watervulnerability

Recommendations

Info

Chugach National Forest Watershed Vulnerability Assessment, Alaska Region (R10) avalanches, and exposure of glacial moraines could lead to higher bedload transport and channel shifts in depositional areas. This deposition, however, is seen as a natural response and does not pose risks to infrastructure or other values. Some forms of fish habitat enhancement that might be considered for mitigation, such as instream structures, may not be appropriate due to the potential channel instability. Managers also need to review existing restoration plans, road maintenance plans, and other work that already has been identified. Mitigation measures for the increased risk of fire in the Resurrection Creek watershed are already spelled out in the All Lands/All Hands program developed with other agencies and the Kenai Peninsula Borough. Fuel reduction goals, public education, and emergency preparedness measures are already lined out and are being implemented. Other entities, such as the Copper River Watershed Project in the Cordova area, have ongoing restoration programs, including the Million Dollar Eyak Lake project. Thus, Forest Service managers may have many opportunities for collaborative work. The greatest issue, however, may be the uncertainty as to how fish and wildlife species may respond to the effects of climate change. Salmon, in particular, are a key part of the ecosystem and the economy in Alaska. Unlike areas in the lower 48 states, coastal streams will have more, not less, water, and water temperatures will not rise enough for lethal effects to salmonids. Direct mortality is unlikely, but increased water temperatures could disrupt seasonal timing and life history cycles of both the fish and the food chains upon which they depend. If, for example, warmer water temperatures cause salmon eggs to mature more quickly, the fry could hatch too early in the season when no prey is available – unless the maturation of zooplankton and other organisms is temperature-dependent and increases as well. Without this basic knowledge, it is difficult to determine how the resources will be affected. There are a number of other biological questions, particularly whether species have the genetic/behavioral plasticity to adapt to changes. As an example, most salmon can have a wide range of spawning times, habitats, and life-history patterns. If eggs develop more quickly with warmer water, perhaps latespawning stocks will preserve the species. Perhaps the best mitigation is for land managers to maintain or restore diverse habitats and the genetic stocks that use them (something managers should be doing anyway). This is not to say populations will not be stressed, and population managers may well need to reduce harvests or take other actions as species adjust. To answer some of the biological questions, researchers from the Pacific Northwest Research Station and a number of universities are conducting studies in the Cordova area. Two current studies involve looking at differences in salmon and aquatic invertebrate life histories and timing, based on different temperature conditions across the Copper River Delta, including some sites in the Eyak Lake watershed. In these cases, physical locations are being used as a surrogate for the temperature changes that are predicted from climate change. Additional baseline data is also being collected on surface and groundwater temperatures, another major data gap. In summary, extensive climate data resources are available through the University of Alaska, Fairbanks, but limited historic data and models may hinder quantitative assessments. However, determining climate change trends, identifying resource values, and analyzing how those resources might be affected may be a sufficient start for determining future actions. In Alaska, where most areas are relatively pristine, it made more sense to focus on more developed watersheds to identify specific issues and actions. Much of the mitigation efforts that need to be done are actions that may already be planned or should be the normal plan of work. Stream projects that restore natural flows and functions may be the best way to protect fish habitat and reduce the risks of floods. Most Forests have conducted watershed assessments, road condition surveys, and fire management plans. The standards may need to be reviewed in light of predicted changes, such as increasing cross drainage or culvert sizes for roads, but most of the problems may already be identified. Lastly, a number of other government entities, agencies, community groups, 268 Assessing the Vulnerability of Watersheds to Climate Change
Chugach National Forest Watershed Vulnerability Assessment, Alaska Region (R10) and NGO’s may have existing programs or grants. This is the case even in the small fishing town of Cordova, Alaska, and the rural Kenai Peninsula. INTRODUCTION The Chugach National Forest is somewhat exceptional in the National Forest system. Most of the Forest is undisturbed, with only 272 miles of road on 5.5 million acres, 175 of which are state or Forest highways. No roads for timber harvest remain open. There are no grazing allotments, no current commercial timber production to speak of, and limited active mineral extraction. From 1985 to 1997, timber harvest averaged 2 million board ft/year, but this was due mostly to the salvage of beetle-killed spruce in the early 1990’s. By 1997, commercial harvest was no longer economically viable. The aquatic resource issues are limited as well. There are no threatened, endangered, or sensitive aquatic species unless one includes the Forest Service Alaska Region-designated sensitive dusky Canada goose (Branta canadensis occidentalis) that nests in the wetlands of the Copper River Delta. With small human population centers in the surrounding areas, limited industry, high precipitation, and no local agriculture, the demand for water is relatively low. There are, however, two diversions for hydroelectric power generation. The main aquatic resource issue is maintaining the high salmon productivity in the streams for the sport, commercial, and subsistence fisheries. Of particular importance are sockeye (Oncorhynchus nerka), coho (O. kisutch), chinook (O. tshawytscha), and pink (O. gorbuscha) salmon. The 2002 Forest Plan and its updates anticipate little development on Forest land except for tourismrelated projects such as the expansion of existing campgrounds, additional trails, and more recreation cabins. Water use and the amount of area affected by these activities would be relatively small. Adjacent landowners have not proposed major development projects. Most of the remaining FS management activities are related to fuel reduction or wildlife and fish habitat restoration and enhancement. Vegetation management for ungulate browse would affect the greatest amount of land with up to 10,000 acres treated with prescribed burns, cutting back mature shrubs, or other treatments. Fuel reduction would affect 4,000 acres over 10 years. Additional areas may be treated with prescribed fire for wildlife enhancement. Most of the necessary stream restoration work has been completed, with the exception of continued restoration of placer-mined areas along Resurrection Creek and Cooper Creek. The trend for fish habitat projects in the future will be elective enhancement projects on a small scale. A recent watershed condition classification study has been completed for the Chugach National Forest. Of the 275 sixth level watersheds, 268 were rated as Condition Class 1 (the best ranking), 7 as Class 2, and none as Class 3. Thus, most of the watersheds are intact and functioning properly. Large landscape disturbances from future development are not foreseen. With some exceptions, when managers examine the effects of climate change, they may find that there is little they can do to improve matters without altering natural conditions. ASSESSMENT OBJECTIVES This study was conducted as part of the USDA Forest Service Watershed Vulnerability Assessment Pilot Project. The purpose of this assessment is to provide land managers on the Chugach National Forest, and similar areas of Alaska, with a method of assessing the vulnerability of watersheds to the effects of predicted climate change. This entails the identification of the important aquatic resources or values, the type and degree of climate change, and the effects on the values. Most important, however, this 269 Assessing the Vulnerability of Watersheds to Climate Change
Page 2 and 3:
AUTHORS AND CONTRIBUTORS Authors* M
Page 4 and 5:
ASSESSSING THE VULNERABILITY OF WAT
Page 6 and 7:
staff; the task group included repr
Page 8 and 9:
Figure 2. Conceptual model for asse
Page 10 and 11:
Figure 3. Density of springs and sm
Page 12 and 13:
Using Historic Data One finding con
Page 14 and 15:
NF (Region 8) relied on information
Page 16 and 17:
level of uncertainty. Though there
Page 18 and 19:
climate (Casola et al. 2005). Only
Page 20 and 21:
sensitivity. Most were derived from
Page 22 and 23:
The sensitivity evaluation typicall
Page 24 and 25:
in exposure. The result of combinin
Page 26 and 27:
highest priority for management act
Page 28 and 29:
to information affected the assessm
Page 30 and 31:
with and rely on in many resource d
Page 32 and 33:
Pilot National Forest Reports Conte
Page 34 and 35:
Assessment of Watershed Vulnerabili
Page 36 and 37:
Gallatin National Forest Watershed
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Helena National Forest Watershed Vu
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Grand Mesa, Uncompahgre and Gunniso
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
Page 116 and 117:
Page 118 and 119:
White River National Forest Watersh
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Coconino National Forest Watershed
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Sawtooth National Forest Watershed
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Shasta Trinity National Forest Wate
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
Page 204 and 205:
Page 206 and 207:
Page 208 and 209:
Page 210 and 211:
Page 212 and 213:
Page 214 and 215:
Page 216 and 217:
Umatilla National Forest Watershed
Page 218 and 219:
Page 220 and 221:
Page 222 and 223: Umatilla National Forest Watershed
Page 230 and 231: Assessment of Watershed Vulnerabili
Page 232 and 233: Ouachita National Forest Watershed
Page 242 and 243: Chequamegon-‐Nicolet National F
Page 274 and 275: Chugach National Forest Watershed V
show all

watervulnerability

Create successful ePaper yourself

Delete template?

Save as template?