Effective storage
3,007.8 10k m³
▼ -7.1 10k m³ (vs Yesterday)Real-time conditions and historical storage trends
Observed at: 09/18/2026 12:00Daily operation date: 09/17/2026 00:00
Source: Water Resources Agency Reservoir Conditions and Daily Reservoir Operations datasets
Storage ratioOverflowing
100.5%
▼ -0.2% (vs Yesterday)— 0.0% (1 hr)
Effective storage: 3,007.8 10k m³ · Effective capacity: 2,993.4 10k m³
Real-time Hydraulic Briefing
Synthesized water storage and flow dynamicsCurrent water storage for 永和山水庫 is at 100.5% with a water level elevation of 85.05 m. Storage is down 0.2% compared to yesterday at the same time; outflow (2 m³/s) exceeds inflow (0.4 m³/s) during regulated release. Primary water supply covers Northern Miaoli County and Xiangshan District in Hsinchu.
永和山水庫 (ID: 10501) is an official Off-stream Reservoir situated in the Beikenggou, Zhonggang River System, operated and managed by Taiwan Water Corporation 3rd District Management Office. In operation since 1984, this facility serves as a vital strategic pillar in Taiwan's regional water grid and flood mitigation network.
According to the latest observation, its effective water storage is approximately 3,007.8 (10k m³), with a storage ratio of 100.5% and a real-time water level elevation of 85.05 meters. Hydraulic telemetry indicates an inflow of 0.4 m³/s and an outflow of 2 m³/s (net flow: -1.64 m³/s), actively conducting scheduled water supply and flood-control releases.
Primary functional purposes include Miaoli Municipal Water, Zhunan & Toufen Industrial Water, with key regional supply coverage extending across Northern Miaoli County and Xiangshan District in Hsinchu.
Primary Supply Area:Northern Miaoli County and Xiangshan District in Hsinchu
Miaoli Municipal WaterZhunan & Toufen Industrial Water
Water level
85.05 m
▼ -0.04 m (vs Yesterday)Inflow
0.36 m³/s
▲ +0.13 m³/s (1 hr)Total outflow
2 m³/s
▼ -0.02 m³/s (1 hr)Effective capacity
2,993.4 10k m³
Net Flow Balance
永和山水庫 · Real-time hydrological balance and storage dispatch analysis
Inflow (Qin)
0.36 m³/sUpstream catchment runoff inflow rateTotal outflow (Qout)
2 m³/sGate release and flood desilting rateNet Flow Balance (ΔQ)
-1.64 m³/sOutflow exceeds inflow during regulated discharge24 小時水文吞吐平衡走勢
雙向對稱流量觀測（上方為上游入流，下方為大壩放流，穿梭折線為淨出入差額）Discharge Gates & Facilities
Real-time telemetry for spillways, drainage tunnels, desilting tunnels, and power outlets.
Spillway outflowMain spillway gate release or crest free overflow
24h 待命常閉
Power outletHydroelectric turbine power generation discharge
24h 待命常閉
Desilting tunnelBottom desilting and sediment bypass tunnel
24h 待命常閉
Drainage tunnelDedicated flood diversion tunnel release
24h 待命常閉
Water drawMunicipal water, industrial, or irrigation draw
24h 待命常閉
Other outflowEcological baseflow or auxiliary facility release
2 m³/s
Historical Storage Trends
View historical storage percentage and water volume trends over time.
Reservoir Specifications · Geographic Location
永和山水庫 · Engineering profile and geospatial information
Managing AgencyTaiwan Water Corporation 3rd District Management Office
Facility TypeOff-stream Reservoir
River SystemBeikenggou, Zhonggang River System
Effective capacity2,993.4 10k m³
Year Completed1984
Geographic Location
24.6547°N, 120.9322°E苗栗縣 · 三灣鄉
Related Reservoirs in Region
Check real-time conditions and historical trends for other facilities in the same region.
Frequently Asked Questions
永和山水庫 · Key insights into reservoir metrics, release mechanisms, and facility operations
FAQ
Total capacity is the total physical volume of the reservoir basin.
In contrast, effective storage refers to the usable volume available for public, agricultural, or power supply above dead storage and sediment levels.