Maps of the Watershed Yuba River Watershed South Yuba River Watershed Watershed 1 Monitoring Sites 5 Land Cover 8 Parcel Density 2 Topology & Hydrology 6 Land Use 9 Road Density 3 Public Ownership 7 Parcels 10 Slope 4 Aerial Photography Prepared by the South Yuba River Citizens League and Watershed GIS Services Funded by the Department of Conservation and the Targeted Watershed Initiative Program, Sierra Water Trust Project (a collaborative agreement between American Rivers and the Natural Heritage Institute funded by the U.S. Environmental Protection Agency)
Watershed Monitoring Sites Map 1 ( 31 S. Yuba Riv er 19 ( ( 35 Nishinam Soggy Dawg. Rush Crk Way Dry Gulch ( 36 Lowden Lane Below Crooked Arrow Ln Hwy 49 Newtown Rd John Barleycorn 5 SYRCL Water Quality Monitoring Program has two sites on established in 2005, one at the end of just before the confluence with South Yuba, and one is mid way along. The program also monitors water quality at sites on the South Yuba River above and below the confluence. Eight staff plate gauges were installed in May 2011, to monitor water elevation changes and the date at which the stream became dry. Four staff gauges are on and four are on tributaries.. Flow Gauge Staff Plate Gauge ( Citizen Water Quality Monitoring Site
Watershed Topology & Hydrology i ve ) anal rc r il Tra ce (Old ipeline R o a Exc els i Yu b In d ep La ke Ve r ap ende n S. Map 2 Ce m k Red H i al Can ter Les Ne w Re tow sv. n Ne w De nc an al e r Cr e ek The natural drainage of the land is what determines the watershed boundary, and precipitation runoff within the watershed eventually drains to the confluence of with the South Yuba River. Additional water is added to the system from NID in the form of irrigation water (from the Red Hill Canal and Newtown Canal), as well as piped treated water to the properties in the headwaters of the watershed. A total of 53 ponds were identified, 7 of which were within 150 feet of a blue line stream found on the USGS topo. In summer 2011, NID substantially increased their service area for piped treated water in the vicinity of and including much of the northern watershed. Topology from USGS 7.5' Topology Quads. Diversion Dam data from the California State Water Resources Control Board. 0 l 49 «o wt 5 ll Cana anal Bu ffingt Can on al Rush Cree ent H ill C 0.5 1 2 # Diversion Dam NID Canal System Lake or Pond NID Treated Water Service Date Service Started 1996 1998 2007-2008 2011
Tasha Rd D Peaceful Valley Rd Watershed Public Ownership Map 3 Lake Vera Purdon Rd Jones Bar Rd Bodie Ridge Rd Indian Shack Rd Augustine Rd Excelsior Ditch Camp Rd Borrelli Rd Cedarsong Rd iamond Oaks Dr Sunrock Rd Gochine Dr Yuba Crest Dr N ishinam Gulch Rd John Barleycorn Rd Fox Hill Rd Ragon Rd Foster Rd Tower Hill Rd Airport Rd Owl Creek Rd Newtown Rd Indian Flat Rd Wet Hill Rd Oak Creek Dr Monte Vista Dr Beckville Rd Moon Valley Rd B Champion Mine Rd More than 90% of watershed is privately owned. The South Yuba State Park (California State Parks) near the confluence of is 5% of the watershed. The Bureau of Land Management owns scattered parcels near the watershed ridge. Nevada City owns land off Airport Rd at the headwaters and along Indian Flat Rd & Indian Trail. Nevada County recently purchased land on Hwy 49 near the watershed headwaters. A total of 21 gold mine sites, which may pose risk to water quality, were mapped from available data. Mine sites from USGS Mineral Resource Data System (MRDS). MRDS is a collection of reports describing metallic and nonmetallic mineral resources Cedro Rd American Hill Rd Providence Mine Rd Old Downieville Hwy Reward Nevada County Nevada City California Department of Parks and Recreation Bureau of Land Management Private
Watershed Aerial Photography 2010 Map 4 Aerial photography provides an unprocessed view of land cover. Development and agriculture can be seen in the middle of the watershed, just to the north of Hwy 49, and to the west of Nishinam Gulch.The area near the confluence with the South Yuba River, including State Park land, shows the least disturbance From the National Agriculture Imagery Program (NAIP). Image captured on 7/13/2010 at 2pm.
Watershed Land Cover Map 5 Land cover is an important factor in understanding how a watershed functions and has been analyzed using satellite imagery with some ground truthing. Vegetation classes have different implications for habitat and interactions with rainfall. Changes to land cover over time can be analyzed as responses to land use or climate changes. As of 2006, watershed was 80% forested, 10% shrub, 7% grass/herbaceous and 4% developed. From USGS National Land Cover Database (NLCD). Land cover interpreted fromtm Landsat satellite data (an update from 2001 land cover data). Dataset resolution is 30 meter pixels. _Landcover Developed, Low Intensity Developed, Open Evergreen Forest Deciduous Forest Mixed Forest Shrub/Scrub Grassland/Herbaceous Open Water
Waterhed Land Use Map 6 Land use differs from land cover in that the spectrally defined classifications of satellite imagery were designed to inform human use, rather than just cover. For example, an herbaceous/grass land cover class can be found in grassland, agriculture, residential and corporate parks. This helps to evaluate various potential impacts to the watershed. As of 2000, the watershed was 86% forested, 13% rangeland, and 1% was classified as built-up. or agriculture. From CalVeg: Produced by the California Department of Forestry and Fire Protection and the USDA Forest Service. Baseline Data Agricultural land Barren land Forest land Rangeland Urban or Built-up land Water
Watershed Parcels Map 7 Parcel sizes give a sense of of habitat fragmentation and development, land use intensity and percent impermeable surfaces (which tends to run water away rather than supplying the local vegetation and ground water). A total of 438 parcels in the watershed range in size from 0.1 acres, in Eden Ranch, to the 187 acres, in the John Woolman School. The median parcel size is 4.7 acres. Just over half of these parcels claimed a homeowners exemption in 2009. This exemption indicates the parcel is owned by those living on site and not elsewhere. Parcels boundaries from Nevada County, Feb 2011. Parcel Boundary State Highway
Watershed Parcel Density Map 8 Parcel density is used to show patterns of development and help evaluate how intensively the land is used. In most watersheds, the headwaters are less intensively developed than lower elevation areas. shows the reverse trend, with the higher parcel densities tending towards to top of the watershed. This may have implications for water quality and the availability of stream flow in mid-watershed channels. Parcel data from the Nevada County GIS department. A GIS point density process was run using the center point of each parcel. The process calculates the # of parcels within a quarter mile radius around each point. 10 classes were created, using the Jenks natural breaks classification method. Parcel Density Class 1 2 3 4 5 6 7 8 9 10
Peaceful Valley Rd Watershed Road Density Map 9 Lake Vera Purdon Rd Jones Bar Rd Bodie Ridge Rd Indian Shack Rd Augustine Rd Excelsior Ditch Camp Rd Skyranch Pl Borrelli Rd Cedarsong Rd Diamond Oaks Dr Sunrock Rd Gochine Dr Tower Hill Rd Airport Rd Yuba Crest Dr Owl Creek Rd Weeping Willow Way Oak Creek Dr Tasha Rd Nishinam Gulch Rd Woolman Ln Queen Elizabeth Way Fenton Way Toller Ridge Ct Monte Vista Dr Way Monte Vista Dr Colombine Ct Lowden Ln Carli Way Crooked Arrow Ln Prince R a nier Way Newtown Rd Champion Mine Rd Road density gives a sense of landscape fragmentation and impact to habitats. Roads can impede animal movement, and disrupt natural hydrology. Road density also helps understand the potential for impacts from road surface erosion, drainage, and sediment delivery to streams. Based on data that unfortunately omits driveways and some private roads, the average density in the watershed is 3.4 roads per sq mile and the maximum is 5.8 roads per sq mile. Roads data from USGS. A GIS analysis process was run using line density for South Yuba Watershed Roads. The process calculates a magnitude per square mile from the line features that fall within a mile radius around each cell. Beckville Rd John Barleycorn Rd Moon Valley Rd Cavanaugh Ln Country Cir Merryhill Way Indian Flat Rd Eden Ranch Rd Fox Hill Rd Ragon R d Roads/ Sq Mile 1.3 2 Cedro Rd 3 Lake or Pond Foster Rd American Hill Rd ovidence ne Rd 4 Airport Rd Wet Hill Rd Old Downieville Hwy 5 5.8 B Reward
Watershed Slope Map 10 Slope gives an overall indication of how rugged the watershed is. It can also be a helpful variable in calculating erosion, stability, water infiltration and cost to develop. The watershed is very similar to other watersheds in this same elevation range in the South Yuba. About a third of the watershed has 10-20% slope, a quarter of the watershed has 20-30% and about a fifth is over 30% slope. Slopes were derived from a USGS 10 meter Digital Elevation Model. Slope Class 0-5% 5-10% 10-20% 20-30% > 30%