Flood Map for Planning (FMfP) TAN15 Defended Zones

The Flood Map for Planning (FMfP) includes climate change information to show how this will affect flood risk extents for rivers, the sea and surface water and small watercourses over the next century. It shows the potential extent of flooding assuming no defences are in place. It also indicates areas at risk from coastal erosion, areas that have flooded in the past and key information on the location of flood defence infrastructure. The FMfP can be considered as the best available information on flood risk and will replace the Development Advice Map for planning purposes in June 2023. Although it currently has no official status for planning purposes it is a useful data source when considering flood risks. More information on the formal implementation of the new TAN15 and FMfP is set out in the Written Statement from the Welsh Government - https://gov.wales/written-statement-suspension-new-technical-advice-note-15-development-flood-risk-and-coastal The FMfP introduces a new layer called the TAN15 Defended Zone. This shows areas that benefit from risk management authority owned flood defence infrastructure, that have a minimum, Present Day level of protection of: • 1% (1 in 100) annual event probability (AEP) for rivers, or • 0.5% (1 in 200) annual event probability (AEP) for the sea. Flood defences built after 1 January 2016 must also include design freeboard and an allowance for climate change. TAN15 Defended Zones are created for individual sources of flooding (i.e. Rivers or Sea). There are no TAN15 Defended Zones for Surface Water & Small Watercourses.规划用洪水地图（Flood Map for Planning, FMfP）纳入了气候变化相关信息，用以展示未来百年内，气候变化对河流、海洋、地表积水及小型水道的洪水风险影响范围。该地图展示了无防洪设施情况下的潜在洪水淹没范围，同时标注了海岸侵蚀风险区、历史洪水淹没区，以及防洪基础设施位置等关键信息。 规划用洪水地图可视为当前最优的洪水风险公开数据集，并将于2023年6月取代用于规划用途的开发咨询地图。尽管目前该数据集尚未获得规划用途的官方地位，但在开展洪水风险评估工作时，仍是极具参考价值的数据源。 关于新版TAN15与规划用洪水地图的正式实施细则，详见威尔士政府发布的书面声明：https://gov.wales/written-statement-suspension-new-technical-advice-note-15-development-flood-risk-and-coastal 规划用洪水地图新增了名为“TAN15防护区”的图层，该图层用于标识受风险管理机构所属防洪设施保护，且当前至少达到以下防洪标准的区域： • 河流类洪水：年事件概率（Annual Event Probability, AEP）1%（即每百年一遇）； • 海洋类洪水：年事件概率（Annual Event Probability, AEP）0.5%（即每两百年一遇）。 2016年1月1日后建造的防洪设施，还需纳入设计超高余量与气候变化影响预留量。 TAN15防护区仅针对单一洪水来源（即河流或海洋）设置，地表积水与小型水道洪水不设TAN15防护区。