{"id":2409,"date":"2026-10-11T14:12:47","date_gmt":"2026-10-11T12:12:47","guid":{"rendered":"https:\/\/geospector.de\/how-silted-up-are-stormwater-retention-basins-results-from-drone-surveys-across-germany\/"},"modified":"2026-10-19T13:28:32","modified_gmt":"2026-10-19T11:28:32","slug":"sludge-depth-retention-basins","status":"publish","type":"page","link":"https:\/\/geospector.de\/en\/sludge-depth-retention-basins\/","title":{"rendered":"How Silted Up Are Stormwater Retention Basins? Results from Drone Surveys Across Germany"},"content":{"rendered":"\t\t<div data-elementor-type=\"wp-page\" data-elementor-id=\"2409\" class=\"elementor elementor-2409 elementor-2272\" data-elementor-post-type=\"page\">\n\t\t\t\t<div class=\"elementor-element elementor-element-245f1bd e-flex e-con-boxed e-con e-parent\" data-id=\"245f1bd\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;,&quot;shape_divider_bottom&quot;:&quot;waves&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-shape elementor-shape-bottom\" aria-hidden=\"true\" data-negative=\"false\">\n\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 1000 100\" preserveAspectRatio=\"none\">\n\t<path class=\"elementor-shape-fill\" d=\"M421.9,6.5c22.6-2.5,51.5,0.4,75.5,5.3c23.6,4.9,70.9,23.5,100.5,35.7c75.8,32.2,133.7,44.5,192.6,49.7\n\tc23.6,2.1,48.7,3.5,103.4-2.5c54.7-6,106.2-25.6,106.2-25.6V0H0v30.3c0,0,72,32.6,158.4,30.5c39.2-0.7,92.8-6.7,134-22.4\n\tc21.2-8.1,52.2-18.2,79.7-24.2C399.3,7.9,411.6,7.5,421.9,6.5z\"\/>\n<\/svg>\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-52e1e70 elementor-widget elementor-widget-heading\" data-id=\"52e1e70\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<p class=\"elementor-heading-title elementor-size-default\">Technical article \u00b7 Part 3 of 3<\/p>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-fa0917a elementor-widget__width-inherit elementor-widget elementor-widget-heading\" data-id=\"fa0917a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h1 class=\"elementor-heading-title elementor-size-default\">How Silted Up Are Stormwater Retention Basins? Results from Drone Surveys Across Germany<\/h1>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-1ace01e elementor-widget elementor-widget-button\" data-id=\"1ace01e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/geospector.de\/en\/kontakt\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Arrange a consultation<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-0730eb7 e-flex e-con-boxed e-con e-parent\" data-id=\"0730eb7\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t\t\t<div class=\"elementor-element elementor-element-10e8056 elementor-widget elementor-widget-text-editor\" data-id=\"10e8056\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><em>Dipl.-Ing. David Mauro, Geospector Munich \u2013 article series \u201cStormwater retention facilities on federal highways\u201d<\/em><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ed01034 elementor-widget elementor-widget-text-editor\" data-id=\"ed01034\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p><strong>This article series presents the stormwater retention facilities along Germany\u2019s federal highways, how they work and the challenges involved in operating them. The third and final part presents current practical experience from sediment measurements across Germany, which probably provide a systematic overview of the condition of stormwater retention basins for the first time.<\/strong><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-ca78747 e-con-full e-flex e-con e-child\" data-id=\"ca78747\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-7dfa2ae elementor-widget elementor-widget-heading\" data-id=\"7dfa2ae\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">The results at a glance<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-7500e0d elementor-widget elementor-widget-text-editor\" data-id=\"7500e0d\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<ul><li><strong>23<\/strong> facilities surveyed by drone throughout Germany<\/li><li><strong>52%<\/strong> with a mean sludge depth of at least 30 cm, <strong>13%<\/strong> with at least 50 cm<\/li><li>On average <strong>189 m\u00b3<\/strong> of sludge per facility in need of cleaning<\/li><li>Neighboring basins differ greatly \u2013 <strong>each facility must be measured individually<\/strong><\/li><li>Data published by Autobahn GmbH (72 facilities) confirm the picture<\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-70b1bea elementor-widget elementor-widget-heading\" data-id=\"70b1bea\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Bathymetric surveys with drones provide an overall picture for the first time<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6a2e925 elementor-widget elementor-widget-text-editor\" data-id=\"6a2e925\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>As explained in the previous parts, the stormwater retention facilities along trunk roads must be checked regularly for sediment inflow. Sediment increasingly impairs the function of the facilities and, especially during heavy rainfall events, can cause surrounding water bodies to flood and highly toxic pollutants to be released into the environment (see <a href=\"https:\/\/geospector.de\/en\/stormwater-retention-highways\/\">Part 1<\/a>).<\/p><p>In the past, these inspections were difficult and laborious for facilities with permanently impounded water (\u201cpermanent pool\u201d) (see <a href=\"https:\/\/geospector.de\/en\/sediment-measurement-retention-basins\/\">Part 2<\/a>) and were therefore rarely carried out systematically. Newly developed drone technologies from the author\u2019s company now provide a view of the condition of the facilities in Germany for the first time. After more than four years of project experience, data can be derived from the measurements to obtain an initial overall picture.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-50ee415 elementor-widget elementor-widget-heading\" data-id=\"50ee415\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Mean sludge depth as the criterion for clean-out measures<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-57c4c1b elementor-widget elementor-widget-text-editor\" data-id=\"57c4c1b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>The facilities are designed according to hydrological criteria, above all the size of the sealed area. Operating parameters must also be defined \u2013 in particular, the sediment quantities above which proper function is no longer ensured and clean-out measures must be carried out.<\/p><p>In theory, this question is complex and depends on many factors, above all on the size and geometry of the facility, since these largely determine the buffer volume for flood protection and the flow velocity for the settling of pollutants.<\/p><p>To be as practical as possible, the criterion usually specified is an average sludge depth, typically <strong>30 cm<\/strong>, above which desludging is required.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ef43018 elementor-widget elementor-widget-heading\" data-id=\"ef43018\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Statistics on measured sludge depths in Germany \u2013 from north to south<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-791f61e elementor-widget elementor-widget-text-editor\" data-id=\"791f61e\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>A random selection of 23 typical drone surveys carried out throughout Germany in recent years gives the following picture:<\/p><table style=\"width:100%;border-collapse:collapse;margin:10px 0 20px\"><tr><th style=\"text-align:left;background:#E5F2F9;padding:8px 10px;border:1px solid #cfe0ea\">Indicator<\/th><th style=\"text-align:left;background:#E5F2F9;padding:8px 10px;border:1px solid #cfe0ea\">Number<\/th><th style=\"text-align:left;background:#E5F2F9;padding:8px 10px;border:1px solid #cfe0ea\">Share<\/th><\/tr><tr><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">Total facilities<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">23<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">100%<\/td><\/tr><tr><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">with sludge depth \u2265 30 cm<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">12<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">52%<\/td><\/tr><tr><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">with sludge depth \u2265 50 cm<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">3<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">13%<\/td><\/tr><\/table>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-cf8b1d7 elementor-widget__width-inherit elementor-widget elementor-widget-image\" data-id=\"cf8b1d7\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img fetchpriority=\"high\" decoding=\"async\" width=\"479\" height=\"243\" src=\"https:\/\/geospector.de\/wp-content\/uploads\/2026\/10\/RRB_Teil3_Statistik_Schlammtiefen.jpg\" class=\"attachment-full size-full wp-image-2254\" alt=\"Chart: mean and maximum sludge depths of 23 surveyed facilities in cm, thresholds at 30 and 50 cm\" srcset=\"https:\/\/geospector.de\/wp-content\/uploads\/2026\/10\/RRB_Teil3_Statistik_Schlammtiefen.jpg 479w, https:\/\/geospector.de\/wp-content\/uploads\/2026\/10\/RRB_Teil3_Statistik_Schlammtiefen-300x152.jpg 300w\" sizes=\"(max-width: 479px) 100vw, 479px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Mean and maximum sludge depths of the 23 surveyed facilities in cm<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-c1b235b elementor-widget elementor-widget-text-editor\" data-id=\"c1b235b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>In the author\u2019s assessment, facilities with a sludge depth of 50 cm or more indicate an increased urgency for cleaning, especially if the maximum values are also high, since the buffer or settling function is particularly at risk. This applies above all to critical single-basin facilities without cascaded basins that could compensate for part of the malfunction.<\/p><p><em>These statistics make no claim to be representative, as the sample could be biased. It is possible that only facilities already suspected of being particularly silted up were surveyed.<\/em><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ad9bbef elementor-widget elementor-widget-heading\" data-id=\"ad9bbef\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Spot checks are insufficient: neighboring basins can differ greatly<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-cc80034 elementor-widget elementor-widget-text-editor\" data-id=\"cc80034\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>In the chart above, facilities 4 to 7 lie one after another in a chain and have very different sediment quantities, which is probably due mainly to the different driving dynamics in the catchment areas (e.g. level sections vs. inclines). As a rule, it is therefore not sufficient to take spot measurements (e.g. at every fifth facility) and then assume that the facilities in between are likely to be similar. In fact, each facility has to be measured individually.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-98fda4a elementor-widget elementor-widget-heading\" data-id=\"98fda4a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Considerable quantities of sludge to be disposed of<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-6cf6541 elementor-widget elementor-widget-text-editor\" data-id=\"6cf6541\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Considering only the facilities that need to be cleaned out, the average sludge volume is <strong>189 m\u00b3 per facility<\/strong>.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-aae78d0 elementor-widget__width-inherit elementor-widget elementor-widget-image\" data-id=\"aae78d0\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"image.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t\t\t\t<figure class=\"wp-caption\">\n\t\t\t\t\t\t\t\t\t\t<img decoding=\"async\" width=\"479\" height=\"182\" src=\"https:\/\/geospector.de\/wp-content\/uploads\/2026\/10\/RRB_Teil3_Statistik_Sedimentvolumen.jpg\" class=\"attachment-full size-full wp-image-2256\" alt=\"Chart: sediment volume of the surveyed facilities in m\u00b3, mean 189 m\u00b3\" srcset=\"https:\/\/geospector.de\/wp-content\/uploads\/2026\/10\/RRB_Teil3_Statistik_Sedimentvolumen.jpg 479w, https:\/\/geospector.de\/wp-content\/uploads\/2026\/10\/RRB_Teil3_Statistik_Sedimentvolumen-300x114.jpg 300w\" sizes=\"(max-width: 479px) 100vw, 479px\" \/>\t\t\t\t\t\t\t\t\t\t\t<figcaption class=\"widget-image-caption wp-caption-text\">Sediment volume of the surveyed facilities in m\u00b3 (mean of the facilities in need of cleaning: 189 m\u00b3)<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-2022d72 elementor-widget elementor-widget-text-editor\" data-id=\"2022d72\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>As already explained in <a href=\"https:\/\/geospector.de\/en\/stormwater-retention-highways\/\">Part 1<\/a>, cleaning is laborious and costly, since the dried sludge usually has to be deposited in special landfills whose fees have risen considerably in recent years due to lack of space. On top of this come the costs of the actual cleaning work.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-ee9c6b5 elementor-widget elementor-widget-heading\" data-id=\"ee9c6b5\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Published comparative data<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-3b1fb69 elementor-widget elementor-widget-text-editor\" data-id=\"3b1fb69\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Comparative data for checking the measurements are hard to find. In summer 2024, however, Autobahn GmbH published a list of measurements for a regional highway section as part of a tender:<\/p><table style=\"width:100%;border-collapse:collapse;margin:10px 0 20px\"><tr><th style=\"text-align:left;background:#E5F2F9;padding:8px 10px;border:1px solid #cfe0ea\">Indicator<\/th><th style=\"text-align:left;background:#E5F2F9;padding:8px 10px;border:1px solid #cfe0ea\">Own drone surveys<\/th><th style=\"text-align:left;background:#E5F2F9;padding:8px 10px;border:1px solid #cfe0ea\">Autobahn GmbH (tender 2024)<\/th><\/tr><tr><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">Total facilities<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">23<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">72<\/td><\/tr><tr><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">with sludge depth \u2265 30 cm<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">12 (52%)<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">41 (57%)<\/td><\/tr><tr><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">with sludge depth \u2265 50 cm<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">3 (13%)<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">18 (25%)<\/td><\/tr><tr><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">Average volume<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">189 m\u00b3 (facilities in need of cleaning)<\/td><td style=\"padding:8px 10px;border:1px solid #cfe0ea;vertical-align:top\">148 m\u00b3<\/td><\/tr><\/table><p>It is not known whether the samples and the accuracy of the measuring methods are comparable, but the agreement with our own results is remarkably good.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-fc1a8a9 elementor-widget elementor-widget-heading\" data-id=\"fc1a8a9\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h2 class=\"elementor-heading-title elementor-size-default\">Summary<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-51c75cf elementor-widget elementor-widget-text-editor\" data-id=\"51c75cf\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Stormwater retention facilities for treating road runoff perform important functions for flood and environmental protection. During heavy rainfall events, they provide temporary storage for the large volumes of water drained from sealed road surfaces, which would otherwise quickly flood the surrounding water bodies. In addition, they prevent pollutants washed off road surfaces, some of them highly toxic such as heavy metals and microplastics, from entering the environment and the wider water cycle.<\/p><p>The pollutants settle as sludge and sediment in the deeper areas of the facilities and increasingly reduce their working volume, which can impair the settling and retention function. The quantities of sludge and sediment must therefore be checked regularly and removed \u2013 usually at considerable cost \u2013 when specified limits are exceeded.<\/p><p>Along the highways alone there are around 10,000 facilities in Germany, 6,000\u20137,000 of them with a permanent pool. Inspecting these in particular is often difficult and can then only be done by labor-intensive sounding from inflatable boats.<\/p><p>New developments in drone-based sensors and methods now offer a fast, accurate and economical alternative for the first time, allowing the sediment deposits of a large number of facilities to be checked. Projects carried out throughout Germany by the author\u2019s company in recent years provide a systematic view of the condition of the facilities for the first time, and insights can be derived for more accurate and efficient approaches to sediment determination.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-fc3b3a8 e-con-full e-flex e-con e-child\" data-id=\"fc3b3a8\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-3f42c7f elementor-widget elementor-widget-heading\" data-id=\"3f42c7f\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">The article series at a glance<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-83d178b elementor-widget elementor-widget-text-editor\" data-id=\"83d178b\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<ul><li><a href=\"https:\/\/geospector.de\/en\/stormwater-retention-highways\/\">Part 1: Introduction and functional description<\/a><\/li><li><a href=\"https:\/\/geospector.de\/en\/sediment-measurement-retention-basins\/\">Part 2: Measurement challenges for safe operation<\/a><\/li><li><strong>Part 3: Findings from drone surveys across Germany<\/strong> (this article)<\/li><li><a href=\"https:\/\/geospector.de\/en\/sediment-volume-determination\/\">Supplement: Pitfalls in determining sediment volume<\/a><\/li><\/ul>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-40257b6 e-con-full e-flex e-con e-child\" data-id=\"40257b6\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-5f11089 elementor-widget elementor-widget-heading\" data-id=\"5f11089\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<h3 class=\"elementor-heading-title elementor-size-default\">Have the sludge depth in your facilities measured?<\/h3>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-eb777f9 elementor-widget elementor-widget-text-editor\" data-id=\"eb777f9\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>With the <a style=\"color:#FFFFFF;text-decoration:underline\" href=\"https:\/\/geospector.de\/en\/sedimentbestimmung\/\">Geospector Sludge Check<\/a>, we survey the sediment surface and bed of your stormwater retention facilities area-wide by drone \u2013 without a boat and without the need for an existing baseline survey.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-d9e5e63 elementor-widget elementor-widget-button\" data-id=\"d9e5e63\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"button.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<div class=\"elementor-button-wrapper\">\n\t\t\t\t\t<a class=\"elementor-button elementor-button-link elementor-size-sm\" href=\"https:\/\/geospector.de\/en\/kontakt\/\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Arrange a consultation<\/span>\n\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/a>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-d6107cb e-con-full e-flex e-con e-child\" data-id=\"d6107cb\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\">\n\t\t\t\t<div class=\"elementor-element elementor-element-1683daf elementor-widget__width-inherit elementor-widget elementor-widget-heading\" data-id=\"1683daf\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<p class=\"elementor-heading-title elementor-size-default\">The full article is also available as a PDF download (in German).<\/p>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t<div class=\"elementor-element elementor-element-1f2c385 e-flex e-con-boxed e-con e-child\" data-id=\"1f2c385\" data-element_type=\"container\" data-e-type=\"container\">\n\t\t\t\t\t<div class=\"e-con-inner\">\n\t\t<a class=\"elementor-element elementor-element-8677370 e-con-full e-flex e-con e-child\" data-id=\"8677370\" data-element_type=\"container\" data-e-type=\"container\" data-settings=\"{&quot;background_background&quot;:&quot;classic&quot;}\" href=\"https:\/\/geospector.de\/wp-content\/uploads\/2024\/08\/Geospector_RRB_3_Praxiserfahrungen.pdf\" target=\"_blank\">\n\t\t\t\t<div class=\"elementor-element elementor-element-384af17 elementor-view-default elementor-widget elementor-widget-icon\" data-id=\"384af17\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"icon.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-icon-wrapper\">\n\t\t\t<div class=\"elementor-icon\">\n\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"40\" height=\"41\" viewBox=\"0 0 40 41\" fill=\"none\"><g 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elementor-element-3228fa4 elementor-widget elementor-widget-heading\" data-id=\"3228fa4\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<span class=\"elementor-heading-title elementor-size-default\">Part 3: Findings from drone surveys across Germany (PDF in German)<\/span>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"<p>Technical article \u00b7 Part 3 of 3 How Silted Up Are Stormwater Retention Basins? Results from Drone Surveys Across Germany Arrange a consultation Dipl.-Ing. David Mauro, Geospector Munich \u2013 article series \u201cStormwater retention facilities on federal highways\u201d This article series presents the stormwater retention facilities along Germany\u2019s federal highways, how they work and the challenges [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":2252,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"elementor_header_footer","meta":{"_acf_changed":false,"footnotes":""},"class_list":["post-2409","page","type-page","status-publish","has-post-thumbnail","hentry"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v28.6 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>How Silted Up Are Stormwater Retention Basins? 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