Merrick & Co 20180520 LAS data Clark County Aerial LiDAR Project Clark County Aerial LiDAR Project Greenwood Village, CO Merrick & Co. LiDAR terrain mapping to the SNWA for five (5) non-contiguous project areas within Clark County, Nevada. SNWA will utilize the final deliverables to assist with managing the region's water resources and develop solutions that will ensure adequate future water supplies for the Las Vegas Valley. The Desert Conservation Program (DCP) is contributing funds to SNWA for specific Scope Of Work (SOW) tasks and deliverables. Base Specification 1.2 with a Nominal Point Spacing (NPS) of 0.7m for QL2 data. LiDAR terrain mapping to the SNWA for five (5) non-contiguous project areas within Clark County, Nevada. SNWA will utilize the final deliverables to assist with managing the region's water resources and develop solutions that will ensure adequate future water supplies for the Las Vegas Valley. The Desert Conservation Program (DCP) is contributing funds to SNWA for specific Scope Of Work (SOW) tasks and deliverables. Project Area: 289.74 square miles total QL2 data Deliverabes: LAS 1.4 Raw Swath's Classification of the LiDAR point cloud in accordance with the following classification scheme: Class 1 = Processed, but Unclassified Class 2 = Bare-earth Ground Class 7 = Low point (noise) Class 9 = Water Class 10 = ignored ground (near a Breaklines) Class 17 = Bridges Decks Class 18 = High Noise DEM rasters GeoTiff (.tif) QL2 = two-foot raster using Hydro Conditioned and Hydro Flattened breaklines and ground classified lidar points Breaklines are delivered in ESRI file geodatabase feature class. Lakes larger than 2 square acres and rivers greater than 100 feet wide. Tiles are based on section format. USGS NGP Base Specification v1.4 Optech Galaxy Airborne Laser Terrain Mappers (ALTM) SN5060385 8 0.7 2 0.7 2 1950 170 40 64 300 3.5 1.05 1064 1 0.25 1419 20 NAD_1983_2011_StatePlane_Nevada_East_FIPS_2701_Ft_US National Geodetic Survey (NGS) Geoid12B 0.36 0.088 36 0.061 36 0.230 39 1.4 6 Withheld (ignore) points were identified in these files using the standard LAS Withheld bit. Swath "overage" points were not identified in these files by a separate bit flag. 12-bit 1 Undetermined/Unclassifed 2 Ground 7 Low point (noise) 9 Water 10 Ignore ground (near a breakline) 17 Bridge Decks 18 High Noise 20180413 20180417 ground condition Complete Unknown -114.978950 -113.997449 36.868273 34.972156 none DEM LIDAR Breaklines none Clark Co Nevada none 2018 Unknown Unknown Craig Hale Las Vegas Valley Water District / Southern Nevada Water Authority Spatial Technologies Project Manager mailing and physical address

100 City Parkway Suite 700

Las Vegas NV 89106 702-862-3730 craig.hale@snwa.com Microsoft Windows Vista Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 9.3.1.4095 Verification of attribute accuracy for LiDAR data involves the use of filtering techniques. Auto-filtering uses algorithms to reclassify data in the point cloud. Hand-filtering involves the analysis of a technician working in a graphic environment to reclassify the erroneous points that may remain in the LiDAR point cloud after auto-filter. Calibrations of the LiDAR flightline data are performed; this process is known as boresighting. The flightlines are compared to evaluate both their relative and absolute accuracies. The dataset was reviewed to ensure completeness and accuracy. This data set was produced to meet ASPRS Positional Accuracy Standards for Digital Geospatial Data (2014) for a 21.0cm RMSEx / RMSEy Horizontal Accuracy Class which equates to Positional Horizontal Accuracy = +/- 36.35cm at a 95% confidence level. This data set was tested to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class. Actual NVA accuracy was found to be RMSEz = 4.508cm, equating to +/- 8.836cm at the 95% confidence level. Actual VVA accuracy was found to be +/-23.004cm at the 95th percentile. Thirty-six (36) NVA check points and thirty-nine (39) VVA check points were used. .061 The NVA was tested using 36 independent survey checkpoints located in open terrain areas. The checkpoints were distributed throughout the project area. Elevations interpolated from the DEM surface were compared to the elevation values from the surveyed checkpoints. The RMSEz was computed to be 3.1cm and the Accuracyz to be +/- 6.1cm at the 95% confidence level. This meets the required Accuracyz value of 19.6cm or better at the 95% confidence level. The VVA was tested with using 39 independent survey checkpoints located in vegetated terrain. The checkpoints were distributed throughout the project area. Elevations interpolated from the DEM surface were compared to the elevation values from the surveyed checkpoints. Actual VVA accuracy was found to be +/-23.0cm at the 95th percentile. This meets the required Accuracyz value of 29.4cm or better at the 95th percentile. Merrick & Co 20180520 spreadsheet LIDAR check points LIDAR check points Las Vegas, NV SNWA 1200 disc 2018 ground condition LIDAR check points 36 NVA and 39 VVA check points were used Merrick & Co 20180520 LAS data LIDAR LIDAR Greenwood Village, CO Merrick & Co 1200 disc 20180413 20180417 ground condition LIDAR ASPRS LAS 1.4 QL2 specifications, two points per square meter. LiDAR pre-processing: Relative carrier phase positioning and Kalman filtering of the airborne GNSS - inertial data was done for each mission (flight) to establish the proper reference frame and remove satellite and receiver clock biases occurring at the airborne GNSS receiver. The result of this process was a Smoothed Best Estimate Trajectory (SBET) file. The SBET, ranging, and scanner data were synchronized in the LiDAR point cloud creation software and point cloud data was created for each swath as LAS files. LiDAR calibration technicians analyzed and refined the boresight values for each mission. Once refined, all project data was processed through a least-squares bundle adjustment to average minor calibration error inherent in the SBET. This post-adjusted LiDAR data was analyzed for both relative and absolute accuracy and found to be within project specifications. 20180520 09035700 Doug Jacoby Merrick & Co Project Manager mailing and physical address

5970 Greenwood Plaza Blvd.

Greenwood Village CO 80111 303-353-3903 doug.jacoby@merrick.com Classified LAS 1.4: LIDAR data was collected using Optech Galaxy sensor. The raw data was verified in MARS software for complete coverage of the project area, and boresighted to align the flightlines. Raw data files were parsed into manageable client-specific tiles. These tiles were then processed through automated filtering that separates the data into different classification groups: unclassified points, ground points, low noise, water, ignored ground, bridge decks and high noise. The data was next taken into MARS to reclassify the erroneous points that may remain in the LIDAR point cloud after auto filter. Two points per square meter (QL2). 20180520 Doug Jacoby Merrick & Co Project Manager mailing and physical address

5970 Greenwood Plaza Blvd

Greenwood Village Co 80111 303-353-3903 doug.jacoby@merrick.com Breaklines: Using MARS software Hydro breaklines are captured (ESRI .shp file): Rivers greater than 100 feet wide and water bodies larger than 2 acres. Monotonicity is verified (hydro moving in a downstream direction). 20180520 Doug Jacoby Merrick & Co Project Manager mailing and physical address

5970 Greenwood Plaza Blvd

Greenwood Village CO 80111 303-353-3903 doug.jacoby@merrick.com DEM (QL2) two foot cell size Using MARS software GeoTiff (.tif) files are created with a two-foot (QL2) cell size. The ground classified LIDAR points plus the hydro breaklines are used to create these files. The breaklines are rivers greater than 100 feet wide and waterbodies larger than 2 square acres in size. The tiles are delivered in section format. 20180520 Doug jacoby Merrick & Co Project Manager mailing and physical address

5970 Greenwood Plaza Blvd

Greenwood Village Co 80111 303-353-3903 doug.jacoby@merrick.com Point point 1 State Plane Coordinate System 1983 2701 0.9996 -99.000000 0.000000 500000 0 coordinate pair 0.001 0.001 survey feet North American Datum of 1983 (2011) Geodetic Reference System 80 6378137.000000 298.257222 North American Vertical Datum of 1988 Geoid12B 0.001 feet Explicit elevation coordinate included with horizontal coordinates Clark County Aerial LiDAR Project Clark County Aerial LiDAR Project Merrick & Co ASPRS LAS 1.4: 1 = Unclassified 2 = Ground 7 = Low noise 9 = Water 10 = Ignore ground 17 = Bridge decks 18 = High noise ASPRS LAS 1.4: 1 = Unclassified 2 = Ground 7 = Low noise 9 = Water 10 = Ignore ground 17 = Bridge decks 18 = High noise Doug Jacoby Merrick & Co Project Manager mailing and physical address

5970 Greenwood Plaza Blvd.

Greenwood Village CO 80111 303-353-3903 doug.jacoby@merrick.com Unknown 20180520 Merrick & Co Doug Jacoby Project Manager REQUIRED: The mailing and/or physical address for the organization or individual. REQUIRED: The city of the address. REQUIRED: The state or province of the address. REQUIRED: The ZIP or other postal code of the address. 303-353-3903 doug.jacoby@merrick.com FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time