Water Resources Planning Branch, WRA, MOEA

I. Regulation Planning of Major and Minor Rivers in Taiwan

In October 1967, the River Governance Planning Corps was established (the predecessor of the Water Resources Planning Branch).
Governance began with comprehensive river planning—including flood confinement, flood guidance, flood storage, flood diversion, and flood avoidance—to formulate river governance plans that would be implemented after review and public announcement.
These plans provided key foundations for flood-control works under the Twelve/Fourteen Major Economic Construction Projects and the Six-Year National Construction Program.

Launched 2004–2008 in line with the national policy “Challenge 2008—Ecological River Management and Waterfront Amenities.”
Objectives: build fundamental river datasets, improve river environments, maintain normal river functions, create nature-rich waterside spaces and recreation, and enhance biodiversity to achieve disaster-mitigation goals and a healthy river environment.
Phase II (2009–2014) continued these efforts, aligned with the “2015 Economic Development Vision” toward a prosperous, just, and sustainable living environment.

The Keelung River, a major tributary of the Tamsui River, meanders through valleys with narrow, low-lying plains. Proximity to the Taipei metro area led to intensive development on both banks, causing severe land-water conflicts.
Orographic effects produce two heavy-rain centers—Huoshaoliao in the upper basin and Yangmingshan downstream—making typhoon-induced cloudbursts and flash floods common, with Xizhi and Wudu particularly hard-hit.
In November 2000, WRA proposed the Yoanshanzi Flood Diversion project to reduce downstream flows via diversion. However, by itself it could not achieve protection at the 200-year return-period peak flow.
Therefore, the Integrated Regulation Plan of the Keelung River was developed and approved by the Executive Yuan in May 2001; implementation followed (see Fig. 1).
Early works were completed by end-March 2002, but provided only 10-year return-period protection due to highly developed banks, constrained channel, and limited flood storage.
Under the premise of advancing the Yoanshanzi diversion, the plan (approved April 2002) set out measures to address flooding:
- Structural: flood protection or storage, diversion, conveyance enhancement, detention, tributary interception, and channel dredging.
- Non-structural: flood insurance for low-lying areas, land-use planning for flood-prone zones, and delineation/regulation of floodplains (see Photos 1 and 2).

To resolve inundation in subsidence zones, low-lying areas, and urban districts and safeguard households and the economy, the Ministry of Economic Affairs in 2005 proposed a county/city-scale, systemwide approach (rivers under local jurisdiction, regional drainage, and industrial seawalls), modeled on the Keelung River experience; it received the Executive Yuan’s in-principle consent.
From 2006 to 2013), planning works were completed for: Dezihkou River, Nankan River, Yuanli River, Linbian River, Taimali River, Zhiben River, Lijia River, and Meilun River.

Planned period: 2021–2026.
Uses climate-change risk scenarios as stress tests for basin flood-protection capacity, identifying high/medium/low-risk areas and introducing risk-management concepts with adaptation measures.
Also emphasizes habitat conservation, waterfront landscape, water culture and history, and natural landscape creation to enhance waterfront environmental quality.
Vision: build flood resilience and a vibrant aqueous environment.

Fig. 1 Flood-diversion route alignment in the 2002 engineering design.

Photo 1. Pre-construction photograph of the Yuanshanzi Flood Diversion on the Keelung River.

Photo 2. Post-construction photograph of the Yuanshanzi Flood Diversion on the Keelung River.