Bunclody Model HA12 Hydraulics
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South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL South Eastern CFRAM Study – Bunclody Model HA12 Hydraulics Report DOCUMENT CONTROL SHEET Client OPW Project Title South Eastern CFRAM Study Document Title IBE0601 Rp00 14_HA12 Hydraulics Report Model Name Bunclody Rev. Status Author Modeller Approved By Office of Origin Issue Date C Lewis / L D01 Draft M. Houston Howe / R G. Glasgow Belfast 24/04/2014 Clements L Howe / R F01 Draft Final R. Clements G. Glasgow Belfast 30/01/2015 Clements F02 Draft Final R. Clements L Howe / R G. Glasgow Belfast 13/08/2015 Clements IBE0601Rp0014 Rev F02 South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL Table of Reference Reports Relevant Report Issue Date Report Reference Section South Eastern CFRAM November IBE0601 Rp0001_Flood Risk Review_F01 3.3.13 Study Flood Risk Review 2011 South Eastern CFRAM IBE0601Rp00012_HA11,12&13 Inception Study Inception Report July 2012 4.3.2 Report_F02 UoM11, 12 & 13 South Eastern CFRAM January IBE0601Rp00012_HA11 12 13_Hydrology Study Hydrology Report 4.6 2014 Report_F01 UoM11, 12 and 13 South Eastern CFRAM January IBE0601Rp0016_South Eastern CFRAMS Study HA11-17 SC4 1.1 2014 Survey Contract Report_F01 Survey Contract Report 4 HYDRAULIC MODEL DETAILS ................................................................................................ 1 4.3 bunclodymodel ........................................................................................................................ 1 4.3.1 General Hydraulic Model Information .................................................................................. 1 4.3.2 Hydraulic Model Schematisation ......................................................................................... 2 4.3.3 Hydraulic Model Construction ............................................................................................ 13 4.3.4 Sensitivity Analysis ............................................................................................................ 21 4.3.5 Hydraulic Model Calibration and Verification ..................................................................... 21 4.3.6 Hydraulic Model Assumptions, Limitations and Handover Notes ...................................... 27 IBE0601Rp0014 Rev F02 South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL 4 HYDRAULIC MODEL DETAILS 4.3 BUNCLODYMODEL 4.3.1 General Hydraulic Model Information (1) Introduction: The South Eastern CFRAM Flood Risk Review (IBE0601Rp0001_Flood Risk Review) highlighted Bunclody as an Area for Further Assessment for fluvial flooding based on a review of historic flooding and the extents of flood risk determined during the PFRA. Model 3 represents the Bunclody AFA and encompasses the River Slaney upstream and downstream of its extent, plus associated tributaries. The total contributing area at the downstream limit of the model is 1,036km 2. A total of 54% of this comes from Model 2 (Tullow&Tullowphelim) which enters Model 3 (Bunclody) at the upstream extent.Model 3 (Bunclody) enters Model 4 (Enniscorthy) at its downstream extent. There are three gauging stations located along the length of the Bunclody model: • Scarawalsh (12001) – This gauge has an FSU rating of A2. • Clohamon (12027) – This gauge is inactive and has no flow or level data. • Bunclody (12033) – This gauge is inactive and has no flow or level data. Further information on these gauges is provided in Section 4.3.5. A rating review was carried out for the Scarawalsh gauge in order to derive new Q med values at the station. See Section 4.9.5 for full review details. A NAM model was constructed for Station 12001 and its contributing catchment. Radar data was not available for use as rainfall input data so spatial and temporal data was derived on an area weighed basis from three hourly stations, Oak Park, Rosslare and Casement. Calibration in terms of mass-balance (between 1996 and 2010) was not considered robust with simulated water mass lower than observed. 3 Calibration to observed flow was not strong resulting in a Q med value of 143m /s. Whilst this is in between the FSU predicted value of 138m 3/s and gauge value of 156.27 m 3/s it is considered appropriate to proceed with the gauged value given that the station is already FSU A2 classified with a 48 year record. A number of watercourses have been designated as high priority in theBunclody model,including the River Clody, Barkers Stream, Carhill Stream, Mill Stream and a portion of the River Slaney which passes through the AFA. These reaches have been modelled as 1D-2D using the MIKE suite of software. The Bunclody Mill Run and the River Slaney; upstream and downstream of the AFA the Slaney River are designated as MPW and have been modelled as 1D using the MIKE suite of software. (2) Model Reference: HA12_BUNC3 IBE0601Rp0014 4.3-1 Rev F02 South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL (3) AFAs included in the model: Bunclody (4) Primary Watercourses / Water Bodies (including local names): Reach IDName SLAN SLANEY 12001 BARK BARKER STREAM LINK BCMR CLOHAMON BLIK BARKERS LINK CARR CARHILL RIVER MILR MILL RACE STRA STRAW CLOD CLODY RIVER MILS MILL STREAM (5) Software Type (and version): (a) 1D Domain: (b) 2D Domain: (c) Other model elements: MIKE 11 (2011) MIKE 21- Rectangular Mesh (2011) MIKE FLOOD (2011) 4.3.2 Hydraulic Model Schematisation (1) Map of Model Extents: Figure 4.3.1 and 4.3.2 illustrate the extent of the modelled catchment, river centre line, HEP locations and AFA extents. The Slaney catchment contains 4 Upstream Limit HEPs, 1 Downstream Limit HEP, 3 Gauging Station HEPs (two of which are inactive), 6 Intermediate HEPs and 11 Tributary HEP (three of which are modelled). IBE0601Rp0014 4.3-2 Rev F02 South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL Figure 4.3.1 Map of Model Extents IBE0601Rp0014 4.3-3 Rev F02 South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL Figure 4.3.2 Map of Model Extents at the AFA (2) x-y Coordinates of River (Upstream extent): Table 4.3.1 Location of Rivers River Name x y SLAN SLANEY 12001 287833 164807 BARK BARKER STREAM 289430 156785 BCMR CLOHAMON 293289 154766 CARR CARHILL RIVER 292149 158047 MILR MILL RACE 290483 156369 STRA STRAW 292011 158191 CLOD CLODY RIVER 289806 155046 MILS MILL STREAM 289905 155176 (3) Total Modelled Watercourse Length: 39kms (approx.) (4) 1D Domain only Watercourse Length: 22.7 kms (5) 1D-2D Domain 16.3 kms (approx.) (approx.) Watercourse Length: IBE0601Rp0014 4.3-4 Rev F02 South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL (6) 2D Domain Mesh Type / Resolution / Area: Rectangular / 5 metres / 20 km 2(approx.) (7) 2D Domain Model Extent: Figure 4.3.3 2D Model Extent Figure 4.3.3 shows the extent of the LiDAR data used in the 2D model. Buildings are illustrated in black. For details of the approach to modelling of buildings in the 2D area, please refer to section 3.3.2 of this report. Figure 4.3.4 Shows the extent of the NDHM data used. The black line shows the river network and the red boundary represents the LiDAR extent (as shown in Figure 4.3.3). A buffer zone was created between the two datasets which were smoothed together by interpolation. IBE0601Rp0014 4.3-5 Rev F02 South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL Figure 4.3.4 NHDM Extent Figure 4.3.5shows an overview drawing of the model schematisation. Figures 4.3.6 and 4.3.7showdetailed views of critical structures in the model. The overview design diagram covers the model, extents, showing surveyed cross-section locations, AFA boundary and river centreline. It also shows the area covered by flooding n the 2D model domain. The detailed areas are provided where there is the most significant risk of flooding. These diagrams include the surveyed cross-section locations, AFA boundary and river centreline. They also show the location of the critical structures as discussed in Section 4.3.3(1) along with the location and extent of the links between the 1D and 2D models. IBE0601Rp0014 4.3-6 Rev F02 South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL Figure 4.3.5 Model Schematic Overview (A - Full Extent) IBE0601Rp0014 4.3-7 Rev F02 South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL Figure 4.3.6 Model Schematic Overview - Critical Structures (B - AFA Section) Figure 4.3.7 Model Schematic Overview - Critical Structures (C - MPW Section) IBE0601Rp0014 4.3-8 Rev F02 South Eastern CFRAM Study HA12 Hydraulics Report –DRAFT FINAL (8) Survey Information (a) Survey Folder Structure: First Level Folder Second Level Folder Third Level Folder CCS_S12_M03_12SLAN2_Final_WP3_1303 Data Files 21 GIS Where:Bunclody CCS – Surveyor Name Drawings S12 – South Eastern CFRAM Study Area, Hydrometric Area 12 M03 – Model Number 3 Photos 12SLAN2– River Reference Final - Version WP3 – Work Package 3 st Videos 130321 – Date Issued (21 Mar 2013) PDF (b) Survey Folder References: Reach IDName File Ref. SLAN SLANEY 12001 CCS_S12_M03_04_12SLAN5_ Final_WP3_130321 CCS_S12_M03_12SLAN2_Final_WP3_130321 CCS_S12_M03_12SLAN3_Final_WP3_130321 CCS_S12_M03_12SLAN4_ Final_WP3_130321 CCS_S12_M03_04_Scarwalsh_12001_Final_WP1_130123 BARK BARKER STREAM LINK CCS_S12_M03_12BARK_Final_WP3_130321 BCMR CLOHAMON CCS_S12_M03_12BCMR_Final_WP3_130424 BLIK BARKERS LINK CCS_S12_M03_12BLIK_Final_WP3_130321 CARR CARHILL RIVER CCS_S12_M03_12CARR_Final_WP3_130321 MILR MILL RACE CCS_S12_M03_12MILR_Final_WP3_130321 STRA STRAW CCS_S12_M03_12STRA_Final_WP3_130321 CLOD CLODY RIVER CCS_S12_M03_12CLOD_Final_WP3_130321 MILS MILL STREAM CCS_S12_M03_12MILS_Final_WP3_130321