100-Year Storm Flood Risk Zone (July 2022)

This shapefile (polygon feature) contains the boundary of the July 1, 2022 100-Year Storm Flood Risk Zone, one of the layers of the July 1, 2022 100-Year Storm Flood Risk Map. Areas within this boundary are highly likely to experience “deep and contiguous” flooding during a 100-year storm. A 100-year storm is a storm that has a 1% chance of occurring in a given year. “Deep and contiguous flooding” means flooding at least 6-inches deep spanning an area at least the size of an average City block. The 100-Year Storm Flood Risk Zone does not provide the exact depth of flooding at a given location. It also does not show areas in the City that may experience shallower and/or more localized flooding in a 100-year storm. Finally, the 100-Year Storm Flood Risk Zone shows flood risk from storm runoff only. It does not consider flood risk in San Francisco from other causes such as shoreline overtopping and overland inundation from the San Francisco Bay or Pacific Ocean.

In addition to the 100-Year Storm Flood Risk Zone, the 100-Year Storm Flood Risk Map shows:

• “Areas not served by the Combined Sewer and Stormwater Collection System” - showing where data for rainfall driven storm runoff is not available, and where flood risk has not been analyzed.
• “Historical Shoreline”, “Historical Creeks”, and “Historical Waterbodies” - historical hydrology layers to illustrate the general topography of low-lying areas in the City.
The Horizontal Datum used for the GIS layers is “NAD_1983_2011_StatePlane_California_III_FIPS_0403_Ft_US.”

Notes on Usage

At a minimum, the 100-Year Storm Flood Risk Map is updated by the San Francisco Public Utilities Commission (SFPUC) on an annual basis on or before July 1 to account for any parcel review requests that remove properties from the Flood Zone. To confirm the latest version of the 100-Year Storm Flood Risk Map, check the SFPUC website at https://sfpuc.org/learning/emergency-preparedness/flood-maps to see if the map has been updated since the date of this shapefile or if there have been any parcel review determinations that identify parcels that are no longer part of the 100-Year Flood Risk Zone. The most recent official map, associated documentation, and list of parcels removed from the map from a parcel review process are available at https://sfpuc.org/learning/emergency-preparedness/flood-maps. Please be advised that the parcels listed are no longer considered to be within the 100-Year Flood Risk Zone as a result of the parcel review process. As of July 2022, this list is updated on an ongoing basis. Check the SFPUC website for any changes to this schedule.

The boundaries of this zone align with San Francisco parcel boundaries. The user should confirm proper projection or use of the webmap at https://sfpuc.org/learning/emergency-preparedness/flood-maps to properly identify parcels within the flood zone.

本矢量形状文件（多边形要素）包含了2022年7月1日百年一遇风暴洪水风险区的边界，该区域是2022年7月1日百年一遇风暴洪水风险图的一个图层。该边界内的区域在百年一遇风暴期间极有可能遭遇“深且连续”的洪水。所谓百年一遇风暴，是指在某一年内发生概率为1%的暴风雨。‘深且连续的洪水’是指深度至少为6英寸，覆盖面积至少相当于一个普通城市街区面积的洪水。百年一遇风暴洪水风险区不提供特定位置的洪水深度信息。它亦未展示在百年一遇风暴期间可能遭遇较浅或更为局部洪水的城市区域。最后，百年一遇风暴洪水风险区仅显示由风暴径流引起的洪水风险，不考虑如海堤溢出或旧金山湾或太平洋的陆上淹没等其他原因引起的洪水风险。

除了百年一遇风暴洪水风险区之外，百年一遇风暴洪水风险图还展示了以下内容：

• ‘未由合流污水和暴雨水收集系统服务的区域’——显示降雨驱动风暴径流数据不可用以及洪水风险未进行分析的区域。
• ‘历史海岸线’、‘历史溪流’和‘历史水体’——这些历史水文学层用以展示城市低洼地区的一般地形。
GIS图层所采用的水平基准为‘NAD_1983_2011_StatePlane_California_III_FIPS_0403_Ft_US’。

使用说明

至少每年一次，旧金山公共事业委员会（SFPUC）在7月1日或之前更新百年一遇风暴洪水风险图，以考虑任何将物业从洪水区移除的审查请求。为确保获取最新版本的百年一遇风暴洪水风险图，请访问SFPUC网站（https://sfpuc.org/learning/emergency-preparedness/flood-maps）查看该图自本形状文件日期以来是否已更新，或是否有任何物业审查决定确定了不再属于百年一遇洪水风险区的物业。最新官方地图、相关文档以及从审查过程中移除的物业清单均可在此网站获取。请注意，列出的物业不再被视为位于百年一遇洪水风险区内，这是物业审查过程的结果。截至2022年7月，此清单将持续更新。请访问SFPUC网站了解任何对此时间表的更改。

本区域的边界与旧金山市区物业边界相吻合。用户应确认在https://sfpuc.org/learning/emergency-preparedness/flood-maps上的Web地图的正确投影或使用，以正确识别洪水区内的物业。