Floodplains (MNCPPC Mylars)

After the federal government passed the Clean Water Act in 1972, MNCPPC contracted a series of floodplain studies throughout Montgomery County from the early seventies through the late eighties. These studies used the same rainfall assumptions used today in the FEMA DFIRM floodplain maps. The difference is that the MNCPPC floodplain studies include both an existing conditions analysis but also the ultimate zoning buildout floodplain analysis. This GIS layer represents the ultimate buildout floodplain analysis. As such, this floodplain is generally the most conservative for any area of the County. DPS is in charge of maintaining this layer as it's starting point from which subsequent floodplain amendments are lodged. Various cross sections of this floodplain GIS layer are tagged to a scanned analysis document which can be viewed from the popup. Aside from some of these later floodplain amendments, this original MNCPPC floodplain remains in effect for most of the county's regulatory projects. For more information, contact: GIS Manager Information Technology & Innovation (ITI) Montgomery County Planning Department, MNCPPC T: 301-650-56201972年美国联邦政府颁布《清洁水法》（Clean Water Act）后，MNCPPC于20世纪70年代初至80年代末，在蒙哥马利县境内开展了一系列洪泛区研究项目。此类研究沿用了当前联邦紧急事务管理局（FEMA）数字洪水保险费率地图（DFIRM）洪泛区图层所采用的降雨假设参数。二者的差异在于，MNCPPC的洪泛区研究同时涵盖了现状条件分析与最终区划开发洪泛区分析。本地理信息系统（GIS）图层即对应最终区划开发洪泛区的分析结果。就此而言，该洪泛区通常是全县范围内最为保守的洪泛区划方案。DPS负责维护该图层，并将其作为后续洪泛区修订申请的基准起始数据。该洪泛区GIS图层的多个断面均关联了可通过弹窗查看的扫描版分析文档。除部分后续洪泛区修订内容外，该原始MNCPPC洪泛区数据仍适用于全县绝大多数监管类项目。如需获取更多信息，请联系：蒙哥马利县规划部信息技术与创新（ITI）部门GIS管理员，MNCPPC，电话：301-650-5620