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Springs There aze two different types of springs within the permit area: Springs in Surficial Sediments - Groundwater that moves through sediments that have a limited thickness and aze generally considered to be unconsolidated (i.e., alluvial, mantle cover, and landslide deposits). Subsurface water moving through the alluvium emerges as a spring, and dischazges into the drainage channel. Colluvial groundwater moving down-gradient emerges from the colluvium as a spring. The source of the groundwater in the colluvium can be snowmelt infiltration, rainfall infiltration, dischazge from a surface channel or upgradient bedrock spring flows that infiltrate into the colluvium. Bedrock Springs -Springs can be encountered where subsurface formations outcrop. Groundwater moves along the surface of the formation and eventually daylights. Since 1978, dischazge rate data have been collected from 83 springs. Available data indicate that approximately two-thirds originate from surficial sediments and one-third have bedrock formations as their source. The locations of all springs aze shown on Map 37. The currently monitored springs are shown on Map 34. Spring flow data are presented in Annual Hydrology Reports and aze summarized in Table 16. • Although dischazge data from alluvial springs aze limited, it is appazent that they aze highly sensitive to seasonal variations. There is also a wide variation in flow from alluvial springs during the yeaz. This large variation suggests that: 1) The capability of the alluvial sediments to transmit water is great, 2) The storage volume of the alluvial sediments is small relative to the rechazge and discharge rates, and 3) The alluvial sediments aze in good connection with surface water flows. The overall storage capacities of alluvial spring groundwater systems aze lazge. Mantle cover springs also display lazge seasonal dischazge variations. These springs have very high springtime flow dischazge rates, but commonly cease flowing entirely during the fall and winter months. This suggests that, like the alluvial groundwater system, the mantle cover groundwater systems have an appreciable capacity to transmit water, but that the storage volumes of these systems aze small relative to the rechazge and discharge rates. The North Fork Valley has a long history of slope instability (Dames & Moore, 1993). One of the results of unstable slopes is landslides. A common result of some landslides is a change in surface water expression, or the relocation of springs. During the 1993 field investigation, for example, two previously identified springs in the Jumbo Mountain azea, Raymond Wilcox Reservoir No. 2 and Jumbo Spring No. 7 Pond, were not located, and one new spring, Section 24 Spring No. 1 Pond, was discovered. It is probable that flow in these springs was altered due to landslides. The combined total volume of water dischazged from the landslide springs is nearly twice that of any rock units in the mine area. Landslide deposit springs are highly influenced by seasonal variations in precipitation. Thus, the travel times from the recharge azea to spring dischazge 2,04-7 $ Revised November 1004 PRI G