Before buying a home in Xizhi, check three things first: the flood potential and recent flood records for the exact building you want, the actual services and fares of your commute, and where the transaction price and building age sit within the district. Flooding on the Keelung River recurred between 1998 and 2001; the Yuanshanzi flood diversion project was completed on October 28, 2005, and the official diversion record had accumulated 66 diversions by June 26, 2026; the purpose of a flood diversion facility is to lower water levels and reduce flood risk, and it must not be treated as a guarantee that a place "will not flood". House prices and building ages use the medians from this site's compilation of four quarters of actual-price registration data (transaction dates mainly span late 2019 to July 2026): in Xizhi District the median transaction unit price is NT$437,000 per ping (1 ping ≈ 3.3 m²) and the median building age at transaction is 29 years; this article makes no price prediction of any kind.
Scope note: The flood and diversion data come from the tenth river branch office of the Water Resources Agency, Ministry of Economic Affairs (經濟部水利署第十河川分署), the disaster potential explanations come from the national disaster reduction science and technology center (國家災害防救科技中心), the metro progress comes from the New Taipei metro construction bureau (新北市捷運工程局), and the actual-price registration data is this site's compilation of Ministry of the Interior data (downloaded 2026-11-05). All of these data carry update dates, which are marked item by item in the text; before buying, rely on each agency's current page.
Flood history: how the official chronology puts it
The "governance chronology" page of the tenth river branch office (published 2023-11-23) lists, as a timeline, the origin of the Keelung River and Yuanshanzi flood diversion plan; the milestones directly related to Xizhi are the following:
| Date | What the official page records |
|---|
| 1998-10-13 | Typhoons 瑞伯、芭比絲 caused serious flooding in the Xizhi and Wudu areas, and the water authorities began a "feasibility review of the Keelung River Yuanshanzi flood diversion plan" |
| 2000-10-31 | Typhoon 象神: the flooded area was about 465 hectares, including townships such as Ruifang and Xizhi in Taipei County (臺北縣); the page says it caused 59 deaths |
| 2001-05-11 | The Executive Yuan approved the Yuanshanzi flood diversion project within the overall Keelung River governance plan, with an implementation budget of about NT$6 billion (60 in units of NT$100 million) |
| 2001-09-16 | Typhoon 納莉: the page describes it as the worst flood on the Keelung River in its history, with the flooded area including townships such as Pingxi, Ruifang and Xizhi in Taipei County, causing 104 deaths |
| 2002-06-05 | Main construction of the Yuanshanzi flood diversion began (the facility page says it began on June 5, 2002) |
| 2003-12-01 | The Yuanshanzi flood diversion tunnel broke through |
| 2004-09-11 | The 1st activation of Keelung River Yuanshanzi flood diversion (note on the diversion data page: the works were not complete, calculated from the water depth observed at the weir sill) |
| 2005-10-28 | The Yuanshanzi flood diversion project was fully completed |
This table lists only the major events the official page gives. The extent and causes of each flood in Xizhi after 2005 were not obtained from official event-by-event statistics for this article, and it does not speculate; the later section on using the disaster potential map explains how to look up recent flood locations yourself.
What the Yuanshanzi flood diversion channel does, and what it cannot be taken to mean
The "Yuanshanzi flood diversion channel" page of the tenth river branch office (published 2025-01-22) explains that the main stem of the Keelung River is 86.4 km long, flows through the heavily developed Taipei Basin in its middle and lower reaches, and has a narrow channel with limited flood storage space, so low-lying areas flood easily; after evaluation, the Yuanshanzi flood diversion project was judged to have the most concrete effect. Some official figures:
| Item | What the official page says |
|---|
| Diversion principle | For an upstream 200-year return period flood volume of 1,620 cms, 1,310 cms is diverted to the East China Sea, keeping a base flow of 310 cms in the downstream river, with the aim of lowering water volume and levels in the middle and lower reaches and reducing flood risk |
| Tunnel | About 2.48 km long, 12 m in diameter |
| Main works | Began on June 5, 2002 and completed on October 28, 2005 |
| Expected benefit | Discharging 1,310 cms (81%) of an upstream 200-year-frequency flood volume to the East China Sea, which can lower the water level at the Ruifang reach by 3.13 m and the average water level in the downstream reach by 1.5 m |
| How it is activated | Automatic diversion by natural overflow; when the water level in front of the weir reaches EL63.0 m, the sediment-flushing gate is closed and diversion begins |
The "Yuanshanzi diversion information" page on the same website (published 2026-07-07) has a diversion record event by event: from September 11, 2004 to the "0624 heavy rain event" (0624 豪雨) on June 26, 2026, which was the 66th. The largest single diversion by volume was the 1019 heavy rain event (1019 豪雨) from October 20 to 22, 2025, when diversion lasted 63 hours 26 minutes with a volume of about 28,965,000 cubic meters (2896.5 ten-thousand cubic meters); the highest recorded diversion water level was in 2015 during a typhoon (杜鵑颱風) at 66.02 m, and the heavy rain of September 22, 2024 at 65.76 m was the second highest.
These points need to be read together:
- This article's reading: many diversions mean that water levels in the upper Keelung River still repeatedly reach the activation level and the facility is working; this is not itself a record of flooding in Xizhi, nor proof that it does not flood.
- The official design principle is aimed at "an upstream 200-year return period flood volume", and the page's wording is "reduce flood risk". Inferring from this (this article's reading; the page does not say so), rainfall beyond the design conditions is outside the design range.
- Flooding does not come only from rivers. The explanation of the national disaster reduction science and technology center says that when short, heavy rainfall or long accumulated rainfall cannot be drained in time, water floods the area; excessive river or stream flow causing levee breaks or overflows also floods nearby areas. So a place far from the river can still flood from low-lying ground or inadequate drainage.
Therefore, treating "there is already a diversion channel" as a reason for not flooding does not match what the official data says.
Check the place you want to buy with the disaster potential map
The 3D disaster potential map of the national disaster reduction science and technology center defines "disaster potential" as a place where a disaster occurred in the past or where there is a higher chance of disaster in future. The main points of the flood potential explanation:
- The nationwide flood layer comes from the third-generation flood potential map made by the Water Resources Agency, produced in 2014 to 2016, on the basic assumption of fixed rainfall over 6, 12 and 24 hours and the largest flood depth that could occur in each area.
- 300mm, 450mm and 600mm stand for accumulated rainfall within 24 hours; the more rain, the larger the simulated flooded area and depth.
- The site also has a "flood survey locations of the past five years" layer, covering important flood events from 2021 to 2025, with records sourced from Water Resources Agency reports during floods and post-flood special surveys, reports from the Central Disaster Response Center, and field visits by academic teams and the national disaster reduction science and technology center.
- The explanation page also notes that flooding and ponding are separated at 50 cm: only when the home people actually live in is flooded to 50 cm or more by a flood is it called flooding, and below that it is called ponding.
Suggested way to look: open the map, enter the address you want to buy, look separately at the three scenarios of 300, 450 and 600 mm in 24 hours, then switch on the "flood survey locations of the past five years" layer and check whether the surrounding streets have records. The potential map is a simulation and the five-year survey is actual records, so look at both together. For real-time disaster information, see this site's New Taipei real-time disaster map. Residents of low floors should pay particular attention to drainage and check valves; see low-floor drainage backflow check.
Commuting: Taiwan Railway today and the metro under planning
Taiwan Railway from Xizhi, Xike and Wudu to Taipei
The table below is the result of the Taiwan Railway website lookup for services leaving for Taipei between 7:00 a.m. and 9:00 a.m. on Monday, 2026-11-09 (verified 2026-11-07):
| Origin station | Train type | Full fare | Travel time listed on the official website |
|---|
| Xizhi (汐止) | Local, local express | NT$33 | Local 20 to 26 minutes; local express 21 minutes |
| Xizhi (汐止) | Tze-Chiang limited express | NT$52 | 20 minutes |
| Xike (汐科) | Local, local express | NT$30 | Local 17 to 23 minutes; local express 18 minutes |
| Wudu (五堵) | Local | NT$36 | 23 to 29 minutes |
The table takes only the services in the official lookup results that are not marked as suspended; the same lookup also lists services marked "suspended on the whole section" or "partly suspended", and these are not included in the table (they are mostly local express, so the local express time in the table therefore corresponds to a single service); rely on the Taiwan Railway timetable before you travel. Xike and Wudu have fewer services than Xizhi; in the lookup results Xike has no Tze-Chiang service, and Wudu has no local express or Tze-Chiang service. Whether there is a service at the time you need to be at work, use the Taiwan Railway timetable for your actual departure time. For a comparison of Taiwan Railway and freeway commuting from Keelung to Taipei, see this site's Keelung to Taipei commute summary; this article did not check traffic on National Freeway 1 and 3 or coach services, so rely on the freeway bureau (高公局) and each coach operator's website.
Metro lines under planning and construction (per the New Taipei metro construction bureau route pages, 2026-11-07)
| Item | Xidong Line (Xizhi–Donghu Line, 汐東線) | Keelung MRT |
|---|
| Line scale | 5.56 km in total with 6 stations; 4.75 km in New Taipei and 0.81 km in Taipei | The page says 15.6 km |
| Expected completion | The page marks expected completion in year 121 of the Republic of China calendar, that is 2032 | The page marks expected completion in year 122 of the Republic of China calendar, that is 2033 |
| Budget | The page header gives a revised budget of NT$62.106 billion (621.06 in units of NT$100 million), while the budget field in the body says NT$37.693 billion (376.93 in units of NT$100 million), and both figures are on the same page; the same page says the revised plan is still being processed and was submitted to the Ministry of Transportation and Communications for review for the 3rd time on July 2, 2026, so the NT$62.106 billion (621.06) is the figure of the revised proposal under review | NT$69.689 billion (696.89 in units of NT$100 million) |
| Progress | The design-build contract was awarded on 2024-10-22 and construction began on 2025-03-20; a press release of 2025-09-04 says the first full-casing pile was started, aiming at a 2032 completion target | On 2024-01-31 the Executive Yuan approved the comprehensive planning report of the "Keelung–Nangang commuter rail construction plan" (基隆南港間通勤軌道建設計畫); preliminary works began on 2025-12-30, in the area around station SB19 (百福公園); the environmental impact assessment for the Badu depot received the review opinions of the Ministry of Transportation and Communications by letter on 2026-10-13 |
| Transfer to Taiwan Railway | The line runs along Datong Road Section 1 and transfers with Taiwan Railway's Xike station at station SB14 | Promoted as part of the same network as the Xidong metro |
These are all "expected" and "target" dates as written on the construction bureau pages, not opening dates. The official press release also says that after the Xidong Line opens, the peak commuting time from Xizhi to Taipei's urban area can be cut by half an hour; this is the expectation of the New Taipei metro bureau, not a result that has happened. The Keelung MRT schedule matches the "around 2033" given in this site's Keelung to Taipei commute summary; the progress of the Taipei City section of the Minsheng–Xizhi Line (民生汐止線) was not checked in this article.
House prices and building age: this site's four-quarter compilation of actual-price data
The figures below come from this site's compilation of the four quarters 114S4 to 115S3 of the Ministry of the Interior's real estate transaction price registration data (actual-price registration), calculated as a combined total and downloaded on 2026-11-05. It is a four-quarter combined statistic, not a single quarter; transaction dates fall mainly between 2019-11-27 and 2026-07-21, so these are not only transactions from the most recent year.
| Item | Xizhi District |
|---|
| Median transaction unit price | NT$437,000 per ping |
| Unit price, 25th percentile to 75th percentile | NT$359,000 to NT$552,000 per ping |
| Unit price sample size | 1,224 records |
| Median building age at transaction | 29 years |
| Building age sample size | 1,351 records |
| Building age distribution (records) | Under 5 years 116; 5 to under 15 years 168; 15 to under 30 years 475; 30 years or more 592 |
How to read this table: the median is the transaction in the middle once unit prices are sorted; it is not an "average" and not the price of your property; unit prices are strongly affected by building age, floor, whether a parking space is included and similar factors. This compilation takes only residential apartment, mid-rise, high-rise residential, studio and townhouse transactions of land and buildings together, and excludes transactions whose remarks include words such as relatives or friends, employees, co-owners or special relationships; for transactions with a parking space but a parking space total price of 0, the unit price includes the parking space and cannot be separated, so they are not counted in the unit price statistics (they are still counted in the building age statistics). Building age is the transaction year minus the year of building completion, and only 0 to 80 years is used.
By building age distribution, transactions of buildings 5 years or older make up about 91% (116 records, about 9%, are under 5 years), and buildings 30 years or older number 592, about 44% of the 1,351. This is a statistical description; it does not represent the condition of any single building and is not a judgment about future prices. To work out building age you can use the building age calculator.
Checklist for buying an older home
- Check flooding first: use the potential map and the five-year flood survey locations above to confirm the surroundings, then look in person at the ground floor, basement and driveway for water marks, wall efflorescence and peeling (壁癌, literally "wall cancer") or pumping equipment, and ask residents about conditions during heavy rain in recent years.
- Confirm building age and use permit: check the date the use permit was issued and the building completion date registered on the transcript; for the method see how to check building age and use permit date.
- Apply for transcripts: land and building transcripts can be applied for online; for the steps see online application for land and building transcripts, to check the owner, mortgages and registered restrictions.
- Compare transaction records: look up transactions in the same community with similar building age and floor in the actual-price registration, and do not rely only on the district-level medians in this article.
- Inspect the home: have professionals check leaks, piping and wiring and the structure; this site also has a home inspection checklist you can use for a first look yourself.
- Test the commute: travel the route once at the hours you would actually work, trying Taiwan Railway, a scooter and buses.
FAQ
After the Yuanshanzi flood diversion channel was completed, will Xizhi still flood?
The official data says the purpose of the diversion facility is to lower middle and lower reach water levels and reduce flood risk, and it was designed for an upstream 200-year return period flood volume; the diversion record had accumulated 66 diversions by 2026-06-26, which means upstream water levels still repeatedly reach the diversion condition. Flooding can also come from short, heavy rainfall that cannot be drained in time, so look up the potential and recent flood surveys for the address you want to buy; this article does not say "it no longer floods".
When will the metro in Xizhi open?
According to the New Taipei metro construction bureau route pages of 2026-11-07, the Xidong Line is marked with expected completion in year 121 (2032) and the Keelung MRT in year 122 (2033); these are expectations, not confirmed opening dates. When buying a home, evaluate it on the existing Taiwan Railway commuting conditions.
Can the actual-price median be used directly to make an offer?
It is not recommended. This article cites the four-quarter combined median for the whole of Xizhi District, and unit prices are related to building age, floor, parking space and community. To make an offer, look at recent transactions in the same community and the conditions of the property you want to buy.
Is this four-quarter data a single quarter?
No. This site's compilation is the combined statistic of the four quarters 114S4 to 115S3, downloaded on 2026-11-05.
Sources
- Tenth river branch office, Water Resources Agency, Ministry of Economic Affairs (經濟部水利署第十河川分署): governance chronology (verified 2026-11-07): timeline of the 1998, 2000 and 2001 floods and the Yuanshanzi flood diversion plan; page published 2023-11-23.
- Tenth river branch office, Water Resources Agency, Ministry of Economic Affairs (經濟部水利署第十河川分署): Yuanshanzi flood diversion channel (verified 2026-11-07): diversion principle, tunnel specifications, construction period and benefits; page published 2025-01-22.
- Tenth river branch office, Water Resources Agency, Ministry of Economic Affairs (經濟部水利署第十河川分署): Yuanshanzi diversion information (verified 2026-11-07): event-by-event diversion record up to the 66th; page published 2026-07-07.
- National disaster reduction science and technology center (國家災害防救科技中心) 3D disaster potential map home page (verified 2026-11-07): the definition of "disaster potential".
- National disaster reduction science and technology center (國家災害防救科技中心) 3D disaster potential map: where floods occur easily (verified 2026-11-07): simulation conditions for flood potential, the five-year flood survey locations layer, and the definitions of flooding and ponding.
- New Taipei metro construction bureau (新北市政府捷運工程局): Xidong MRT (verified 2026-11-07): line scale, expected completion year, budget and construction start dates.
- New Taipei metro construction bureau (新北市政府捷運工程局): Keelung MRT (verified 2026-11-07): expected completion year, length, budget and records of approval and construction start.
- New Taipei metro construction bureau (新北市政府捷運工程局) press release: first pile started on the Xidong MRT (2025-09-04; verified 2026-11-07): the 2032 completion target for the Xidong Line and the commuting time expectation.
- Taiwan Railway: timetable and fare lookup (verified 2026-11-07): fares and running times from Xizhi, Xike and Wudu to Taipei between 7:00 and 9:00 a.m. on 2026-11-09.
- Ministry of the Interior real estate transaction price registration: data supply system (downloaded and compiled by this site on 2026-11-05; this site's compiled file verified 2026-11-07): this site's four-quarter combined statistics of unit price and building age medians for 114S4 to 115S3.
Related reading: Taipei and New Taipei Flood Potential Map & Home Buying
