agricultural productivity. By following a strict, organized schedule that rotates across zones and plots, this fair and efficient method is referred to as "rotational irrigation."

The jurisdiction is located in southeastern Taiwan, experiencing dry northeastern monsoons in winter and hot tropical maritime climates with southeastern winds in summer. From November to May each year, the area faces a dry season, necessitating drought relief measures. During the rainy season, characterized by plum rains and typhoons, water is abundant. Consequently, the first cropping period each year falls in the dry season, when rivers in the jurisdiction have low water levels, requiring rotational irrigation or drought relief strategies. The office has established the "Taitung Irrigation Association Drought Response Measures for Irrigation Systems at Various Levels of Drought Severity," along with a drought response team (activated when the water deficit exceeds 40%) and a Taitung County Drought Coordination Team (formed when the water deficit exceeds 50%).

According to the office's drought response measures for irrigation systems at various levels of drought severity, actions include pumping groundwater to supplement irrigation and advising farmers in water-deficient areas to fallow their land or temporarily suspend irrigation. Riverbed water diversion structures are reinforced with water-retaining facilities or covered with plastic sheeting to prevent leakage. During drought periods, employees' leave is suspended, and all staff, along with irrigation group and irrigation unit leaders, are mobilized for drought relief efforts.

In artificial irrigation, a system known as "rotational irrigation" has been established to maintain a timely, adequate, methodical, and orderly approach to water distribution. This system aims to achieve scientific irrigation management by supplying water according to the needs of different soils and crops during their various physiological stages, thus increasing agricultural production. It operates in a structured manner, following a regulated sequence within each rotational zone and the plots within it. This process ensures a fair and rational distribution of water, cycling through the irrigation network in an orderly fashion.

• Timely
  Water is supplied during periods when crops require it, promoting increased yield.
• Adequate
  Water is provided in the necessary amounts during different growth stages to ensure healthy development, avoiding waste and increasing the irrigation area and productivity.
• Methodical
  Each crop's water requirements, irrigation timing, farming seasons, available water sources, and climatic conditions are thoroughly studied before irrigation begins. An irrigation plan is established before implementation, following the principle of public management of private farmlands. This approach aims to increase production while achieving economic efficiency.
• Orderly
  Irrigation schedules and sequences are established to ensure that upstream users do not take more than their share, while downstream users receive their fair portion. This fosters local harmony and cooperation, helping to maximize agricultural output for the nation.

All irrigation water sources in this jurisdiction derive from surface river water. The absence of reservoirs or ponds for water storage results in a highly unstable water supply. The first cropping period each year coincides with the dry season, necessitating rotational irrigation to ensure adequate water for irrigation services. The second cropping period occurs during the typhoon-prone rainy season, requiring diligent typhoon prevention measures and the maintenance of temporary water diversion structures to secure sufficient irrigation water for crop needs.

This jurisdiction relies exclusively on river water, a source that is both difficult to access and unstable. When constructing temporary water diversion structures, it is imperative to impound sufficient water in a single operation, with any excess subsequently discharged through designated drainage channels.

The irrigation plan is formulated based on the water requirements of rice fields during land preparation and various stages of crop growth, with adjustments made according to available water sources. One month prior to each cropping period, irrigation plans are devised for both rice and dry crops. These plans for each irrigation channel are then inputted into a computer system and subsequently printed for distribution.

Due to differences in water sources and regions, irrigation execution is divided into two areas: the coastal mountain range water sources in the Chenggong area (including the Donghe, Chenggong, and Changbin stations) and the Taitung area, which relies on the Beinan River and other water sources from the Lijia, Zhiben, and Taimali Rivers (including the Taitung, Beinan, Zhiben, Luye, Guanshan, and Chishang stations).

• Chenggong Area
  Due to scattered farmland and simple irrigation systems, rotational irrigation cannot be implemented, and irrigation is executed by local pond managers.
• Taitung Area
  Irrigation execution is managed by station staff responsible for different sections. The staff is in charge of regulating water distribution from main lines, lateral canals, and sub-lateral canals. When water supply is sufficient, continuous irrigation is implemented. In case of water shortages, large-area rotational irrigation is conducted based on lateral and sub-lateral canal divisions. During severe shortages, management personnel must suspend their leave to implement emergency irrigation protocols. Local water controllers are also hired to assist in executing these emergency irrigation measures.

Within the jurisdiction of the office, with the exception of the 7-17 Lateral Canals of Guanshan Canal which are a post-single cropping field and Taoyuan Canal, Luye Canal, and Beinanshang Canal which employ dry farming irrigation, the remaining canal areas are three cropping agricultural fields.