Project Level Watershed Analysis McBride Springs Campground ...

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Vegetation (Riparian Areas) root disease fungi is prevalent in the white fir component with mortality across size classes. Understory vegetation includes manzanita and white thorn. Willow, elderberry, thimbleberry, gooseberry, sedges and grasses. Project Level Watershed Analysis McBride Springs Campground Diseased Trees Removal Project Very limited riparian area occurs upslope from the urban area while extensive wetlands dominate the lower portion of the watershed including within well-developed areas in the city of Mount Shasta. Table 1: Watershed characteristics for the Project area and the Project Level Analysis Watershed. Hydrologic Location: McBride Campground lies on the western flanks of Mount Shasta within a 7 th field hydrologic unit, McBride Springs (18020005010302). The McBride Springs watershed is tributary to Cascade Gulch-Mount Shasta (6 th field), Box Canyon (5 th field) and Sacramento Headwaters (4 th field) hydrologic units. The scale selected for this PLWA is based on the smallest watershed that has readily available information that addresses the proposed activity. Analysis of a larger watershed may not detect any effects from the proposed activities; analysis of a watershed area smaller than the 8th field HUC may magnify any effects. Chapter 2: Issues and Key Questions Issue: Effects of the proposed activities on riparian habitat and Aquatic Conservation Strategy objectives. Key Questions: Are the proposed activities consistent with the Aquatic Conservation Strategy (ACS) objectives? How will proposed activities affect the Aquatic Conservation Strategy and the condition of Riparian Reserves in the analysis watershed? How will the activities proposed in and adjacent to the McBride Springs Riparian Reserve affect habitat in the Riparian Reserves at this site? Chapter 3: Current Conditions The purpose of Chapter 3 is to provide a general description of current conditions for aquatic, terrestrial and human uses in the project area. Only information relevant to the issues and key questions is presented. Climate
The project area is located in the extreme northern end of the Mediterranean Highland Climate Region and is characterized by warm dry summers and cool wet winters. Annual precipitation in the project area is estimated to be approximately 66 inches with the majority of this precipitation falling as snow. Additionally, Mt. Shasta provides a strong orographic influence upon storms approaching from the southeast and creates a deeper snowpack in the vicinity. Thunderstorms produce occasional summer precipitation events. The project area lies between 4,480 and 5000 feet in elevation with south-westerly aspect. A disturbance climatic regime is strongly influenced by the location of the project on the flanks of Mount Shasta at 14,179 feet summit elevation. Geology and Geomorphology Mount Shasta is a stratovolcano with a history of eruptive episodes of lava and pyroclastic flows. Individual lava flows stand out as buttes on the more gentle flanks of Mount Shasta immediately above the project area and form the steep ridges in the watershed analysis area. Deposits of glacial outwash material lie on and adjacent to rock outcrops and fill the very steep drainages. The dominant processes occurring today within the watershed that affect the human environment include rockfall, debris flow and avalanches. The history of debris flow in the 7th field watershed is recent: in 1997 a rain on snow event, with a 100 year recurrence interval, initiated a debris flow in the drainage east of Cascade Gulch activating 2.5 miles of glacial outwash material that reached the city limits. Hydrology and Riparian Reserves Springs and channels occur in the project area and flow intermittently. Although snowmelt and groundwater recharge occurs earlier in the spring, groundwater activates the springs and flow occurs in the summer. During these periods of surface flow, soils become saturated and overland flow occurs below the springs and upslope of the campsites making some campsites unsuitable for camping. Small drainage ditches can be seen upslope of several campsites from past efforts to control and intercept overland flow before reaching individual campsites. The current management practice is to protect soils by closing wet campsites until they dry out. The riparian reserve within the McBride Springs Campground project area maintains facultative and obligate riparian vegetation with limited water from the spring source and short duration flow in the intermittent stream. The intermittent stream carries annual surface water from the spring down slope through the campground and downstream of the project area. This occurs primarily in the months of July and August when snowmelt recharges the groundwater and allows surface flow to occur. It is not known how far this flow continues down slope; however there is evidence of scouring due to runoff in the road crossings of Cascade Gulch. The intermittent stream stemming from McBride Springs is the only known intermittent stream that conveys this annual water in the upper reaches of this watershed or supports riparian vegetation. Most of the intermittent streams in the watershed have such high infiltration that they infrequently convey water; when they do they function to maintain important connectivity for terrestrial and aquatic organisms. Other intermittent streams function to deliver large sediment loads to the reaches at lower elevations and have no riparian vegetation associated with them. Maintaining the integrity of these channel features is important to Project Level Watershed Analysis McBride Springs Campground Diseased Trees Removal Project
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Project Level Watershed Analysis McBride Springs Campground ...

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