diff --git a/source/Classes/TimeSeriesFile.vb b/source/Classes/TimeSeriesFile.vb
index 2fc1fc81..482ec4fe 100644
--- a/source/Classes/TimeSeriesFile.vb
+++ b/source/Classes/TimeSeriesFile.vb
@@ -32,6 +32,8 @@ Public MustInherit Class TimeSeriesFile
         CSV
         DFS0
         GISMO_WEL
+        HYBNAT_BCS
+        HYBNAT_WEL
         HYDRO_AS_DAT
         HYSTEM_WEL
         JAMS
@@ -63,6 +65,7 @@ Public MustInherit Class TimeSeriesFile
     ''' </remarks>
     Public MustInherit Class FileExtensions
         Public Shared ReadOnly ASC As String = ".ASC"
+        Public Shared ReadOnly BCS As String = ".BCS"   'BGS HYBNAT BCS format
         Public Shared ReadOnly BIN As String = ".BIN"   'SYDRO binary format
         Public Shared ReadOnly CSV As String = ".CSV"
         Public Shared ReadOnly DAT As String = ".DAT"
@@ -73,7 +76,7 @@ Public MustInherit Class TimeSeriesFile
         Public Shared ReadOnly REG As String = ".REG"
         Public Shared ReadOnly SMB As String = ".SMB"
         Public Shared ReadOnly TEN As String = ".TEN"
-        Public Shared ReadOnly TXT As String = ".TXT"   'SWMM routing interface file, SWMM LID report file or generic text file 
+        Public Shared ReadOnly TXT As String = ".TXT"   'SWMM routing interface file, SWMM LID report file or generic text file
         Public Shared ReadOnly UVF As String = ".UVF"
         Public Shared ReadOnly WBL As String = ".WBL"   'SYDRO binary WEL format
         Public Shared ReadOnly WEL As String = ".WEL"
@@ -92,6 +95,7 @@ Public MustInherit Class TimeSeriesFile
         "Text files (*.txt)|*.txt|" &
         "CSV files (*.csv)|*.csv|" &
         "DHI MIKE DFS0 files (*.dfs0)|*.dfs0|" &
+        "HYBNAT files (*.bcs, *.wel)|*.bcs;*.wel|" &
         "HYDRO_AS-2D result files (*.dat)|*.dat|" &
         "Hystem-Extran files (*.dat, *.reg)|*.dat;*.reg|" &
         "JAMS timeseries result files (*.dat)|*.dat|" &
@@ -154,7 +158,7 @@ Public MustInherit Class TimeSeriesFile
     End Property
 
     ''' <summary>
-    ''' Stores the TimeSeries read from the file. 
+    ''' Stores the TimeSeries read from the file.
     ''' The key corresponds to the column index stored as <seealso cref="TimeSeriesInfo.Index"/> in <seealso cref="TimeSeriesInfos"/>.
     ''' </summary>
     Public TimeSeries As Dictionary(Of Integer, TimeSeries)
@@ -347,7 +351,7 @@ Public MustInherit Class TimeSeriesFile
     ''' </summary>
     ''' <param name="index">Index of the desired timeseries within the file</param>
     ''' <returns>The timeseries</returns>
-    ''' <remarks>If the timeseries has not been imported yet, an import is initiated. 
+    ''' <remarks>If the timeseries has not been imported yet, an import is initiated.
     ''' Throws an exception if the timeseries cannot be found in the file.</remarks>
     Public ReadOnly Property getTimeSeries(Optional index As Integer = 0) As TimeSeries
         Get
@@ -369,7 +373,7 @@ Public MustInherit Class TimeSeriesFile
     ''' </summary>
     ''' <param name="title">Title of the desired timeseries.</param>
     ''' <returns>The timeseries</returns>
-    ''' <remarks>If the timeseries has not been imported yet, an import is initiated. 
+    ''' <remarks>If the timeseries has not been imported yet, an import is initiated.
     ''' Throws an exception if the timeseries cannot be found in the file.</remarks>
     Public ReadOnly Property getTimeSeries(title As String) As TimeSeries
         Get
@@ -530,6 +534,10 @@ Public MustInherit Class TimeSeriesFile
                 Return FileExtensions.DFS0
             Case FileTypes.GISMO_WEL
                 Return FileExtensions.ASC
+            Case FileTypes.HYBNAT_BCS
+                Return FileExtensions.BCS
+            Case FileTypes.HYBNAT_WEL
+                Return FileExtensions.WEL
             Case FileTypes.HYDRO_AS_DAT
                 Return FileExtensions.DAT
             Case FileTypes.HYSTEM_WEL
@@ -635,6 +643,11 @@ Public MustInherit Class TimeSeriesFile
                     fileType = FileTypes.ASC
                 End If
 
+            Case FileExtensions.BCS
+                'HYBNAT BCS file
+                Log.AddLogEntry(levels.info, $"Assuming HYBNAT BCS format for file {fileName}.")
+                fileType = FileTypes.HYBNAT_BCS
+
             Case FileExtensions.BIN
                 'SYDRO binary file
                 Log.AddLogEntry(levels.info, $"Assuming SYDRO binary format for file {fileName}.")
@@ -754,6 +767,10 @@ Public MustInherit Class TimeSeriesFile
                     'SYDRO binary WEL file
                     Log.AddLogEntry(levels.info, $"Detected SYDRO binary WEL format for file {fileName}.")
                     fileType = FileTypes.WBL
+                ElseIf Fileformats.HYBNAT_WEL.verifyFormat(file) Then
+                    'HYBNAT WEL file
+                    Log.AddLogEntry(levels.info, $"Detected HYBNAT WEL format for file {fileName}.")
+                    fileType = FileTypes.HYBNAT_WEL
                 End If
 
             Case FileExtensions.WVP
@@ -816,6 +833,10 @@ Public MustInherit Class TimeSeriesFile
                 FileInstance = New Fileformats.DFS0(file)
             Case FileTypes.GISMO_WEL
                 FileInstance = New Fileformats.GISMO_WEL(file)
+            Case FileTypes.HYBNAT_BCS
+                FileInstance = New Fileformats.HYBNAT_BCS(file)
+            Case FileTypes.HYBNAT_WEL
+                FileInstance = New Fileformats.HYBNAT_WEL(file)
             Case FileTypes.HYSTEM_REG
                 FileInstance = New Fileformats.HystemExtran_REG(file)
             Case FileTypes.HYSTEM_WEL
diff --git a/source/FileFormats/HYBNAT_BCS.vb b/source/FileFormats/HYBNAT_BCS.vb
new file mode 100644
index 00000000..a5c56a93
--- /dev/null
+++ b/source/FileFormats/HYBNAT_BCS.vb
@@ -0,0 +1,186 @@
+'BlueM.Wave
+'Copyright (C) BlueM Dev Group
+'<https://www.bluemodel.org>
+'
+'This program is free software: you can redistribute it and/or modify
+'it under the terms of the GNU Lesser General Public License as published by
+'the Free Software Foundation, either version 3 of the License, or
+'(at your option) any later version.
+'
+'This program is distributed in the hope that it will be useful,
+'but WITHOUT ANY WARRANTY; without even the implied warranty of
+'MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+'GNU Lesser General Public License for more details.
+'
+'You should have received a copy of the GNU Lesser General Public License
+'along with this program.  If not, see <https://www.gnu.org/licenses/>.
+'
+Imports System.IO
+
+Namespace Fileformats
+
+    ''' <summary>
+    ''' Class for HYBNAT BCS files
+    ''' </summary>
+    Public Class HYBNAT_BCS
+        Inherits TimeSeriesFile
+
+        ''' <summary>
+        ''' The unit of the time series
+        ''' </summary>
+        ''' <remarks> Is fixed for each type of file</remarks>
+        Private _unit As String
+
+        ''' <summary>
+        ''' Referencedate for the beginning of the simulation
+        ''' </summary>
+        ''' <remarks>default: 01.01.2000 00:00:00</remarks>
+        Public refDate As DateTime
+
+        ''' <summary>
+        ''' Set if the import dialog should be used
+        ''' </summary>
+        ''' <value></value>
+        ''' <returns>True</returns>
+        ''' <remarks></remarks>
+        Public Overrides ReadOnly Property UseImportDialog() As Boolean
+            Get
+                Return True
+            End Get
+        End Property
+
+        ''' <summary>
+        ''' Instanciates a new HYBNAT BCS file
+        ''' </summary>
+        ''' <param name="file">Path to file</param>
+        ''' <remarks></remarks>
+        Public Sub New(file As String)
+
+            Call MyBase.New(file)
+
+            'Default settings
+            iLineHeadings = 1
+            iLineData = 2
+            UseUnits = False
+            _unit = "m³/s"
+            IsColumnSeparated = True
+            Separator = Constants.semicolon
+            DateTimeColumnIndex = 0
+            refDate = New DateTime(2000, 1, 1, 0, 0, 0)
+
+            Call readSeriesInfo()
+
+        End Sub
+
+        ''' <summary>
+        ''' Checks if the file is a HYBNAT BCS file
+        ''' </summary>
+        ''' <param name="file">Path to file</param>
+        ''' <returns>Boolean</returns>
+        ''' <remarks>Check is based on file extension and line 1 (must start with "time;")</remarks>
+        Public Shared Function verifyFormat(file As String) As Boolean
+            'Check if file name ends with ".bcs"
+            Dim filename As String = Path.GetFileName(file).ToLower()
+            If Not filename.EndsWith(".bcs") Then Return False
+
+            'Open file
+            Dim stream As New FileStream(file, FileMode.Open, IO.FileAccess.Read)
+            Dim reader As New StreamReader(stream, System.Text.Encoding.Default)
+            Dim syncReader = TextReader.Synchronized(reader)
+
+            'Check if first line starts with "time;"
+            If Not syncReader.ReadLine.ToString.Trim().StartsWith("time;") Then Return False
+
+            'Close file
+            syncReader.Close()
+            reader.Close()
+            stream.Close()
+
+            'File is valid
+            Return True
+        End Function
+
+        ''' <summary>
+        ''' Read number of columns and their names
+        ''' </summary>
+        ''' <remarks></remarks>
+        Public Overrides Sub readSeriesInfo()
+            'Clear series infos
+            TimeSeriesInfos.Clear()
+
+            'Open file
+            Dim stream As New FileStream(File, FileMode.Open, IO.FileAccess.Read)
+            Dim reader As New StreamReader(stream, System.Text.Encoding.Default)
+            Dim syncReader = TextReader.Synchronized(reader)
+
+            'Read first line for column names
+            Dim columnNames() As String = syncReader.ReadLine.Split(Separator.ToChar)
+
+            'Close file
+            syncReader.Close()
+            reader.Close()
+            stream.Close()
+
+            'Store series info
+            For i = 0 To columnNames.Count - 1
+                'Overjump time column and empty columns
+                If i = DateTimeColumnIndex Then Continue For
+                If columnNames(i).Trim() = "" Then Continue For
+
+                'Add series info
+                Dim seriesInfo = New TimeSeriesInfo With {
+                    .Name = columnNames(i).Trim(),
+                    .Unit = _unit,
+                    .Index = i + 1
+                }
+                TimeSeriesInfos.Add(seriesInfo)
+            Next
+        End Sub
+
+        ''' <summary>
+        ''' Reads the time series from the file
+        ''' </summary>
+        ''' <remarks></remarks>
+        Public Overrides Sub readFile()
+            'Show dialog for setting the reference date
+            Dim dlg As New HYDRO_AS_2D_Diag()
+            dlg.ShowDialog()
+            refDate = dlg.DateTimePicker_refDate.Value
+
+            'Instantiate time series
+            For Each seriesInfo As TimeSeriesInfo In SelectedSeries
+                Dim timeSeries = New TimeSeries(seriesInfo.Name) With {
+                    .Unit = seriesInfo.Unit,
+                    .DataSource = New TimeSeriesDataSource(File, seriesInfo.Name),
+                    .Interpretation = BlueM.Wave.TimeSeries.InterpretationEnum.Instantaneous
+                }
+                MyBase.TimeSeries.Add(seriesInfo.Index, timeSeries)
+            Next
+
+            'Open file and overjump line with headings
+            Dim stream As New FileStream(Me.File, FileMode.Open, IO.FileAccess.Read)
+            Dim reader As New StreamReader(stream, Me.Encoding)
+            Dim syncReader = TextReader.Synchronized(reader)
+            syncReader.ReadLine()
+
+            'Read data until end of file
+            Do
+                'Get values and datetime (calculate from reference date and seconds)
+                Dim values = syncReader.ReadLine.Split(Separator.ToChar)
+                Dim datetime = refDate + New TimeSpan(0, 0, Helpers.StringToDouble(values(DateTimeColumnIndex)))
+
+                'Add nodes to time series
+                For Each seriesInfo As TimeSeriesInfo In SelectedSeries
+                    TimeSeries(seriesInfo.Index).AddNode(datetime, Helpers.StringToDouble(values(seriesInfo.Index - 1)))
+                Next
+            Loop Until syncReader.Peek() = -1
+
+            'Close file
+            syncReader.Close()
+            reader.Close()
+            stream.Close()
+        End Sub
+
+    End Class
+
+End Namespace
\ No newline at end of file
diff --git a/source/FileFormats/HYBNAT_WEL.vb b/source/FileFormats/HYBNAT_WEL.vb
new file mode 100644
index 00000000..a8ded348
--- /dev/null
+++ b/source/FileFormats/HYBNAT_WEL.vb
@@ -0,0 +1,260 @@
+'BlueM.Wave
+'Copyright (C) BlueM Dev Group
+'<https://www.bluemodel.org>
+'
+'This program is free software: you can redistribute it and/or modify
+'it under the terms of the GNU Lesser General Public License as published by
+'the Free Software Foundation, either version 3 of the License, or
+'(at your option) any later version.
+'
+'This program is distributed in the hope that it will be useful,
+'but WITHOUT ANY WARRANTY; without even the implied warranty of
+'MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+'GNU Lesser General Public License for more details.
+'
+'You should have received a copy of the GNU Lesser General Public License
+'along with this program.  If not, see <https://www.gnu.org/licenses/>.
+'
+Imports System.IO
+
+Namespace Fileformats
+
+    ''' <summary>
+    ''' Class for HYBNAT WEL files
+    ''' </summary>
+    Public Class HYBNAT_WEL
+        Inherits TimeSeriesFile
+
+        ''' <summary>
+        ''' The name of the element in the WEL-file
+        ''' </summary>
+        ''' <remarks></remarks>
+        Private _elmentName As String
+
+        ''' <summary>
+        ''' The element type in the WEL-file
+        ''' </summary>
+        ''' <remarks>
+        ''' First character of the element name
+        ''' (
+        ''' N: natural catchment
+        ''' K: urban catchment
+        ''' E: point discharge
+        ''' P: observation station
+        ''' T: transport element
+        ''' V: branching element
+        ''' B: reservoir
+        ''' )
+        ''' </remarks>
+        Private _elementType As Char
+
+        ''' <summary>
+        ''' Referencedate for the beginning of the simulation
+        ''' </summary>
+        ''' <remarks>default: 01.01.2000 00:00:00</remarks>
+        Public refDate As DateTime
+
+        ''' <summary>
+        ''' Set if the import dialog should be used
+        ''' </summary>
+        ''' <value></value>
+        ''' <returns>True</returns>
+        ''' <remarks></remarks>
+        Public Overrides ReadOnly Property UseImportDialog() As Boolean
+            Get
+                Return True
+            End Get
+        End Property
+
+        ''' <summary>
+        ''' Instanciates a new HYBNAT WEL file
+        ''' </summary>
+        ''' <param name="file">Path to file</param>
+        ''' <remarks></remarks>
+        Public Sub New(file As String)
+
+            Call MyBase.New(file)
+
+            'Default settings
+            UseUnits = True
+            IsColumnSeparated = True
+            DateTimeColumnIndex = 0
+            refDate = New DateTime(2000, 1, 1, 0, 0, 0)
+
+            Call readSeriesInfo()
+
+        End Sub
+
+        ''' <summary>
+        ''' Checks if the file is a HYBNAT WEL files
+        ''' </summary>
+        ''' <param name="file">Path to file</param>
+        ''' <returns>Boolean</returns>
+        ''' <remarks>Check is based on line 4 (must start with "Ganglinien:")</remarks>
+        Public Shared Function verifyFormat(file As String) As Boolean
+            'Check if file name ends with .wel
+            Dim filename As String = Path.GetFileName(file).ToLower()
+            If Not filename.EndsWith(".wel") Then Return False
+
+            'Open file
+            Dim stream As New FileStream(file, FileMode.Open, IO.FileAccess.Read)
+            Dim reader As New StreamReader(stream, System.Text.Encoding.Default)
+            Dim syncReader = TextReader.Synchronized(reader)
+
+            'Overjump first 3 lines
+            For i = 1 To 3
+                syncReader.ReadLine()
+            Next
+
+            'Check if line 4 starts with "Ganglinien:"
+            If Not syncReader.ReadLine.ToString.Trim().StartsWith("Ganglinien:") Then Return False
+
+            'Close file
+            syncReader.Close()
+            reader.Close()
+            stream.Close()
+
+            'Valid file
+            Return True
+        End Function
+
+        ''' <summary>
+        ''' Read number of columns and their names
+        ''' </summary>
+        ''' <remarks></remarks>
+        Public Overrides Sub readSeriesInfo()
+            'Clear series infos
+            TimeSeriesInfos.Clear()
+
+            'Open file
+            Dim stream As New FileStream(File, FileMode.Open, IO.FileAccess.Read)
+            Dim reader As New StreamReader(stream, System.Text.Encoding.Default)
+            Dim syncReader = TextReader.Synchronized(reader)
+
+            'Overjump first 3 lines
+            For i = 1 To 3
+                syncReader.ReadLine()
+            Next
+
+            'Determine element name and type
+            _elmentName = syncReader.ReadLine.ToString.Split(":")(1).Split("/")(0).Trim()
+            _elementType = _elmentName.Substring(0, 1)
+
+            'Jump back to beginning of file
+            stream.Seek(0, SeekOrigin.Begin)
+            reader = New StreamReader(stream, Me.Encoding)
+            syncReader = TextReader.Synchronized(reader)
+
+            'Set line numbers for headings, units and data according to element type
+            Select Case _elementType
+                Case "N", "K", "T", "B"
+                    iLineHeadings = 17
+                    iLineUnits = 18
+                    iLineData = 20
+                Case "E"
+                    iLineHeadings = 8
+                    iLineUnits = 9
+                    iLineData = 11
+                Case "P"
+                    iLineHeadings = 11
+                    iLineUnits = 12
+                    iLineData = 14
+                Case "V"
+                    iLineHeadings = 14
+                    iLineUnits = 15
+                    iLineData = 17
+                Case Else
+                    Throw New Exception($"Unknown HYBNAT element type '{_elementType}'!")
+            End Select
+
+            'Overjump lines until headings
+            For i = 1 To iLineHeadings - 1
+                syncReader.ReadLine()
+            Next
+
+            'Read headings and units
+            Dim columnNames() As String = syncReader.ReadLine.Split(New Char() {" "}, System.StringSplitOptions.RemoveEmptyEntries)
+            Dim columnUnits() As String = syncReader.ReadLine.Split(New Char() {" "}, System.StringSplitOptions.RemoveEmptyEntries)
+
+            'Close file
+            syncReader.Close()
+            reader.Close()
+            stream.Close()
+
+            'Store series info
+            For i = 0 To columnNames.Count - 1
+                'Overjump time column
+                If i = DateTimeColumnIndex Then Continue For
+
+                'Rename units
+                If columnUnits(i) = "cbm/s" Then columnUnits(i) = "m³/s"
+
+                'Add series info
+                Dim seriesInfo = New TimeSeriesInfo With {
+                    .Name = $"{_elmentName} ({columnNames(i)})",
+                    .Unit = columnUnits(i),
+                    .Index = i + 1
+                }
+                TimeSeriesInfos.Add(seriesInfo)
+            Next
+        End Sub
+
+        ''' <summary>
+        ''' Reads the time series from the file
+        ''' </summary>
+        ''' <remarks></remarks>
+        Public Overrides Sub readFile()
+            'Show dialog for setting the reference date
+            Dim dlg As New HYDRO_AS_2D_Diag()
+            dlg.ShowDialog()
+            refDate = dlg.DateTimePicker_refDate.Value
+
+            'Instantiate time series
+            For Each sInfo As TimeSeriesInfo In SelectedSeries
+                Dim timeSeries = New TimeSeries(sInfo.Name) With {
+                    .Unit = sInfo.Unit,
+                    .DataSource = New TimeSeriesDataSource(File, sInfo.Name)
+                }
+
+                'Set interpretation mode
+                If timeSeries.Unit = "mm" Then
+                    timeSeries.Interpretation = BlueM.Wave.TimeSeries.InterpretationEnum.BlockRight
+                Else
+                    timeSeries.Interpretation = BlueM.Wave.TimeSeries.InterpretationEnum.Instantaneous
+                End If
+
+                MyBase.TimeSeries.Add(sInfo.Index, timeSeries)
+            Next
+
+            'Open file
+            Dim stream As New FileStream(Me.File, FileMode.Open, IO.FileAccess.Read)
+            Dim reader As New StreamReader(stream, Me.Encoding)
+            Dim syncReader = TextReader.Synchronized(reader)
+
+            'Overjump lines with headings and units
+            For i = 1 To iLineData - 1
+                syncReader.ReadLine()
+            Next
+
+            'Read data
+            Do
+                'Get values and datetime (calculate from reference date and hours, round to full minutes)
+                Dim values() As String = syncReader.ReadLine.Split(New Char() {" "}, System.StringSplitOptions.RemoveEmptyEntries)
+                If values(0).StartsWith("-") Then Exit Do
+                Dim datetime = refDate + New TimeSpan(0, Helpers.StringToDouble(values(0)) * 60, 0)
+
+                'Add nodes to time series
+                For Each seriesInfo As TimeSeriesInfo In SelectedSeries
+                    TimeSeries(seriesInfo.Index).AddNode(datetime, Helpers.StringToDouble(values(seriesInfo.Index - 1)))
+                Next
+            Loop Until syncReader.Peek() = -1
+
+            'Close file
+            syncReader.Close()
+            reader.Close()
+            stream.Close()
+        End Sub
+
+    End Class
+
+End Namespace
\ No newline at end of file
diff --git a/source/Wave.vbproj b/source/Wave.vbproj
index 0f283d09..47d3e48c 100644
--- a/source/Wave.vbproj
+++ b/source/Wave.vbproj
@@ -215,6 +215,8 @@
       <SubType>Form</SubType>
     </Compile>
     <Compile Include="Classes\TimeSeriesDisplayOptions.vb" />
+    <Compile Include="FileFormats\HYBNAT_BCS.vb" />
+    <Compile Include="FileFormats\HYBNAT_WEL.vb" />
     <Compile Include="FileFormats\JAMS.vb" />
     <Compile Include="Main.vb" />
     <Compile Include="App.vb" />