Table of Contents: Section 1: Introduction ..........................................................................................4 1.1 Purpose .......................................................................................................4 1.2 Project Authority ..........................................................................................4 1.3 Project Location...........................................................................................5 1.4 Methodologies Used for Hydrology and Hydraulics.....................................5 1.5 Acknowledgements .....................................................................................5 1.6 Study Results ..............................................................................................5 Section 2.1: General Information.......................................................................9 Section 2.2: Mapping Information......................................................................9 Section 2.3: Hydrology ......................................................................................9 Section 2.4: Hydraulics......................................................................................9 Section 2.5: Additional Study Information:.........................................................9 Section 3: Survey and Mapping Information .......................................................10 3.1 Field Survey Information ...........................................................................10 3.2 Mapping ....................................................................................................10 Section 4: Hydrology...........................................................................................10 4.1 Method description. ...................................................................................10 4.2 Parameter estimation. ...............................................................................10 4.3 Problems encountered during the study. ...................................................15 4.4 Calibration. ................................................................................................15 4.5 Final results. ..............................................................................................15 Section 5: Hydraulics ..........................................................................................17 5.1 Method description. ...................................................................................17 5.2 Work study maps.......................................................................................17 5.3 Parameter estimation. ...............................................................................17 5.5 Modeling considerations............................................................................18 5.6 Floodway modeling ...................................................................................18 5.7 Problems encountered during the study. ...................................................19 5.8 Calibration. ................................................................................................19 5.9 Final results. ..............................................................................................19 Section 6: Erosion and Sediment Transport .......................................................19 Section 7: Ratio of the top width of 100-yr and 25-yr floodplain..........................20 2 List of Figures: Figure 1.1 –Watershed Map .................................................................................6 Figure 1.2 – Study Limit ........................................................................................7 Figure 1.3 – Soil Classification..............................................................................8 Figure 4.1 – Flow Chart of Mapping Process......................................................12 List of Tables: Table 4.1 - Methods used for a HEC-HMS analysis............................................10 Table 4.2 - Sub-basin Characteristics .................................................................14 Table 4.3 - Sub-basin discharges .......................................................................15 Table 4.4 – Summary of 100-yr Peak Discharge Values ....................................16 Table 4.5 – Summary of 25-yr Peak Discharge Values ......................................16 Table 4.6 – Summary of 500-yr Peak Discharge Values ....................................16 Table 4.7 – Comparison of 100-yr Peak Discharge Values ................................16 Exhibit Exhibit 1 100-yr Floodplain Limit Map for the Craycroft Wash Exhibit 2 Annotated Flood Insurance Rate Map for the Craycroft Wash Attached CD TDN with supporting models and GIS data. 3 Section 1: Introduction 1.1 Purpose The purpose of this study is to provide flood and erosion hazard information for the Craycroft Wash for use by the Pima County Regional Flood Control District (District) in floodplain use permitting and floodplain management. More specifically, it provides: • discharge values for sub-basins and important concentration points; • hydrographs for use with floodplain mapping; • floodplain mapping for channels with contributing areas greater than 1 square mile, and channels with 100-yr discharges greater than 2000 cfs, which are treated differently under the Pima County Ordinance. 1.2 Project Authority The State of Arizona has delegated the responsibility to each county flood control district to adopt floodplain regulations designed to promote the public health, safety and general welfare of its citizenry as provided under the Arizona Revised Statutes, Title 48, Chapter 21, Article 1, Sections 48-3601 through 3627. More specifically, A.R.S. 3609 directs county flood control districts to adopt floodplain regulations that: A. Regulate all development of land, construction of residential, commercial or industrial structures or uses of any kind which may divert, retard or obstruct flood water and threaten public health or safety or the general welfare; and B. Establish minimum flood protection elevations and flood damage prevention requirements for uses, structures and facilities which are vulnerable to flood damage; and C. Comply with state and local land use plans and ordinances, if any. In conformance with A.R.S. 3609, this ordinance provides for protection of the public health safety and welfare by regulation of flood and erosion hazard areas to control flood hazards and prevent repetitive loss from flood damage. D. The flood hazard areas of Pima County are subject to periodic inundation which may result in loss of life and property, create health and safety hazards, disrupt commerce and governmental services, require extraordinary public expenditures for flood protection and relief, and impair the tax base, all of which adversely affect the public health, safety, and general welfare. E. These flood losses are caused by the cumulative effect of obstructions in areas of special flood hazards which increase flood heights, flow velocities, and cause flood and erosion damage. Uses that are inadequately flood-proofed, elevated, or otherwise protected from flood damage, also contribute to the flood loss. (Ord. 2005 FC-2 § 2 (part), 2005). Section 16 of the Pima County Ordinance describes the provisions for floodplain regulation in Pima County. 4 1.3 Project Location The study was performed to provide drainage information for the Craycroft Wash. The site includes Sections 1, 11-14, 23-25 of Township 13 South, Range 14 East, Sections 7 of Township 13 South, Range 15 East, and Sections 36 of Township 12 South, Range 14 East, Pima County, Arizona. Entire watershed of the Craycroft Wash is in FEMA Zone X, as shown on the current Flood Insurance Rate Map (FIRM) number 04019C-1644, 1663 and 1665K. The watershed is 3.16 square mile. The study watershed was divided into ten subwatersheds while the study reach was divided into there segments (Fig.1.1). The study limit is south of Sunrise Dr for a main channel and south of Sunrise Dr. for the eastern tributary (Fig.1.2). The downstream study limit is the confluence with the Rillito River. 1.4 Methodologies Used for Hydrology and Hydraulics Topographic, hydrologic and hydraulic analyses were performed to determine drainage conditions in Craycroft wash. ArcGIS, Version 9.3, HEC-HMS version 3.4 (HEC-HMS), Hec-RAS Version 4.0 (HEC-RAS), and HEC-GeoRAS, Version 4.1.1 (HEC-GeoRAS) were used for the analyses. 1.5 Acknowledgements This study relied on assistance of RFCD GIS staff, who were integral to the development of the models and maps. 1.6 Study Results The modeled discharge for the Craycroft Wash at the confluence with the Rillito River is 3620 cfs, where the area is 3.16 square miles. Floodplain was mapped for watersheds greater than one square mile in this study. The study found some homes at risk for flooding during the 100-yr flood. A 500-yr floodplain limit was also mapped. In-general, the footprint of the 500-yr floodplain is only slightly larger than the 100-yr floodplain. 5 Figure 1.1 Watershed Map Craycroft Wash ! ( Disharge Points 50 Foot Contour Subbasins SKYLINE CCT A CCT B CCT C KO LB CCT D CCT E CCT F CCT G SUNRISE CCT H SWAN CCT I SABINO CANYON CCT J CP F ! ( CP G CCT K Aerial : 2008 Pima Association of Governments Topo : 2008 Pima Association of Governments ! ( CP D CP E Pima County Index Map CRAYCROF T ! (! ( Index Map Scale 1:5,250,000 The information depicted on this display is the result of digital analyses performed on a variety of databases provided and maintained by several governmental agencies. The accuracy of the information presented is limited to the collective accuracy of these databases on the date of the analysis. The Pima County Regional Flood Control Department makes no claims regarding the accuracy of the information depicted herein. CP B ! ( This product is subject to the Department of Transportation Technical Services Division's Use Restriction Agreement. Pima County Regional Flood Control District ALV E RN 1,000 500 0 RIVER ON CP A ! ( CLOUD 06/2010 \\gislib\rfcd\projects\imd\xavi\mxd\AKITSU\Craycroft\Craycroft_wash_Watershed_Fig1_1.mxd 1,000 Feet Figure 1.2 Study Limit Map Craycroft Wash Study Limit Study Limit CCT I CCT K CCT J Discharge Points River Proposed Floodplain Subbasins Existing Floodplain ZONE A ZONE AE ZONE X - SHADED ( ! SUNRISE CCT F SWAN CCT H CCT G CP F Aerial: 2008 Pima Arizona Government ( ! CP G ( ! CCT D CCT E CP D CP E CCT C KOLB !! ( ( CRAYCROFT CCT B Pima County Index Map CP B Study Limit Index Map Scale 1:5,250,000 ( ! OC AN YO N CCT A This product is subject to the Department of Transportation Technical Services Division's Use Restriction Agreement. Pima County Regional Flood Control District 1,000 500 0 CP A SA BIN RIVER The information depicted on this display is the result of digital analyses performed on a variety of databases provided and maintained by several governmental agencies. The accuracy of the information presented is limited to the collective accuracy of these databases on the date of the analysis. The Pima County Regional Flood Control Department makes no claims regarding the accuracy of the information depicted herein. ( ! CLOUD 06/2010 \\gislib\rfcd\projects\imd\xavi\mxd\AKITSU\Craycroft\Craycroft_wash_Watershed_Fig1_2.mxd 1,000 Feet Figure 1.3 Soil Classification Map Craycroft Wash Subbasins Soil Classification Soil Group: A (100%) Soil Group: B (100%) Soil Group: B (82%) C (18%) Soil Group: C (53%) D (47%) Soil Group: D (100%) CCT I SKYLINE KO LB CCT K CCT J Aerial: 2008 Pima Arizona Government SUNRISE CCT F SABINO CANYON CCT D CCT H CCT G CCT D CCT C Pima County Index Map RIV E R CRAYCROFT SWAN CCT B Index Map Scale 1:5,250,000 The information depicted on this display is the result of digital analyses performed on a variety of databases provided and maintained by several governmental agencies. The accuracy of the information presented is limited to the collective accuracy of these databases on the date of the analysis. The Pima County Regional Flood Control Department makes no claims regarding the accuracy of the information depicted herein. CCT A AL VE This product is subject to the Department of Transportation Technical Services Division's Use Restriction Agreement. COUNTRY CLUB RN ON Pima County Regional Flood Control District 1,000 500 0 CLOUD FORT LOWELL FORT LOWELL CAMP LOWELL 06/2010 \\gislib\rfcd\projects\imd\xavi\mxd\AKITSU\Craycroft\Craycroft_wash_Watershed_Fig1_3.mxd 1,000 Feet Section 2.0 Summary of Key Facts Section 2.1: General Information 2.1.1 Community: Pima County Regional Flood Control 2.1.2 Community Number: NFIP Community Number 04019C 2.1.3 County: Pima 2.1.4 State: Arizona 2.1.5 Date Study Accepted: Not Accepted 2.1.6 Study Contractor: Pima County Regional Flood Control District – Akitsu Kimoto 2.1.7 State Technical Reviewer: Not Applicable 2.1.8 Local Technical Reviewer: Suzanne Shields 2.1.9 River or Stream Name: Craycroft Wash 2.1.10 Reach Description: Craycroft Wash and tributary 2.1.11 Study Type: Hydrology and Hydraulics study of a Riverene System Section 2.2: Mapping Information 2.2.1 FIRM Panels: 04019C-1644, 1663 and 1665K 2.2.2 Mapping for Hydrologic Study: Lidar based on 2008 flight used to derive 2’ contour interval maps using ARC-GIS 9.3 2.2.3 Mapping for Hydraulic Study: Lidar based on 2008 flight used to derive a DEM (2-ft cell size) for use with GeoRAS Section 2.3: Hydrology 2.3.1 Model or Method Used: HEC-HMS (v. 3.4) model parameterized using methods of RFCD Draft Tech Policy 018 (October 10, 2008) 2.3.2 Storm Duration: 3-hr 2.3.3 Hydrograph Type: SCS Unit Hydrograph 2.3.4 Frequencies Determined: 100 yr 2.3.5 List of Gages used in Frequency Analysis or Calibration: None 2.3.6 Rainfall Amounts and Reference: SCS Type II, NOAA 14 Upper 90% Confidence Interval 2.3.7 Unique Conditions and Problems: None 2.3.8 Coordination of Q’s: Comparison with previous studies on file with RFCD and discharge estimates Section 2.4: Hydraulics 2.4.1 Model or Method Used: HEC-RAS 4.0, GeoRAS to parameterize 2.4.2 Regime: Modeled as subcritical 2.4.3 Frequencies for which Profiles were Computed: 100 yr 2.4.4 Method of Floodway Calculation: No Floodway 2.4.5 Unique Conditions and Problems: Boundary set at normal depth. Section 2.5: Additional Study Information: None. 9 Section 3: Survey and Mapping Information 3.1 Field Survey Information No field survey was used. 3.2 Mapping The 2008 Light Detection and Ranging (LiDAR) data was used for the analysis. Coordinates were in Pima County projection: Projection = State Plane, Arizona Central Zone Datum = NAD83 HARN Units = International Feet North American Vertical Datum of 1988 (NAVD, 1988) The LiDAR was used to derive a Digital Elevation Model (DEM) and a contour map. DEM derived on 5’ centers provided the basis for delineating the watershed and subbasins. DEM was also used to characterize the topography along channels used for the floodplain mapping process. Contour map derived from the DEM allowed modelers to visualize topographic differences in making decisions on how to model different areas. Section 4: Hydrology 4.1 Method description. For the floodplain mapping, a 100-yr discharge is required. The 100-year peak discharges for the sub-basins of the Craycroft Wash (CCT 1-10; Figure 3) were calculated using U.S. Army Corps of Engineers Computer Hydrologic Modeling System, (HEC-HMS) version 3.4. The HEC-HMS morel requires the parameters regarding rainfall, topography, soil, vegetation, and channel characteristics to determine runoff volume and peak discharge. Those parameters were determined according to the Pima County Regional Flood Control District Technical Policy 018 (Tech-018). Tech-018 is included in Appendix A. 4.2 Parameter estimation. Methods are summarized in Table 4.1. The data processing methods are summarized in Fig. 4.1. Table 4.1 - Methods used for a HEC-HMS analysis Rainfall Depth Rainfall Distribution Rainfall Loss Time of Concentration Transform Routing Selected Method NOAA 14, upper 90% Confidence Interval 3-hr SCS Type II Storm SCS Curve number SCS Segmental Method SCS Unit Hydrograph Modified-Puls 10 4.2.1 Drainage area boundaries. The limits of this study are shown in Fig.1.2. The study site includes Sections 1, 11-14, 23-25 of Township 13 South, Range 14 East, Sections 7 of Township 13 South, Range 15 East, and Sections 36 of Township 12 South, Range 14 East, Pima County, Arizona. Entire watershed of the Craycroft Wash is in FEMA Zone X, as shown on the current Flood Insurance Rate Map (FIRM) number 04019C-1644, 1663, and 1665K. The watershed is 3.16 square mile. The study watershed was divided into ten sub-basins while the study reach was divided into three segments (Fig.1.1). The upstream study limits are south of Sunrise Dr and south of Sunrise Dr (Fig.1.2). The downstream limit for the study is the confluence with the Rillito River. 4.2.2 Watershed work maps The boundary of the watershed and internal sub-basins were determined using Hydrology function in ArcGIS with DEM derived from the 2008 Lidar. Study reach includes a main channel and one tributary. The sub-basins reflected predominant topographic, soils, cover and development conditions, so that the sub-basins would represent hydrologic response from the sub-basin. The locations of the stream centerline, cross-sections, river banks, culverts, and other physical attributes of the wash were determined by using the 2-ft interval contour map and 2008 aerial photo. 11 Figure 4.1 – Flow Chart of Mapping Process Topographic Data Preparation using ArcGIS with TIN or DEM Hydrologic Analysis using PCHydro Geometric Data Preparation using ArcMap and Hec-GeoRAS (stream network, stream centerlines, cross sections, river banks, culverts, and/or block obstruction) Hydraulic Analysis using HEC-RAS (Manually input the following data; Manning’s nvalues, culvert data, expansion and contraction coefficients, normal depth boundary condition, ineffective flow areas, adjustment of reach length if necessary) Floodplain Delineation using HecGeoRAS 12 4.2.3 Gage Data. None Available 4.2.4 Statistical parameters None Available 4.2.5 Precipitation. Rainfall depth was selected from the NOAA 14 Upper 90% rainfall data used in PC Hydro. The point rainfall depth for the 3-hour storm was obtained, based on the coordinates of the centroid of the watershed (Latitude: 32.304, Longitude: 110.869). Areal reduction factor was applied to watersheds larger than 1 square mile as noted in Tech-018. The 3-hr, SCS Type II rainfall distribution described in Haan et al (1994) was used. 4.2.6 Physical parameters. A hydrologic soils group map for the study watershed is presented in Fig.1.3. Hydrologic Soil Group B is the dominant soil type in the Craycroft Wash watershed. The SCS Curve Number was determined using maps obtained from NRCS (http://soildatamart.nrcs.usda.gov/) as a basis for preparing a Hydrologic Soil Group Map for Pima County. The CN charts in the PC Hydro Manual (Arroyo Engineering, 2007) were the basis for CN selection. More than 99% of the study watershed is covered with Desert brush. A vegetation cover density of 25-30% was used to select the SCS Curve Number for the hydrologic calculation of the mountainous watersheds. Impervious cover percentage from 10-20%, were selected based on lot size, the fraction of the sub-basin that is developed and the tables in the PC Hydro manual. Sub-basin characteristics are summarized in Table 4.2 The detail of the CN calculation is included in Appendix D. 13 Table 4.2 - Sub-basin Characteristics Sub-Basin CCT A CCT B CCT C CCT D CCT E CCT F CCT G CCT H CCT I CCT J CCT K Area (sq mi) 0.11 0.15 0.54 0.07 0.04 0.32 0.16 0.57 0.63 0.27 0.3 CN 85.9 85.2 85.7 85.0 84.6 84.6 85.3 85.8 85.8 84.5 84.3 Impervious Area (%) 20.0 15.0 15.0 15.0 10.0 10.0 15.0 15.0 10.0 10.0 10.0 Vegetation Cover (%) 25 25 25 25 25 25 25 25 30 30 30 Lag Time (min) 11.3 12.0 26.7 10.0 5.6 14.5 10.6 20.0 18.0 13.5 14.7 The SCS TR-55 segmental Time of Concentration (Tc) method with a combination of kinematic wave method was used. The hydraulically most distant point on the sub-basin was identified. The length of sheetflow was estimated at 100’, the distance from the end of the sheetflow to a well-defined channel was selected as the shallow concentrated portion of the flow path, and the channel portion was the path from the well-defined channel to the sub-basin outlet was the ‘channel flow’ portion of the flow path. Tc is the sum of the travel time for sheetflow, shallow concentrated flow and channel flow. The travel time for sheetflow was calculated using kinematic wave method. The travel time for shallow concentrated flow was calculated using the methods described in the TR-55 manual (USDA-1986). The travel time for channels used estimates from a HEC-RAS model. The lag time was calculated as 0.6 Tc. The SCS unit hydrograph method was used to produce hydrographs at the outlet of the sub-basin in HEC-HMS. Runoff from sub-basins was routed using the Modified-Puls method. A storage discharge table for the channel routing was developed using the cross sections and slopes derived from HEC-HMS. Modified-Puls routing employed the methods described in the HMS manual. The detail of the calculation of the number of subreach is included in Appendix D. Sub-basin discharges are summarized on Table 4.3. 14 Table 4.3 - Sub-basin discharges Sub-Basin CCT A CCT B CCT C CCT D CCT E CCT F CCT G CCT H CCT I CCT J CCT K Area (sq mi) 0.11 0.15 0.54 0.07 0.04 0.32 0.16 0.57 0.63 0.27 0.3 Rainfall Depth (in) 3.34 3.34 3.34 3.34 3.34 3.34 3.34 3.34 3.34 3.34 3.34 Runoff Volume (in) 1.95 1.89 1.93 1.88 1.85 1.84 1.9 1.94 1.94 1.84 1.82 Peak Discharge (cfs) 258 331 739 168 114 624 377 959 1131 546 572 4.3 Problems encountered during the study. None 4.3.1 Special problems and solutions 4.3.2 Modeling warning and error messages The time interval of the rainfall data used in this study is 5 minutes, while the simulation time interval is 1 minute. The HEC-HMS model interpolated the 5-minute time interval of the rainfall data to 1-minute time interval. 4.4 Calibration. No Calibration 4.5 Final results. 4.5.1 Hydrologic analysis results The 100-year peak discharges at the concentration points along the Craycroft Wash were determined using the HEC-HMS. Six hours were simulated on a 1 minute time step with rainfall occurring in the first three hours. For the hydraulic analysis the following discharges were used: 15 Table 4.4 – Summary of 100-yr Peak Discharge Values Concentration Point Location CP A CP B CP D CP E CP F CP G Confluence with the Rillito River South of Rio Verde Vista Dr. North of Center Village Dr. North of Center Village Dr. South of Territory Dr. South of Territory Dr. Area (sq Rainfall Runoff Q100 Time to mile) Depth (in) Volume HMS (cfs) Peak (in) (hr:min) 3.16 3.04 1.65 3620 2:02 2.51 3.11 1.70 3145 1:58 1.02 3.24 1.82 1413 1:54 1.34 3.22 1.78 2093 1:47 0.95 3.34 1.91 1489 1:48 0.73 3.34 1.85 1269 1:44 Table 4.5 – Summary of 25-yr Peak Discharge Values Concentration Point Location CP A CP B CP D CP E CP F CP G Confluence with the Rillito River South of Rio Verde Vista Dr. North of Center Village Dr. North of Center Village Dr. South of Territory Dr. South of Territory Dr. Area (sq Rainfall Runoff mile) Depth (in) Volume (in) 3.16 2.37 1.1 2.51 2.42 1.13 1.02 2.53 1.02 1.34 2.50 1.19 0.95 2.60 1.28 0.73 2.60 1.23 Q25 HMS Q25 RRE (cfs) (cfs) 2244 1953 894 1333 954 807 1453 1272 734 871 701 590 Time to Peak (hr:min) 2:06 2:03 1:58 1:50 1:50 1:47 Table 4.6 – Summary of 500-yr Peak Discharge Values Concentration Point Location CP A CP B CP D CP E CP F CP G Confluence with the Rillito River South of Rio Verde Vista Dr. North of Center Village Dr. North of Center Village Dr. South of Territory Dr. South of Territory Dr. Area (sq Rainfall Runoff Q500 Time to mile) Depth (in) Volume HMS (cfs) Peak (in) (hr:min) 3.16 3.96 2.45 5679 1:59 2.51 4.04 2.51 4898 1:55 1.02 4.22 2.68 2178 1:50 1.34 4.18 2.63 3137 1:46 0.95 4.34 2.8 2230 1:46 0.73 4.34 2.73 1913 1:43 4.5.2 Verification of results. Results were compared with USGS Regression Equation 13 (RRE; Thomas et al, 1997) and regulatory discharge currently used (Table 4.7). The equation 13 results were generally lower than the HMS results, which would be expected, because these steep watersheds could be expected to produce higher than average discharge. The HMSderived peak discharge at CP A is lower than current regulatory discharge. Table 4.7 – Comparison of 100-yr Peak Discharge Values Concentration Point Location CP A CP B CP D CP E CP F CP G Confluence with the Rillito River South of Rio Verde Vista Dr. North of Center Village Dr. North of Center Village Dr. South of Territory Dr. South of Territory Dr. Area (sq Q100 Q100 mile) HMS (cfs) RRE (cfs) 3.16 2.51 1.02 1.34 0.95 0.73 3620 3145 1413 2093 1489 1269 2583 2254 1276 1526 1216 1016 Regulatory Discharge 4228 NA NA NA NA NA 16 Section 5: Hydraulics 5.1 Method description. Steady flow analysis was performed to determine 100-year water surface elevations in the study area by using HEC-RAS with the discharge obtained from HEC-HMS. 5.2 Work study maps As described above, geometric data for HEC-RAS including stream centerline, crosssections, and culverts were obtained from HEC-GeoRAS. The locations of cross sections and channels are show in Exhibit 1. The 100-yr and 500-yr floodplain limits are shown in Exhibit 1. 5.3 Parameter estimation. The watershed was modeled using methods consistent with District Tech Policy 019. 5.3.1 Roughness coefficients. Manning’s roughness coefficients for the channel and the over-bank areas were determined by using a 2008 aerial photo. The roughness used in this study is 0.045-0.06 for overbank areas and 0.035-0.045 for channels. Bank stations were refined by selecting bank stations based on the topography and a 2008 aerial photo. Differentiation of channel and overbank ‘n’ values should be done only when channel flow is at least twice as deep as overbank flow (Phillips and Tadayon, 2006). There are many reaches that are wide with several flow paths. Rather than assign a channel and overbank Manning’s n, an average n for the whole cross-section of 0.045 was assigned. 5.3.2 Expansion and contraction coefficients. Default HEC RAS expansion (0.3) and contraction (0.1) coefficients were used for the most cross sections. The expansion coefficient of 0.5 and contraction coefficient of 0.3 were used for the cross sections immediately upstream or downstream of culverts. 17 5.4 Cross section description. A 2-foot interval contour map derived from 2008 LiDAR data was used to select the location of cross sections. Cross-section locations were determined primarily based on the channel topography. The cross-section lines were drawn to be perpendicular to flow paths in Geo-RAS and ArcGIS. 5.5 Modeling considerations. 5.5.1 Hydraulic Jump and drop analysis. No Hydraulic Jumps were encountered. 5.5.2 Bridges and culverts. There are six culverts along the study reach of the Craycroft Wash. 5.5.3 Levees and dikes. None. 5.5.4 Islands and flow splits. There is an island at south of Camino del Celador. The house located immediately south of Camino del Celador is above the 100-year and 500-year flood water surface elevation, based on the HEC-RAS analysis in this study. The house was removed from a Craycroft Wash floodplain as an island. 5.5.5 Ineffective flow areas. Ineffective flow areas were noted on the study reach of the Craydroft Wash. In general these ineffective flow areas were disconnected overbank areas that would not convey flow to the next downstream cross-section or immediately upstream or downstream of culverts. 5.5.6 Supercritical flow. No supercritical reaches. 5.6 Floodway modeling No encroachment calculations were performed. 18 5.7 Problems encountered during the study. 5.7.1 Special problems and solutions. None. 5.7.2 Modeling warning and error messages. No errors occurred. The following warning messages occurred: Divided flow Energy loss greater than 1.0 foot Energy equation could not be balanced and defaulted to critical. Cross-section extended vertically. Multiple critical depths calculated. Conveyance ratio is less than 0.7 or greater than 1.4. Inspection indicated that the modeling is accurate given the steep channel conditions. Most of these errors force a critical solution which is reasonable for these steep watercourses. A summary of errors is available in Appendix E. 5.8 Calibration. None. 5.9 Final results. 5.9.1 Hydraulic analysis results. The HEC-RAS modeling results are included in Appendix E. 5.9.2 Verification of results. Existing floodplain maps are not available along the Craycroft Wash. The new map tends to follow the floodplain topography. The results suggest that the mapping is reasonable. Section 6: Erosion and Sediment Transport 6.1 Method description. None – not applicable 6.2 Parameter estimation. None – not applicable 6.4 Modeling considerations. None – not applicable 6.5 Problems encountered during the study. 19 6.5.1 Special problems and solutions. None – not applicable 6.5.2 Modeling warning and error messages. None – not applicable 6.6 Calibration. None – not applicable. 6.7 Final results. 6.7.1 Erosion and sediment transport analysis results. None – not applicable 6.7.2 Verification of results. None – not applicable Section 7: Ratio of the top width of 100-yr and 25-yr floodplain A map showing the cross sections with the ratio of 100-yr to 25-yr floodplain topwidth less than 1.25 and with the peak discharge greater than 2000 cfs is included in Addendum 1. An average ratio is 1.30 for the downstream main channel. The results indicate the downstream main channel is “confined”. 20 AI AK 9 " ) ççççççç çççç2çç6ç77 ç ç2ç6çç7çç2çç 72 ç2ç6çççç 66 3 ç2çççççç AD çç 17 ççççç 53 çç 26 ç ççççç çç AG " ) " ) ZONE X-SHADED " ) B " ) A D " ) A 16 " ) 18 çç2ç6ç48 çç ZONE X-SHADED Streets 3 çç çççç Proposed 100 year Floodplain FIRM XSection " ) ZONE AE " ) KOLB ROAD " ) 19 T T Proposed 100yr Floodplain LOMR Case Studies FIRM - Flood Insurance Rate Map " ) " ) " ) Floodways sections Jurisdictions Existing Floodplain Zone A AE 21 AO ZONE X " ) çççç2560 ççççç çççç2ç5ç55 ççç 2 çççç550 çççç ç S PIMA COUNTY )" Q P " ) X - (SHADED) ç25çç4çç6çç " ) R çç çççç2ç536 çç ççççç2531 ççççç X ççççç25çç26çç ççççççç2521 ççççç 1 25 ç çççç O " ) " ) N M ZONE X 6 çççç çç " ) ççç2ç5çç11 çç )" " ) L K " ççRIVER ) ççççççççç ROAD ZONE X-SHADED 251 0 J ç ççççççç ççççç30 ç ççççç2497 çççç " ) F " ) " ) 28 29 I G 94 24 çç ççççç 249çç0ç Pima County Index Map CLOUD ROAD " ) I ZONE X-SHADED ç M " ) " " ) ) " ) E D C çç2ç4ç8ç9 çç 2 ççç 0 25 çç2ç4çç8ç6ç A çç ççççç 249 9 çççç K " ) " ) TANQUE VERDE ROAD " ) TUCSON 33 O ç P " ) ZONE X ç TANQUE VERDE ROAD 05 04 " ) ççç2ç496 ççç 9 24 çççç çççç çççç çççç250 ççççç çççç çççççç2511 çççç7çççç çççç 25 çççç çççç çççç12 çççç çççç ç ç ç ç ç ç ç çççç çççç çççç2ç513 ççç ççç ççç Q 4 ç çç ç ç ç LOMR Case 99-09-130P Effective Date 7/24/2000 ç 32 ççç2ç500 ççç ççççç 2 ççç5ç02 çççç çççç çç L " ) N 31 06 çççç 03 25 " ) " ) çç2ç5ç05 ç B ççççççç 247 8 ZONE AE 248 2 247 6 2475 ççççççç 2470 F " ) ççççççç ççççççç ççççççç çççççç 2468 ç çç2ç476 ç ççç2ç4ç8ç0ç 24 çççççççççççç Base_Flood_Elev1 " ) " ) ") ) " ZONE A 23 " ) AB çç 8 ç ç 26ç3çççç çç263ç3ççççç ç ç26ç 28 ççççççç AA çç26çç23ççç ççç26ççç18çççç Z ççç2614 ççççççç 261 0 Y ççççççç ççç2ç6ç0ç5ççç Y ççç2ç6çç0ç0ç X ç ççç2ç5ç95 ççç W ççç2ç590 çç ççç2ç5ç85 ç çç V U çççç2ç580 çççç 25 çççç7ç5 ççççç çççç20 çççç ç 4 26 2496 13 C )" ZONE X 14 " ) 5 268 AF AH D SABINO CANYON " ) " ) " ) çç2720 ççççç2çççççççççççç ççççç271 çççççççççç ççççç ç2704 2700 ççççççç çççççç çç2696 ç çççç2703 ç ççççç9ç7 ç2ç6çç9ç2çç 26 ççç çç 0 27 AJ 09 AC ççç2 27 5 " ) AL SUNRISE ROAD ççç ç ç ç ç çç ççççççççççç çç2732 ç 20 27 ççç çç Exhibit 2.1 Annotated Flood Insurance Rate Map 04019C1665 K Craycroft Wash CORONADO NATIONAL FOREST " ) 42 27 A )" M 07 12 ççç " ) çç2ç7ç63 AN 2746 çç2ç6ç8ç7 ç çç çç2ç6ç8ç2ççç çççç2ç6ç77 ççç çç2ç6ç72 ç ç " ) 11 ç2752 çççç ççççç 274 0 E çççç 08ççççç çççç çççççççç ç 4 277 7 0 27 ç The information depicted on this display is the result of digital analyses performed on a variety of databases provided and maintained by several governmental agencies. The accuracy of the information presented is limited to the collective accuracy of these databases on the date of the analysis. The Pima County Department of Transportation Technical Services Division makes no claims regarding the accuracy of the information depicted herein. This product is subject to the Department of Transportation Technical Services Division's Disclaimer and Use Restrictions. 1,000 500 0 Pima County Regional Flood Control 97 East Congress Street - 3rd Floor Tucson. Arizona 85701-1207 (520)243-1800 - FAX (520)243-1821 http://www.rfcd.pima.gov gislib\rfcd\projects\imd\xavi\mdx\AKITSU\Craycroft\Craycroft_Exh2_1Anno_FIRM28x40_1665K.mxd 1,000 Feet Exhibit 2.2 Annotated Flood Insurance Rate Map 04019C1645 K Craycroft Wash WIL 19 ZONE X C ITA EV ZONE X RED 24ç4ç ç 6 çççç ççç ç FE E F 36 çç çç ç I SO L W ES T FIESTA DEL 30 2 3 ç ç ç ç ç4ç ç5 ç ççç çç ç ç ç ç ç ç ç ç ç çç çççç ççç ç ççç çççç ç ç ç ç ç ç ç ç çç H " ) çççç ççç ççç ççç çç ççç ççççç ç ç ç ç ç ç ç 244 9 ç ç çççççç ççççççç çç ç ç ç ç ç " ) F 244 7 2 4 ç ç ç ç ç2 ç ç 43 çç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç çç ç ç ç çççççç ç ç ç ç ç ç 244 5 ç ç ç ç ç ç ç ç çç çççççç çç G 4 ç ç ç ç4 ç ç ç ç ç2ç çççççç ç çççç E " ) ZONE X - SHADED SA NTA " ) " ) " ) ççç ç ççç ççç çççç ç çç çç çç çç ççç ç çç ç D " ) çç ç ç ç ç ç ç ç ç ç ç ç ç2ç 43 çç çççç çççç çç çç ç 8 çççç ççççç ç ç ç çç çç çç çç çç ç 2 4 3 9 ç çç ç çç ç ç ç ç ç ç ç ç ç ç ç ç ç ç244 1 ç çç ç çç ççççç ç çç ç ç ç ççç 2 çç çç ççççç çç ç çç ç ç ç 44 çç ç ç ç ç ç çç ççç 0 çç çç çç ç ççç ç çç ç ç ç ç ç çç ç ççç ççç ç ç çç ç ç çç C çç ç ç ç ç çç ç ç ç çç ç çç çç ç ç çç 2434 çç çç çç çç çç ç çç çççççç ç ç çç ç ZONE AE çç ç ç ç çç ç çç ç ç ç ç ç çç çççççç çç ç ççç TUCSON çç ç ç çç ççç LOMR Case 05-09-A090P Effective Date 7/6/2006 çç ççççç ç ç ç ç ç ç ç ç ç ç ç ç ç çç O ççç ççç ççç çç ççç çç çç ççç çç çç ççç çç çççç RIV ER PIMA COUNTY RI çç ç ç ç ç ç ç ç ç ç ç ç ç ç ç Pima County Regional Flood Control 97 East Congress Street - 3rd Floor Tucson. Arizona 85701-1207 (520)243-1800 - FAX (520)243-1821 http://www.rfcd.pima.gov ZONE X ZONE A SA B çç ççç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç ç çç ç ç çç ç ç This product is subject to the Department of Transportation Technical Services Division's Disclaimer and Use Restrictions. N STIA N 25 RO " ) çç ç çç ç ççç ç The information depicted on this display is the result of digital analyses performed on a variety of databases provided and maintained by several governmental agencies. The accuracy of the information presented is limited to the collective accuracy of these databases on the date of the analysis. The Pima County Department of Transportation Technical Services Division makes no claims regarding the accuracy of the information depicted herein. HA WK SN ES INA T L RD S E BA E LL CA LOMR Case 4/09/0465X Effective Date 4/22/2004 35 CA SA N VILL A MES A CRAY CROFT 26 SU TA NUR ED AL L AT E E ER G RD RIV VI S VE Proposed 100 year Floodplain RI O VE TA D RD E VI EL ST A AC IMA MO T 24 23 31 Case 99-09-1302P ZONE X LOMR Effective Date 7/24/2000 0 330 660 Streets FIRM X-Sections 1,320 Feet ç ç ç ç ç Base Flood Elevations Proposed Floodplain LOMRs FIRM - Flood Insurance Rate Map Sections Jurisdictions Existing Floodplain Zone A AE AO X X (SHADED) Pima County Index Map gislib\rfcd\projects\imd\xavi\mdx\AKITSU\Craycroft\Craycroft_Exh2_2Anno_FIRM8X11_1645K.mxd Exhibit 2.3 Annotated Flood Insurance Rate Map 04019C1644 K Craycroft Wash 22 I ANC LE CAL BE " ) ECA IO FO R E Proposed 100 year Floodplain PIMA COUNTY " ) BI BH BG " ) HILL FARM 12 ç ç ç ç41 4 ç çç ç ç ççç çç 11 24 çç çç 2 24 çç çç ççç çç ççç çç TUCSON H ZONE X-SHADED LO W CR EE K ç çç 0 Streets FIRM X-Sections çç WIL çç ç çç This product is subject to the Department of Transportation Technical Services Division's Disclaimer and Use Restrictions. ASA CARR HIL L RA NC ç ç çç ç The information depicted on this display is the result of digital analyses performed on a variety of databases provided and maintained by several governmental agencies. The accuracy of the information presented is limited to the collective accuracy of these databases on the date of the analysis. The Pima County Department of Transportation Technical Services Division makes no claims regarding the accuracy of the information depicted herein. ç LOMR Case 00-09-0616P Effective Date 7/26/2000 8 2ç4ç ç 2 ççççç PARADE GROUND ç ZONE AE 24 2ç4 ç ç ç ç ç çç ç ççç çç çç 34 2420 ç ççç LOMR Case 04-09-0621P Effective Date 11/4/2004 CAMP LOWELL çç ç ç ç ç ç ç ç ç ç çç ççç ç ççç 2414 LOMR Case 04-09-0465X Effective Date 4/22/2004 ZONE A 35 " ) BF " ) 0 241 OA çç ç ç çç ç ç ç çç ç ç ç ç ç ç çç çç ç ç ç ç ç ç çç ç ç ççç çç çç çççççççççç ç ç ç ç çççççç SWAN ç çç ç ç ç ç çç ç ç ç çç ç ç ç ç ç çç LOMR Case 04-09-0465X Effective Date 4/22/2004 ZONE X-SHADED ç ç çç ç ç çççç çç KB RIVER HOUSE ççç ççç ççç ççç ç ç ç2ç 40 çç ç ç 5 Y ç ç çç çç ç ç çççç CAMINO LA JICARRIL LA çççç ç 26 çççç ç ç çç ç çç ç C HU TA AR ZONE AE ç çç çç ç çç UR SO 241 7 ççç ç çççç ç ççç NO A HU C EC A ççç ç ççç MI UO ççç çç çç ççç ç çç BD " ) LL EC SIN CAMINO BL ANCO ON CA CI A PL S CA ST P A RK LE C ANA ZONE A Pima County Regional Flood Control 97 East Congress Street - 3rd Floor Tucson. Arizona 85701-1207 (520)243-1800 - FAX (520)243-1821 http://www.rfcd.pima.gov ZONE X CAL CAL LE PERDIZ VE LL VIA A ZONE X 27 23 RIV ER 260 520 1,040 Feet ç ç ç çç Base Flood Elevations Proposed Floodplain LOMRs FIRM - Flood Insurance Rate Map Sections Jurisdictions Existing Floodplain Zone A Pima County Index Map AE AO X X (SHADED) gislib\rfcd\projects\imd\xavi\mdx\AKITSU\Craycroft\Craycroft_Exh2_3Anno_FIRM8X11_1644K.mxd Appendix C: Survey Field Notes Addendum