Assessing Your Flood Risk

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In 1998, San Antonio suffered a 1-Percent Annual Chance Flood Event (also known as a 100-year flood).

In 1998, San Antonio suffered a 1-Percent Annual Chance Flood Event (also known as a 100-year flood). Photo credit: San Antonio Express-News

The San Antonio River Basin has a long history of flooding that has shaped how communities prepare for future flood events. Whether you live in a floodplain or not, it’s important for everyone to learn about how to assess their flood risk and what tools are available to make the best decisions to protect their property and life.

Read along as we share more info about flooding and how you can best assess your own flood risk.

Why does it flood in our area?

In 1946, the San Antonio River and area creeks flood resulting in catastrophic damage.

In the San Antonio River Basin, particularly in Bexar County, steep terrain, shallow soils, and narrow creek and river channels send runoff quickly downhill. The result is deep, fast, and erosive flood waters. This area is part of a region known as Flash Flood Alley. These destructive forces have the potential to penetrate communities downstream, threatening lives and property throughout the basin.

 

How does the River Authority address flooding in our area? 

The River Authority uses comprehensive planning, precision protection, strategic partnership, and community preparedness to help communities throughout the San Antonio River Basin reduce the devastating effects of flooding.

As a Cooperating Technical Partner with the Federal Emergency Management Agency (FEMA), the River Authority also works with local communities and FEMA to implement programs and projects to incorporate local knowledge and data into flood hazard mapping and mitigation planning. The goal of the River Authority is to reach a sensible balance between physical, chemical, biological, and economic factors while still maintaining the integrity of the watersheds throughout the San Antonio River Basin.

How can I assess my own flood risk?

The River Authority has invested considerable resources in developing updated floodplain maps throughout Bexar, Wilson, Karnes, and Goliad counties. This investment combined with our expertise has produced some of the highest quality floodplain maps in the country. Visit our website to assess your home’s flood risk by looking at the River Authority Floodplain Viewer and the Risk Map Viewer.

Screenshot of River Authority's Risk Map Viewer

The Floodplain Viewer will help you determine if your property is in the 1-percent annual chance floodplain. If your property is in the 1-percent annual chance floodplain (which is also referred to as the base flood or 100-year floodplain), you may be required to obtain flood insurance. The Risk Map tool can be utilized to help you assess your level of flood risk, including insights such as the level of risk over the life of a 30-year mortgage.

Should I get flood insurance?

Floods continue to be the most common and costly natural disaster in the United States. According to FEMA, there is some level of flood risk no matter where you live or work. In fact, about 25% of all flood insurance claims come from areas with minimal flood risk. Therefore, the River Authority supports FEMA’s recommendation for homeowners to participate in the National Flood Insurance Program.

 

Related Articles

Alerts

Stay Weather‑Aware This Weekend

Stay Weather‑Aware This Weekend

Rain is expected across the region this weekend, which may result in high water on roads and temporary closures at low water crossings.

Before heading out, residents are encouraged to check SARiverFlood.org or their local county flood website for real‑time roadway conditions:

These sites provide up‑to‑date information from flood‑monitoring sensors across the region. Real‑time updates are available 24/7 to help you stay informed as conditions change.

Please use caution when traveling and plan routes accordingly.

Restroom Closure Notice – Camino Coahuilteca (Acequia Park Trail)

 

Restroom Closure Notice – Camino Coahuilteca (Acequia Park Trail)

The restrooms at Camino Coahuilteca along the Acequia Park Trail will be temporarily closed on Thursday, April 16 due to parking lot improvements in the area.

We encourage visitors to plan accordingly and utilize nearby facilities during this time.

We appreciate your patience as we complete this work to enhance the park experience.

 

Museum Reach – Oxbow Trail Closure Notice

The Oxbow Trail along the Museum Reach will be temporarily closed beginning Monday, April 13 through May 1 to accommodate project-related work in the area.

For public safety, access to this section of the trail will be restricted during this time. Visitors are encouraged to plan accordingly and use alternate routes.

Wayfinding signage and trail closure notices will be posted at designated locations to help guide trail users around the closure.

We appreciate your patience and understanding as we complete this work to help maintain safe and enjoyable trail conditions.

San Pedro Creek Culture Park

The east bank trail along San Pedro Creek will be temporarily closed between the upper trail at Cameron St. and the lower trail at two access points.

Closure details:

  • The first closure will impact the connector from the upper trail near West Houston St. to the south lower San Pedro Creek trail.
  • Once work at this location is complete and the trail reopens, construction will shift to the second closure area between the upper and lower trails on the opposite side of the green space.

Please follow posted signage and plan alternate routes. We appreciate your patience as this work is completed.

Closed areas around San Pedro Creek Culture Park

The Brackenridge Trail

Trail Lighting Notice – Brackenridge Park Trail

Due to an electrical issue, lighting is currently out along the north portion of the trail, from the Josephine Street inlet to just past Highway 281 within the Brackenridge Park Trail. Our team is actively working to correct the issue and expects repairs to be completed by the end of business tomorrow.

We apologize for any inconvenience this may cause and appreciate your patience as we work to restore lighting. Please use caution when traveling through this area, especially during evening hours.

Trail Closure Alert – Calder Alley, San Pedro Creek

Maintenance work will be done in Calder Alley starting Wednesday, September 18, 2025.

  • Trails will remain open during this work.
  • One bench at a time will be temporarily barricaded while improvements are completed.
  • There may be occasional contractor pickups in the area.

We appreciate your patience as we continue to maintain and improve San Pedro Creek for all to enjoy!

SASPAMCO Paddling Trail

The SASPAMCO paddling trail is open from River Crossing Park to Helton Nature Park.
*Please Note: Paddling Trail from Helton Nature Park to HWY 97 is still closed due to blockages. 

SASPAMCO Paddling Trail Temporarily Closed

Staff have removed two large log jams just downstream of Helton Nature Park, keeping the southern portion of the SASPAMCO Paddling Trail temporarily closed. Staff are working to contact adjacent landowners to support a land-based removal solution.

Goliad Paddling Trail Alert

NOTICE: HWY 59 Landing Site Closed

Due to TxDOT construction on the HWY 59 Bridge, the HWY 59 landing site is closed until further notice. However, the Goliad Paddling Trail remains open, and paddlers can still access the river at the Riverdale, Ferry Street, and Goliad State Park landings.

Please plan accordingly and check back for updates.

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