1. INTRODUCTION *

2. THE NAZKO RIVER WATERSHED *

3.0 THE NAZKO WATERSHED ASSESSMENT PROCEDURE *

REFERENCES *

APPENDIX A - Complete List of Nazko River Watershed Assessment Multi-agency Roundtable Members

APPENDIX B - Interior Watershed Assessment Procedure Blank Digital Forms

APPENDIX C - Forest Cover Data Statistics

APPENDIX D - Aneko Creek Watershed IWAP Data Sheets and Map with Overlays

APPENDIX E - Brown Creek Watershed IWAP Data Sheets and Map with Overlays

APPENDIX F - Canyon Creek Watershed IWAP Data Sheets and Map with Overlays

APPENDIX G - Clisbako River Watershed IWAP Data Sheets and Map with Overlays

APPENDIX H - Gruidae Creek Watershed IWAP Data Sheets and Map with Overlays

APPENDIX I - Michelle Creek Watershed IWAP Data Sheets and Map with Overlays

APPENDIX J - Redwater Creek Watershed IWAP Data Sheets and Map with Overlays

APPENDIX K - Ross Creek Watershed IWAP Data Sheets and Map with Overlays

APPENDIX L - Snaking River Watershed IWAP Data Sheets and Map with Overlays

APPENDIX M - Summit Creek Watershed IWAP Data Sheets and Map with Overlays

APPENDIX N - Tautri Creek Watershed IWAP Data Sheets and Map with Overlays

APPENDIX O - Udy Creek Watershed IWAP Data Sheets and Map with Overlays

APPENDIX P - Wentworth Creek Watershed IWAP Data Sheets and Map with Overlays

This document was commissioned by the Ministry of Environment, Lands and Parks, Cariboo Region. It contains the results of the application of the Level I Interior Watershed Assessment Procedure (IWAP) to 13 separate watersheds within the greater Nazko River Watershed. The procedure was undertaken as described in the September 1995 version of the Forest Practices Code of British Columbia’s Interior Watershed Assessment Guidebook. Any deviation from the procedure and methodology outlined in this guidebook is fully detailed in section 3.2.

Integral to the IWAP is the formation of a multi-agency roundtable whose purpose is to inform, direct and focus the scope of the analysis. Members to the roundtable should include representatives of resource agencies or land tenure holders with legal obligations in the area undergoing analysis. Members to the Nazko roundtable included representatives from Ministry of Forests; Ministry of Environment, Lands and Parks; timber licensees; and Department of Fisheries and Oceans. A complete list of roundtable members is given in Appendix A.

As described in the guidebook, the IWAP is designed to be applied to complete watersheds of an area between 5 and 500 km² (500 to 50 000 ha). At 4150 km², the Nazko River study area, as defined by the Ministry of Environment, is more than four times the upper limit of 500 km². Carmanah Resources Ltd. was then directed by the multi-agency roundtable to choose representative watersheds in consultation with Pat Teti, the Regional Hydrologist for the Ministry of Forests in the Cariboo Region, and other roundtable members. Using fisheries values, timber harvesting history, and development plans as the decision criteria, the 13 watersheds were chosen for analysis.

The terms of reference for this assessment differs significantly from those presumed by the Forest Practices Code guidebook. That is, the IWAP was not initiated by the Ministry of Forests as part of the forest planning process. Instead, the Nazko River Watershed Assessment was funded as part of Forest Renewal British Columbia’s Watershed Restoration Program. The purpose of this analysis is to provide information for watershed restoration activities. This information may be used by landuse managers to make more informed decisions regarding further forestry development, fisheries and other land-based issues.

The balance of this report contains information directly relevant to the Nazko River Watershed Assessment. It is not intended to be, nor is it, a comprehensive hydrological analysis of the watershed. For additional information regarding the specific requirements and products of the IWAP, refer to the Forest Practices Code of British Columbia guidebook to the Interior Watershed Assessment Procedure (September 1995).

The Nazko River watershed (Figure 1) is located in the Interior Plateau of central British Columbia. The region is typified by low relief and a gentle, rolling landscape interspersed with generally round hills of 200 to 400 meters in relative elevation. The relief never varies more than 400 meters over the entire study area,. The drainage basin area is 4150 km² (415 000 ha), and the Nazko River mainstem is 157 km in length.. The centre of the watershed is located at approximately 52º 45’N latitude and 123º 30’W longitude. In order, from north to south, the watersheds chosen for the application of the IWAP Level 1 are Redwater Creek, Udy Creek, Michelle Creek, Snaking River, Clisbako River, Canyon Creek, Wentworth Creek, Tautri Creek, Brown Creek, Aneko Creek, Ross Creek, Gruidae Creek, and Summit Lake.. Settlements within the watershed include the town of Nazko near the confluence of the Nazko River and Redwater Creek, and the Nazko Indian Reserve at the confluence of the mainstem and Michelle Creek.

The Nazko River watershed lies within the physiographic regions of the Chilcotin and Nechako Pleauteaux. The topography is made up of gently rolling, undissected uplands interspersed with numerous small lakes and wetland areas. The bedrock geology is of volcanic origin, consisting of gently dipping, Miocene/Pliocene olivine basalt flows. The area was heavily glaciated during the Pleistocene. This is reflected by the often thick surficial deposits of mainly unconsolidated glacial deposits. Fluvial and glaciofluvial deposits dominate the mainstems of the Nazko and Clisbako rivers, while the remainder of the basin is overlain by basal and ablationa; moraine deposits of till (Lord and Walmsley, 1988).

The biogeoclimatic zones of the study area fall within the Subboreal Spruce and Engelmann Spruce-subalpine Fir zones. The Chilcotin pine subzone (SBSa) is predominant in the watershed, and is characterized by white spruce and lodgepole pine, and black spruce in wetland areas. The Douglas fir-white spruce subzone (SBSb) follows mainly along the corridor of the lower mainstem, and is dominated by douglas fir, white spruce, lodgepole pine, trembling aspen and paper birch. The wet subzone of the Engelmann spruce-subalpine fir zone (ESSFh) is characterized by subalpine fir and engelmann spruce, and occurs in localized regions of the eastern portion of the drainage basin (Annas and Coupé, 1979).

The climate of the study area is characteristically dry. Average annual temperature is approximately 2° C, with average summer highs in July-August of 14° C and January winter lows averaging -13° C. Average annual precipitation is approximately 440 mm, with an estimated 40 percent falling as snow. The majority of rainfall occurs in June, July and August. Table 1 shows a summary of climatic data for the hamlet of Nazko, B.C.

The Water Survey of Canada gauging station, Nazko River above Michelle Creek (No. 08KF001), has a flow record going back to 1965. Mean annual flow over the period of record is 4.61 m³s^-1. To estimate the mean annual flow for the Nazko River at the mouth, a conversion of the measured discharge by a ratio of the total watershed area (415 000 ha) over the gauged watershed area (324 000 ha) gives a discharge of 5.9 m³s^-1. Average maximum and minimum monthly discharges take place in May and January-February respectively. Summer and winter 7 day low flows calculated by Rood and Hamilton (1995) using records from 1981 to 1990 are 1.27 m³s^-1 and 0.96 m³s^-1 respectively. Low summer flows can affect fish habitat by increasing water temperatures, stranding juveniles and reducing rearing habitat, while low winter flows can dewater redds which harm incubating eggs by increasing the possibility of freezing (Rood and Hamilton, 1995).

Of the 415 000 ha of the Nazko River watershed, 90% of the area is forested. Harvesting in the study area began in the mid-1960’s, the majority taking place over the past 15 years. Slocan Forest Product Ltd. is the largest licensee operating in the study area. From 1982 to 1997, areas logged and areas proposed for logging are estimated at 6.3 percent of the watershed; less than 2 percent of the area was logged before 1982. Within the Nazko watershed, both the Snaking (Rood and Hamilton 1995) and lower Clisbako rivers have been identified as areas of concern with regard to logging.

The major land use activities within the watershed are agriculture and forestry. Some mineral exploration also takes place in the upper Clisbako River sub-basin. Farming is predominant on the mainstem downstream of the Nazko reserve. Surface and groundwater extraction for irrigation, stock watering and domestic use impact the hydrological regime of the watershed mainly in the summer. Furthermore, stream sedimentation via bank erosion caused by cattle may have an effect on the stream. Table 2 summarizes licensed water demand for the Nazko River.

The purpose of the Level 1 Interior Watershed Assessment Procedure is twofold. Firstly it is designed to assess the sensitivity of a watershed to hydrological changes as a result of landuse change or disturbance. Secondly, it assists in quantifying the extent and impacts of current and historical landuse practices, and forestry in particular. Additionally, the Assessment is intended to meet the requirements of future assessments mandated by the Forest Practices Code

The procedure was carried out according to its hierarchical structure which assesses thirteen impact measurements and related anecdotal information. The data was collected from various sources. The two primary sources of relevant data were the Ministry of Forests and the Ministry of Environment. The Ministry of Environment provided the Terrain Resource Inventory Maps (TRIM) which formed the spatial and positional base for the analysis. These digital maps contained all of the landform, contour, hydrological and road information required for the analysis. They are the standard for spatial analysis in British Columbia, and are the most accurate mapping products presently available. The Ministry of Forests provided the digital Forest Cover maps which contained detailed information relating to all aspects of forestry activity. A blank data entry form is located in Appendix B. There are 4 chief areas of analysis: Peak Flow, Surface Erosion, Riparian Buffer, and Landslide measurement.

The purpose of the Peak Flow measurements are to evaluate the potential for changes in both the timing and magnitude of maximum discharge. In a snowmelt dominated hydrological regime, such as that of the Nazko study area, the peak flow occurs during the spring freshet as the winter snowpack melts. The H₆₀ line, or line above which 60% of the watershed area lies, is an attempt at defining the location of the snowpack prior to the initiation of the spring freshet. Once this has been calculated, it is then possible to determine the areal extent of logging and categorize it as being either above or below the H₆₀ line. Forest harvesting can change the shape of the natural hydrograph. When trees are removed water is no longer taken up by the vegetation thus increasing the soil moisture content. The primary effect of this removal is increased peak flows, as water is no longer required by the vegetation or to recharge soil moisture. The increased soil moisture content reduces the ability of the soil to absorb water. As a result, large storm events or rapid snowmelt more often results in the overland flow of water streamward. This process is additionally facilitated by the existence of roads which provide an additional sediment source. This process then delivers sediment to the stream. The water yield from logged areas is also increased as trees are no longer available to either intercept rain or snow, or shade the snow from direct solar radiation and wind during spring. So then, there is both more snow available for melting (ablation) and it melts faster. Taken together, the above affect the channel system by increasing sediment load and peak discharge.

Roads and especially road crossings are significant potential sources of sediment supply to the hydrological system. Roads expose soil to increased erosion by rain and snow, and can often provide pathways to streams, creeks and rivers. Road crossings are of particular concern because they are immediately adjacent to streams, shortening the distance from the sediment source. The Surface Erosion impact indicators are consequently measures of these variables.

The third impact category is Riparian Buffer. The riparian buffer refers to the vegetative region that borders a waterway or body. Riparian areas often contain smaller side channels, overhanging trees and shrubs, and deliver large woody debris to the channel. In short, they provide many of the characteristics necessary for productive fish habitat. Increased sedimentation or logging of the riparian buffer can destroy fish rearing and spawning sites, thus destroying a fishery value of the stream.

The increased soil moisture content sometimes associated with logging can provide additional impetus for increased occurrences of mass movement events. The addition of relatively modest amounts of water to an already saturated slope may result in slope failure and landslides. The last impact category, Landslides, provides a measure of the number of landslides as well as an inventory of steep and therefore potentially unstable slopes (>60%).

The Forest Practices Code Interior Watershed Assessment Procedure Guidebook defines the methodology and procedures of the Interior Watershed Assessment. However, since its publication in 1995, data availability and the application parameters have changed. Most importantly for this assessment are the modification of the terms of reference (see section 1.0) and the delivery agency. The data from this analysis is not in any way part of the Ministry of Forests’ formal planning process. It is, rather, intended for inventory and watershed restoration purposes only. In addition, the delivery agency is not the Ministry of Forests as presumed by the guidebook. Instead, the report was commissioned by the Ministry of Environment, whose digital data delivery requirements differ significantly from those of the MoF. These two factors affected the prescribed procedure in the following manners.

The Ministry of Environment’s Terrain Resource Inventory Maps (TRIM) are now available for almost the entire province. With respect to positional accuracy and landform descriptions, these maps are the highest quality available today. Consequently, rather than changing the TRIM base from the more accurate North American Datum (NAD) 1983 to NAD 27 as suggested in the guidebook, the procedure was reversed. This method has the advantages of maintaining the positional accuracy inherent in the TRIM base, while at the same time producing a series of coverages in the MELP standard form.

A related modification was the preferential use of TRIM data whenever possible. The guidebook suggests that TRIM be used to provide a base with which to augment the Forest Cover data (FC1). In the interest of positional accuracy and appropriate formatting, the Forest Cover information was selectively chosen from the FC1 data to provide information pertinent to the analysis. The positional accuracy of the TRIM base was maintained and any further data compatibility problems were minimized.

This section presents the results of the application of the Interior Watershed Assessment Procedure to the Nazko River watershed. The tabular manner in which the results are presented is intended to allow the reader to easily compare the results of individual watersheds. Most useful are the density measurements, which allow for fair comparison of individual watersheds.

An extremely useful product of the IWAP is the mapping products which are produced as an integral part of the final product. These maps facilitate intuitive comparison of watersheds and visual analysis of the many phenomena which cumulatively result in the hazard impact scores. Small scale maps of the study area watersheds showing roads, rivers, wetlands, lakes, slopes greater than 60 percent, H₆₀ lines and the tree stand heights used in the equivalent to clear-cut area (ECA) calculations are contained in Appendices D through P. With each watershed map is the completed IWAP calculation sheets. These sheets summarize the measurements, indicators, scores and hazard indices in each of the four hazard analysis areas (i.e. Peak Flow, Surface Erosion, Riparian Buffer and Landslides).

The watersheds under consideration vary greatly in relative areal extent. Table 4 gives the area breakdown for each watershed. Of note is the relative consistency of the elevations of the H₆₀ lines, which range over 200 metres only. The purpose of the H₆₀ line is to indicate the likely location of the snowline at spring freshet. It is designed to be applied over all Interior watersheds. Like all generalizations, it compromises specificity for general applicability. Consequently, there are exceptions. The Nazko study area watersheds are exceptions. They are low relief watersheds and the snow melts both earlier and more rapidly. The hydrograph peaks in early May and descends rapidly through June and July achieving baseflow in mid to late August (Rood and Hamilton 1995).

Table 4. Areal measurements of the study area watersheds by elevation.

The Peak Flow index score results from the weighted combination of equivalent clear cut area (ECA). The ECA is calculated to estimate the hydrological recovery of a watershed following harvesting. As such, burn areas , slides and hydro-cuts are considered clear-cuts with 0 percent recovery. Private land of less than 15 percent of the total watershed area is excluded from these calculations. In the ECA calculations, tree height is used as a surrogate to estimate the extent of hydrologic recovery. The lower the tree height, the more hydrological equivalent the area is to a clear cut. The relative importance of the ECA is weighted according to whether it is above or below the H₆₀ line. The ECA above the line is given 50 percent more weight in the summary calculation of the Peak Flow index score. Below, table 5 presents the ECAs for each watershed.

Table 5. Peak Flow index measurements and results

Road lengths for the watersheds were measured digitally directly from the relevant TRIM maps. In general, these maps do not show the full extent of roads within the watershed. It is often then preferred that the forest cover maps be used for calculations involving roads. However, the positional accuracy of these maps is significantly less than that of the TRIM maps. As this directly affects the hazard calculations, the TRIM data was preferentially used.

Table 6. Road inventory and density

Digital terrain maps are not available for the Nazko study area. It was consequently not possible to use these maps in the delineation of sensitive or erodible soils. For the purpose of the calculations, erodible soils were considered to be all slopes of greater than 60 percent. This is in adherence to the guidebook (pg. 59), but given the relatively flat nature of the watersheds it is not a satisfactory surrogate measurement. There are thick surficial deposits of glacial materials over the study area. Some of these materials are potentially erodible. The spatial union of erodible soils, roads and streams is shown in table 7. With respect to their genesis, the erodible soils density measurements are likely underestimates.

Table 7. Roads adjacent to streams

Table 8 compares the length of streams logged to total stream length. These numbers are used to calculate the Riparian Buffer hazard index.

Table 8. Riparian Buffer impacts

The full extent of fish bearing stream through the watersheds is not accurately known. For the purposes of this analysis, then, all non-intermitent streams were assumed to be fish bearing.

In the IWAP, unstable terrain is defined as slopes greater than 60 percent. Which, in the case of this analysis, is the same criterion used to determine the extent of erodible soils. Although the measurements are in some cases the same, they are attributed different impact hazard scores because they are reported in a different context. In other words, 1 km of road on a slope greater than 60 percent is given a different hazard potential than 1 km of road on erodible soil. Table 9 shows the length of roads on unstable terrain in the context of mass movement potential. It also gives the density of streams whose banks have been logged on slopes greater than 60 percent in km per square km. Again, the relatively flat nature of the study area is reflected in these measurements.

Table 9. Mass Wasting hazard measurements

Table 9 (CONTINUED). Mass Wasting hazard measurements

Although forestry is the principle landuse activity in the study area, the area is also used for unrelated activities. Among these is agriculture. The area, particular in the northern part of the study area and around the village of Nazko, is used for both crops and cattle. The area is also used for game hunting, and many of the roads are open to recreational use. Some other relevant landuses are found detailed below.

Table 10. Other landuses

Table 10 (CONTINUED) Other landuses

The Nazko study area is almost entirely crown land, most of which is used for timber supply. Table 11 summarizes these ownership properties.

Table 11. Watershed ownership characteristics

Table 12 provides physical descriptions of the watersheds, including hydrological zone, bedrock geology and area with unstable slopes. As described earlier, unstable areas are defined as those areas with slopes greater than 60 percent. In the Nazko study area, there is a small percentage of area which meets this criteria due to the relatively flat to rolling nature of the landscape. Appendices D through P contain individual overlays which illustrate the extent of these areas within each watershed. Dominant bedrock geology is numerically coded to a table contained in the IWAP guidebook. Class "9" is described as "volcanic (basalt) - flows/breccias/porphyries/greenstone" (page 79). As such, it best describes the bedrock geology of the Nazko study area. However, the area was glaciated repeatedly during the Pleistocene (at least three times). In some areas, then, there exist deep deposits of surficial materials of glacial origin.

Table 12. Physical characteristics by watershed

The watershed report card, table 13, summarizes the hazard index scores in each of the impact categories for each watershed. The index scores were calculated from the data derived from the digital database which was described in detail in sections 3.2.1, 3.2.2 and 3.2.3. The calculations were completed using a combination of the IWAP Excel data entry and calculations spreadsheets, and long-hand checks. The measurements and calculations undertaken as part of this assessment followed closely the procedure described in the guidebook. The hazard impact index numbers displayed below provide only coarse indications regarding watershed hydrological impacts. As a coarse filter, the numbers simply point to potential concerns. It is the interpretation of the impact number which contextualizes the concerns.

Table 13. Watershed Report Card.

Alone, the hazard impact scores provide a gross indication of potential hydrological impacts. The purpose of this section is to interpret the numbers within the context of the data quality and limitations described.

The following section will review and the interpret the specific assessment results on a watershed by watershed basis. The individual watershed data entry and calculations sheets, together with the watershed maps, should be used to augment the understanding of the results and aid interpretation. The sheets and maps are to be found in Appendices D through P. All of the information referenced in the following watershed sections comes directly from either the sheets or the maps

The hazard indices for Aneko Creek indicate no cause for concern. The scores are all low, and there are no obvious data quality problems.

Table 14. Aneko Creek watershed report card

The Peak Flow hazard index for Brown Creek is moderately high. All other scores indicate no cause for concern. The Peak Flow index is the result, in this case, of high ECA, particularly above the H₆₀ line. Because of the rather gentle topography in the watershed, the hazard index may be overestimating the potential dangers of peak flow. However, there are a large number of streams in the watershed, many of which intersect with forest activity, which are marked as intermittent on the TRIM sheets and were consequently removed from the analysis. Many of these features appear non-intermittent on aerial photographs and on NTS maps. Consequently, the Surface Erosion and Riparian Buffer indices may be underestimating the extent of damage, and the potential for impacts in the watershed.

Table 15. Brown Creek watershed report card

The hazard indices for Canyon Creek indicate no areas of concern. The scores are all low, and there are no obvious data quality problems.

Table 16. Canyon Creek watershed report card

The hazard scores for the Clisbako watershed all indicate no significant impacts or potential impacts. One possible concern, however, is the concentration of logging activity along the mainstem of the Clisbako River. Because the watershed is quite large, the unlogged portions of the watershed act as a statistical buffer, and the density measurements are consequently decreased. Although the overall portion of the watershed which has been logged is quite small, the portion of the mainstem itself which has been logged is cause for potential concern.

Table 17. Clisbako Creek watershed report card

The hazard indices in the Gruidae Creek watershed are all low, and no areas of concern are indicated.

Table 18. Gruidae Creek watershed report card

The Peak Flow index for Michelle Creek is moderately high, indicating potential concern. This score is driven largely by the road density above the H₆₀ line, suggesting that it may be overestimating the degree of impact. However, the total road density (1.14 km of road per square km) is sufficiently high as to be of concern itself. A second, lesser, concern, which also contributes to the high Peak Flow score, is the high ECA.

Table 19. Michelle Creek watershed report card

The hazard indices all indicate no cause for concern.

Table 20. Redwater Creek watershed report card

The hazard indices show no areas of concern.

Table 21. Ross Creek watershed report card

The hazard scores indicate no obvious impacts in the Snaking River watershed. One possible area of concern, though, is the high density of logging activity along the mainstem of the Snaking River. Although the actual density of logging in the watershed is quite low, there may be impacts on the mainstem itself.

Table 22. Snaking River watershed report card

There are no obvious areas of concern in the Summit Creek watershed. The hazard scores are all low, and there are no apparent data quality problems.

Table 23. Summit Creek watershed report card

There are no areas of concern indicated by the hazard indices. One potential concern not indicated, though, is the density of stream crossings and density of roads within 100 m of streams. If intermittent streams are included in the analysis — and for the reasons stated in section 3.4.2 there is reason to believe in some cases they ought to be — the number and density of these indicators would increase dramatically. This would consequently increase the Surface Erosion score.

Table 24. Tautri Creek watershed report card

Although the hazard scores do not indicate any immediate cause for concern in the Udy Creek watershed, two other factors could indicate impacts on the hydrological system. First, the number of intermittent streams indicated in the watershed may be erroneous, and their inclusion in the assessment could significantly affect the results. Second, there is evidence of range use next to the creek which is not accounted for in the Forest Cover data. The possible consequences of range use are increased damage to the riparian buffer, increased sedimentation of the stream, and possible small scale slope failures along the banks.

Table 25. Udy Creek watershed report card

There are no evident causes for concern in the Wentworth Creek watershed.

Table 26. Wentworth Creek watershed report card

The Interior Watershed Assessment Procedure is a general assessment tool designed for application throughout the interior of British Columbia. As a general diagnostic filter, it measures many important hydrological and landuse parametres. The hazard index calculations used to determine the scores are formulated to be used in an average interior watershed. When considered from this point of view, the Nazko watershed is arguably not an average interior watershed. Its geological and geomorphological history conspire to make the IWAP too general to result in a completely accurate assessment. And this should be taken into consideration when interpreting the results and considering future assessments. The flat to rolling topography of the study area renders the H₆₀ line largely insignificant: the low relief means that rather than having a snowpack which lasts further into the spring, it undergoes snowmelt earlier and more rapidly. That is, there is not a significant higher elevation snowpack which remains later into the spring to be affected by clearcutting. Instead, it melts earlier due to the relatively low elevations. Thus the differential ECA weighing for areas above and below the H₆₀ line does not accurately estimate the actual situation.

Another anomaly of the study area is the glacial history. The area was glaciated numerous times. Most recently, it was glaciated during the late Wisconsinan Fraser glaciation. Pre-existing thick deposits of surficial materials and relatively soft volcanic bedrock combined to create a heavily incised landscape which has a drainage density which exceeds that necessary to balance hydrological inputs. This is illustrated by the large number of wetlands within the study area. In the context of the IWAP procedure, the effect is to remove many riparian habitats from the assessment. Consequently, in some cases the damage to the riparian buffer may be underestimated. Table 27 summarizes the findings of the assessment.

Table 27. Summary of Results

Two of the watersheds assessed in this analysis proved to contain potential significant hydrological concerns. As such they are eligible for additional Level 2 (Channel Assessment Procedure). Furthermore, concerns over data quality prompt the recommendation of aerial photograph based CAPs for three additional watersheds. The application of a Sediment Source Survey to two of these watersheds is also recommended.

As a watershed assessment and inventory project, this analysis has shown the forest harvesting and associated activities, such as road building, have potentially affected the hydrological regimes of five of the thirteen watersheds included in this study.

The application of the Channel Assessment Procedure (CAP) to selected watersheds within the study area would further define the location and magnitude of the hydrological impacts. Following this, restoration prescriptions may be appropriate. The decision to apply the CAP should be dependent on both the value of the stream and its prospects for restoration. Table 28 summarizes the recommendations following the application of the Interior Watershed Assessment Procedure to the Nazko River study area.

Table 28. Summary of Recommendations

Annas, R.M. and R. Coupé (eds.) 1979. Biogeoclimatic zone and subzones of the Cariboo Forest Region. Ministry of Forests, Victoria, B.C. 103pp.

Carmanah Research Ltd. 1997. Nazko River Stream and Fish Habitat Assessment. Prepared for the Ministry of Environment, Lands and Parks, Cariboo Region, Williams Lake, B.C.

Lord, T.M. and Walmsley. 1988. Soils of the Nazko Area, British Columbia. Land Resource Institute, Vancouver, B.C. 62pp, 2 maps.

Struik, L.C. 1988. Structural Geology of the Cariboo Gold Mining District, East-central British Columbia. Geological Survey of Canada, Memior 421. 100 pp, 4 maps.

Forest Practices Code of British Columbia. 1995. Interior Watershed Assessment Procedure Guidebook (IWAP). Province of British Columbia. 82pp.

Geological Survey of Canada. 1959. Map no. 12-1959, sheet 93B, bedrock geology, Quesnel, B.C. Department of Energy, Mines and Resources, Ottawa, Ont. (map only)

Geological Survey of Canada. 1960. Map no. 49-1960, sheet 93G, bedrock geology, Quesnel, B.C. Department of Energy, Mines and Resources, Ottawa, Ont. (map only)

Rood, K.M. and R.E. Hamilton. 1995. Hydrology and water use for salmon streams in the West Road Habitat Management Area. British Columbia. Can. Manuscr. Rep. Fish. Aquat. Sci. 2295: 82pp.

Tipper, H.W. 1971a. Multiple Glaciations in Central British Columbia. Canadian Journal of Earth Sciences, 8: 743-752.

Tipper, H.W. 1971b. Glacial Geomorphology and Pleistocene History of Central British Columbia. Geological Survey of Canada, Bulletin 196.