River Crossings and Migratory Fish: Design Guidance FOREWORD Sarah Boyack MSP John Home Robertson MSP Migratory fish such as salmon and sea trout are an important recreational and commercial resource in Scotland, as well as being integral components of Scottish biodiversity. The associated tourism and angling industries are also important contributors to the Scottish economy, particularly in rural areas. However, salmonid populations in Scottish waters are currently under pressure. The decline has been attributed mainly to a reduction in the numbers of fish surviving to return after the marine part of their life cycle. The causes for this reduced survival are not clear but changes in the marine environment are undoubtedly involved. There is little we can do directly to reverse any changes there have been in the ocean, so we are left to exercise control where we can, particularly by ensuring that the freshwater environment is as productive as it can be. River-crossing structures such as culverts can, if not properly designed, form a barrier to the movement of migratory fish. That is why two Scottish Executive Departments, in consultation with fishery interests and practitioners involved in the road design process, have developed this guidance. It is our aim to implement the approach detailed in this document on all trunk road new-build and maintenance projects. The approach adopted in 'River Crossings and Migratory Fish' ensures that the free passage of migratory fish is not impeded by new river-crossing structures associated with the trunk road network. This will assist in the sustainable management of fish stocks by maximising the area of habitat available to spawning fish, which will in turn enable the populations to better withstand the many stresses to which they are currently exposed. The approach also prevents habitat fragmentation, which is a principle detailed in the Scottish Executive publication 'Trunk Road Biodiversity Action Plan'. But the guidance contained in this document should not be limited to the trunk road network. We hope that all those involved in designing river-crossing structures will adopt the guidance offered. While practitioners will find 'River Crossings and Migratory Fish' of immediate use, only through application, feedback and development can the document's robustness be established. We have therefore initiated a twelve-month consultation period, during which you are formally invited to apply the document's contents and provide comments and suggestions for its improvement. Arrangements are also being made towards taking 'River Crossings and Migratory Fish' forward for inclusion in the UK Design Manual for Roads and Bridges. We commend 'River Crossings and Migratory Fish' to you and look forward to feedback on its use and application. Sarah Boyack MSP Minister for Transport and the Environment John Home Robertson MSP Deputy Minister for Rural Affairs (Fisheries) EXECUTIVE SUMMARY Introduction Fish passage at stream crossings is an important consideration in the planning, design, installation and upgrading of river-crossing structures. The purpose of this publication is to give design guidance to the engineer and others with an interest in river crossings that will ensure free fish passage can be achieved. For many fish, migration is essential to the survival of the species. Salmon, for example, travel from the sea up river to spawn, and both juveniles and spawned adults migrate downstream to the sea. Other fish such as trout migrate upstream and downstream during their life cycle seeking a variety of aquatic habitats for spawning, rearing young and hiding. Although these migrations may only be over a few kilometres, they can be important for the long-term survival of the species and maintenance of fish production in a watercourse. Improperly planned and designed culverts and other river-crossing structures can be barriers to such migration. Common problems at river crossings are mainly associated with culverts, but can also be present at bridges, fords and weirs, and include: inadequate water depth during periods of migration; excessive water velocities; and vertical barriers to fish passage (e.g. perching). The Road Planning Process Avoiding or minimising obstruction to fish passage requires consultation by the engineer with SEPA, SNH, SERAD and DSFBs throughout the design process to ensure that all relevant requirements are identified (see Figure 1). The resolution of engineering, biological, hydraulic and cost factors requires a balanced and interactive approach across these disciplines so that structures do not present a barrier to fish migration. The first three steps indicated can be equated to the three stage DMRB assessment process used in the development of a road project. The process is also relevant to minor improvement and major maintenance projects although these are not subject to the three stage process. Design Requirements for Fish Passage In general, fish will be able to travel through a river crossing structure provided that the conditions in the structure are not substantially different from those in the existing watercourse. The design parameters detailed in Table 1 have been developed to ensure the free passage of most migratory fish species through river-crossing structures (specific advice relating to individual fish species is given in Table 5.1 of this document). These parameters must be incorporated into the design of new or altered structures to ensure that they do not present a barrier to migrations. It is not necessary to design for fish passage at all flow conditions. A suggested "passage design flow range" for checking for excessive velocity at high flows and inadequate water depth at low flows is the 10 percentile and 90 percentile of normal flows respectively (the flows which are exceeded for 10% and 90% of the time). The preferred form of structure is one in which the characteristics and dimensions of the original watercourse are maintained. This may be achieved by using a bridge or a culvert. If using a culvert, the following alternatives should be considered in turn until a successful solution for fish passage is determined: Case 1 : Culvert barrel with dimensions derived for flood flow conditions; Case 2 : Culvert with depressed invert to allow for inclusion of stream bed material within the barrel; Case 3 : Provision of a bottomless arch culvert to retain the natural stream bed; Case 4 : Provision of a low flow channel within the culvert invert; and Case 5 : Provision of baffles within the culvert. Table 1 Design Criteria for Salmonids Design Factor Maximum water velocity at 10 percentile flow (mean over crosssection) (1) Target Criteria Up to 20m culvert length 20 - 30m culvert length over 30m culvert length 1.25m/s 1.0m/s 0.8m/s Minimum pipe diameter 0.5m Minimum water depth at 90 percentile flow (1) 0.3m Maximum water level drop (1) 0.2m Minimum gap on trash screen (if applicable) 0.2m (1) also relevant in bridge design Existing Problem Sites There are two approaches to retro-fitting existing culverts and bridge aprons to allow for fish passage: (a) raising the tailwater level by installing a weir which backs up water; and (b) installing baffles. Design details of these measures are contained in Chapter 7 of this document. Both are effective in deepening water levels and reducing excessive velocities. However, they result in a reduction of the structure's flow capacity which may have significant effects on upstream flooding during storm flow conditions. PART 1 1 INTRODUCTION 1.1 Historically there has been little consideration given to fish passage in the design of in-river road structures. As a result fish which migrate in Scottish rivers and streams may be obstructed and unable to use habitat upstream or downstream of a culvert or bridge crossing. 1.2 A variety of interrelated factors affect the design of any in-river road structure including hydrology, topography, engineering and costs. Environmental issues including the requirements of fish must also be taken into account. 1.3 The purpose of this guidance is to identify good practice which will ensure that the free passage of fish in watercourses is not compromised by the construction, operation or maintenance of any public road. The potential to improve existing structures is covered as well as the design of new structures. 1.4 The guidance adopts an integrated approach to engineering, hydraulic and fish passage design. Wider environmental issues, such as aesthetic considerations and requirements of other fauna, are not covered. Appropriate guidance on these issues should be used in parallel with this guide. 1.5 The guidance concentrates on the requirements of species such as salmon and trout but also considers the implications of in-river structures for other migratory and non-migratory species. 1.6 The design of a variety of road structures including culverts, bridge aprons, fords and weirs is considered in this document. River diversion works are not included. 1.7 The guidance is intended for all those with interests in the design of in-river road structures including engineers, hydrologists and environmental consultants as well as local authorities and agencies such as SEPA and SNH, and other organisations including District Salmon Fishery Boards (DSFBs). 1.8 It is intended that this document should be used in conjunction with other relevant guidance including the recent CIRIA Culvert Design Guide (1997). The stepby-step approach which is adopted can be loosely related to the three stage process advocated in the Design Manual for Roads and Bridges (DMRB), Volume 5 and it is intended that the guidance should be used in the assessment and design processes. The guidance should also be used when existing in-river road structures are upgraded, for example during major maintenance or to accept heavier loads. 1.9 The guidance provides background information, as well as guidance on the assessment of requirements and design. The remainder of the document is set out as follows: Chapter 2 discusses Life Cycles and Migrations of relevant fish species; Chapter 3 reviews Common Problems for Fish Passage at River Crossings; Part 2 - Assessment Chapter 4 introduces the Assessment Process which should be followed in the evolution of the road proposals to ensure that the requirements for fish passage are adequately addressed. Part 3 - Design Chapter 5 introduces Design Requirements for Fish Passage. Chapter 6 provides Design Considerations. Chapter 7 describes options for Improvement at Existing Problem Sites. 1.10 The document is supported by the following: A Glossary of technical terms. Appendix A which provides details of District Salmon Fishery Boards. A Technical Report which is available from the Scottish Executive. 2 FISH LIFE CYCLES AND MIGRATIONS 2.1 Several species of fish living in Scottish rivers migrate between the sea and the upper reaches of rivers during their life cycle. Others make significant migrations within fresh water. River-crossing structures have potential to disrupt the life cycles of such species by interfering with both upstream and downstream movement. The overall production of fish stocks is limited by the area available for spawning and rearing. Optimum yield will depend upon access to as much of the catchment as possible. Often the best spawning and rearing areas are in small upland tributaries. In the case of salmon and sea trout, the fish return to spawn in the tributary and even the same part of the tributary where they themselves were spawned and reared. This has led to the formation of genetically distinct sub-stocks in larger catchments, which are likely to be adapted to conditions in that part of the catchment. It is therefore important that all spawning areas are accessible on a regular basis for the maintenance of the genetic integrity of the sub-stocks. Atlantic Salmon 2.2 The Atlantic salmon (Salmo salar) is widespread throughout Scotland. The adult fish (typically 55 to 100 cm or more in length) may spawn in quite small headwater streams as well as in suitable areas in larger watercourses. The adult fish enter rivers from the sea at almost any time of year, but they migrate into smaller spawning streams on elevated flows following rainfall in the autumn (September November). After spawning in October to December the adult fish return seawards over a period of up to several months. 2.3 The eggs are laid in areas of gravel where there is an adequate flow of water. After hatching, the young fish remain within the gravel for several weeks, eventually emerging in March to May. The fry disperse for distances of up to several hundred metres downstream. As the fish grow (known as parr at this stage) they redistribute themselves, generally downstream in direction. After 2 to 4 years the parr develop a silver colour and migrate seawards, usually in April to June. At this stage they are termed smolts. The survivors return to spawn after 1 to 3 years of feeding and growing in the sea. Trout 2.4 There are two forms of trout (Salmo trutta) in Scottish waters: the sea trout, which migrates to the sea and the brown trout, which migrates only within the river catchment. Sea Trout 2.5 The migratory sea trout has a life history very similar to that of the salmon. The main differences are that the fish may return to fresh water after only a few months at sea, and the adults are generally smaller than salmon (typically 25 to 60 cm). The adults may also enter smaller spawning tributaries earlier than salmon, often penetrating to the upper headwaters during the summer. A higher proportion survive to spawn again than is the case for salmon. Brown Trout 2.6 Brown trout spend their whole life cycle in fresh water, but may nonetheless make extensive migrations between upper headwaters and the main river and lochs. The timing of these movements is similar to that of salmon, but the adult fish may be very much smaller, typically 15 to 50 cm in length. Lamprey 2.7 Sea lamprey (Petromyzon marinus) and river lamprey (Lampetra fluviatilis) have similar life cycles. Eggs are laid in the gravel in streams and the young fish spend several years living in silt banks in fresh water before migrating to sea to feed and grow, returning to the river to spawn. Lamprey do not enter such small and rocky headwaters as salmonids, but nevertheless where they occur they can be affected by structures which do not permit access to their breeding grounds. Their swimming ability is limited, but they are able to ascend fairly rapid rocky reaches using their oral sucker to hold on between bursts of activity. Eel 2.8 Eels (Anguilla anguilla) are also migratory but have quite a different life history, breeding in the sea and ascending the river as juveniles to feed and grow. They may migrate to the highest headwaters, but may take up to two years to do so. Eels may spend up to 40 years or more in fresh water before returning to sea to spawn. They are small when migrating upstream (typically 6 to 30 cm) with only limited swimming ability but are adept at exploiting slower moving water among rocks and in-stream vegetation. Grayling 2.9 The European grayling (Thymallus thymallus) is a river dwelling fish which has been introduced to several river systems in south and east Scotland. They make limited migrations within the river systems and spawn in spring close to where they live the remainder of the year. Summary 2.10 Some details of upstream and downstream migrant fish in small streams are summarised in Tables 2.1 and 2.2. Table 2.1 Details of Upstream Migrant Fish in Small Streams 1 Species Typical Size Range Main Migratory Period Water Temperature Range Flow Conditions Salmon 55-100 cm SeptemberNovember 2º-15ºC elevated flows Sea trout 25-60 cm JuneNovember 2º-20ºC all but the lowest flows Brown trout 15-50 cm SeptemberNovember 2º-15ºC elevated flows Eel (elvers) 6-10 cm AprilSeptember 8ºC+ all flows Eel (older fish) 10-30 cm July-September 10ºC+ all flows Sea lamprey 40-100 cm May-June 15ºC all flows River lamprey 25-40 cm SeptemberMarch 5-15ºC all flows Grayling 20-40 cm March - May 4-10ºC all flows 1 Temperature and flow conditions are relevant to the upstream migration because of their impact upon swimming performance and current speeds within culverts. These factors are not relevant to downstream migration. Table 2.2 Details of Downstream Migrant Fish in Small Streams Species Stage Range Typical Size Migratory Period Main Salmon and trout Spawned adults 15-100 cm November - May Salmon and trout Fry 4-6 cm April - July Salmon and trout Parr 7-12 cm September - March Salmon and trout Smolts 12-22 cm April - June Eel Adults 25-60 cm June - November Burst / Cruise Speed 2.11 The capacity of fish of various species and sizes to swim against fast currents and to leap at obstacles is clearly fundamental to consideration of the design criteria for in-river structures. Fish have two basic swimming modes: burst speed swimming and cruising speed swimming. Burst speed can be maintained for only a matter of seconds, and quickly leads to fatigue. The maximum velocity and the time for which it can be maintained are strongly influenced by water temperature. Fish can swim faster at higher temperatures but are unable to maintain swimming activity for as long as they can at lower temperatures. Cruising speed can be maintained for extended periods or even indefinitely. In Chapter 5 these observations are used to provide water velocity criteria for various sizes of fish for culverts of different lengths based upon the swimming ability of the fish. These involve minimising the requirement for fish to use burst speeds to attain passage. 2.12 Although salmonid fish in particular are renowned for their leaping behaviour, successful leaps to overcome obstacles are dependent upon certain conditions of water flow at the take-off point and depth and velocity at the landing point. At culvert outlets and inlets in particular these conditions may not occur. Further, salmon and trout only leap at obstructions when they have to, their preferred method of ascent being fast swimming wherever possible. The other species of interest do not leap at obstructions at all. Good design criteria for culverts should minimise the requirement for fish to leap and to use burst speeds. 3 COMMON PROBLEMS FOR FISH PASSAGE AT RIVER CROSSINGS Introduction 3.1 Some river crossings may pose a problem for fish passage because some or all of the fish that attempt to pass the structure cannot do so, or can do so only with difficulty, under the environmental conditions prevailing at the time. This may be due to some hydraulic feature of the structure, such as high water velocity, inadequate water depth or extreme turbulence or due to very large level changes in the watercourse (falls) or as a result of the physical nature of the structure obstructing passage, such as small pipes or narrow grids. While some river-crossing structures are effectively impassable to upstream migrants at all times, many others are passable only by certain species or sizes of fish under only part of the annual range of environmental conditions. Delay caused by this can be an important factor not only in terms of reaching spawning grounds in time but in making fish more vulnerable to predation and poaching. 3.2 Success of passage through such structures will be affected by many factors including: the species of fish: some fish are stronger swimmers or more adept "leapers" than others; the size of the fish: generally large fish can swim faster than smaller fish but larger fish require a greater depth of water to swim in; the condition of the fish: fish heavy with spawn are likely to be less agile than immature fish, and fish may be tired by their migration up to the crossing (particularly if migrating salmon and sea trout are a long way from the sea and have not fed since then); the stream discharge: the hydraulic conditions within and around the structure (e.g. velocity, depth and turbulence) may vary substantially with changes in discharge -which may vary 1000 fold or more between dry-weather flow and peak flow at some sites; and water temperature: generally speaking fish can swim faster at higher water temperatures. 3.3 Bridges generally result in fewer problems for fish passage than culverts because the original channel dimensions, gradient and stream bed tend to be retained. Bridge aprons or associated weirs can, however, cause problems. 3.4 Common problems at river crossings which have been encountered are described in the remainder of this chapter. Inadequate Water Depth 3.5 Inadequate water depth for fish swimming can occur at low flows and/or in wide shallow culverts. This is also linked with the gradient and water velocity in a culvert where faster currents will result in shallower depths in a given culvert cross-section. 3.6 Bridge aprons which are flat in cross section may result in inadequate water depth for fish to swim effectively and safely. Similarly, fords may result in flows spread too thinly for fish passage. Perched Structures 3.7 Perching is a term applied to a culvert outlet (the downstream end) which is set above the stream bed immediately downstream, so that there is a fall. This can occur when the culvert is installed too high, resulting in erosion of the downstream channel. While salmon and trout are capable of leaping at falls to surmount them, conditions at culvert outlets are frequently not conducive to successful jumps. The stream below the fall may be shallow and the water turbulent, representing poor conditions for "take off" for a leap. Water shooting from the culvert, rather than falling vertically, may confuse fish which may jump at the wrong point. Shallow, fast flowing water inside the culvert barrel presents difficult conditions for fish landing after a leap and the fish may be washed downstream out of the culvert. 3.8 Bridge aprons and weirs can also become perched in a similar way to culverts and can then cause difficulties for fish passage. Culvert Inlets 3.9 Changes in the stream hydraulics at the culvert inlet resulting from the constriction of the flow into the culvert barrel may cause problems to fish passing upstream even though they have successfully negotiated the culvert itself. Steep Culvert Gradient and Smooth Barrels 3.10 Excessive water velocity that impedes fish passage may occur when the gradient of a culvert is too great. The problem becomes more severe in periods of high flow and in installations with smooth walls, particularly if there are no resting places (e.g. behind baffles) for fish within the barrel. Inadequate Culvert Diameter 3.11 Inadequate culvert diameter for fish to swim through can occur where a number of small pipes are provided rather than one large barrel. Even a pipe which is physically large enough for fish passage may deter the passage of fish if the fish is reluctant to enter a confined space. Lack of Rest Places and Pools 3.12 If fish have to attempt passage through a culvert without the opportunity to rest immediately downstream, or have to continue strenuous swimming having just ascended a challenging culvert, they may become exhausted and be washed back downstream. A lack of rest areas and pools immediately upstream and downstream can thus render a difficult but theoretically passable culvert effectively impassable. Debris Accumulation 3.13 Blockage by debris and the downstream movement of river bed material can occur in small-diameter culverts and where trash screens or farm animal barriers are installed. While total blockage is unlikely, collection of debris can effectively prevent passage of large upstream migrants. Any blockage may cause local increases in current speed which may defeat fish of all sizes. Downstream migrating fish may also become trapped in debris blockages. Percolating Flow 3.14 Percolating flow through gabion mattresses and rip-rap can deplete the main flow or even cause the whole flow to pass through the gaps. This can prevent upstream passage but can be particularly harmful to downstream migrants, which may become stranded or trapped. Impassable Weirs 3.15 Weirs are sometimes installed immediately downstream of bridges, either at the same time as the bridge was constructed or at a later date, to prevent or reduce erosion of the bridge footings. While this is likely to make fish passage through the bridge area straightforward, the weir itself can be an impediment to migration. Construction Activities 3.16 Construction work and river diversions can cause temporary disruption of migration even if the permanent works are designed to allow fish passage. 1.1.1 PART 2 ASSESSMENT 4 ASSESSMENT PROCESS 4.1 The requirements for fish passage should be considered throughout the development of the road project. A step-by-step approach is provided in Figure 4.1 which shows the progression of proposals through a staged process leading to the conceptual design of the in-river structure. The procedure for integrating fish passage requirements within the development of the conceptual design is described in Chapter 6. Stage 1 4.2 As part of the initial assessment of the overall road improvement strategy the location of river and burn crossings should be considered and included in the review of options for positioning the road alignment to achieve a balance between broad engineering, cost and environmental considerations. The need for crossings should be confirmed through examination of broad alternatives for the route of the road. If possible, crossings of important watercourses should be avoided. This step should be considered as part of the constraints analysis in the Stage 1 environmental assessment process outlined in the DMRB. 4.3 Early consultation with SEPA, SNH and SERAD(1) is essential. Information obtained from consultation and initial site visits should be taken into account in considering the siting and justification for a stream crossing as part of the Stage 1 assessment. In assessing the requirement for fish passage facilities at a river crossing, it is important to consider any existing obstructions to fish passage nearby. There is little point in providing good conditions for migrating fish passage if the stream is impassable downstream or a short distance upstream due to a natural obstruction. Stage 2 4.4 In this stage further relevant data on the watercourse should be collated in order to identify the future requirements for the design of the structure. The hydrological data for the catchment are collated for later use in calculation purposes in Stage 3 and also to identify any significant flooding risks. Other considerations at this stage include identification of potential ground conditions for foundation design, investigating the potential to temporarily divert the watercourse so that the structure can be built "in the dry" and any specific access and maintenance requirements (e.g. for cattle, farm traffic etc). Consultations with relevant bodies (including the relevant DSFB (see Appendix A)) and, if appropriate, site surveys, should be undertaken to establish the need to accommodate particular fish species, in conjunction with other wildlife needs (for example, allowance for otter passage). 4.5 This step concludes with the comparison of options which have been identified and consideration of their relative costs in relation to the overall costs of the road improvement. These options could, for example, include a short culvert with a realigned watercourse, a long culvert on original line, a bridge, etc (see Figure 4.2). This review of options should contribute to the Stage 2 DMRB route option environmental assessment. Stage 3 4.6 The development of the conceptual design should be undertaken as part of the Stage 3 environmental assessment of the preferred option. For culverts this stage closely relates to that presented in the CIRIA Culvert Design Guide (1997) and firms up on the type and size of the in-river structure. The sizing is derived from the hydrological parameters gathered in Stage 2 by calculating the acceptable maximum headwater depth for flood flows. In terms of fish passage, the flow velocity and depth under typical conditions when the fish are running needs to be identified (see Section 5.5). Consultations should continue with relevant organisations to ensure the developing design takes adequate account of the requirements for fish passage. Scheme Procurement 4.7 With Design and Construct schemes it is necessary to complete sufficient development of the conceptual design to ensure that robust requirements can be included in the contract documentation. Development of the detailed design will be the responsibility of the appointed contractor. 4.8 For road projects which are not formally assessed using the 3-stage DMRB process, such as maintenance and minor improvement schemes, the principles of the staged process described above should be followed to ensure early consideration of fish passage requirements. (1) Contact the Inspector of Salmon and Freshwater Fisheries (ISFF) and The Freshwater Fisheries Laboratory, Pitlochry. 1.1.2 PART 3 DESIGN 5 DESIGN REQUIREMENTS FOR FISH PASSAGE Introduction 5.1 Consideration of the life history, migratory behaviour and swimming ability of various types and sizes of fish, together with a review of where fish passage problems have arisen, indicates that the following factors must be acceptable for successful fish passage: adequate depth of water at the time of passage; appropriate water velocity; adequate resting places above and below the structure; and no physical obstructions to passage. Discussion 5.2 Attention to the above design factors is only required where a culvert installation modifies the stream profile. If the preferred option is for a bridge or a large culvert with effective retention or re-creation of the stream channel features these considerations need not apply (see Chapter 6). 5.3 It is not necessary for installations to be passable to fish at all times. Most upstream migrations take place at flows well above the dry-weather (Q95) flow, and well below the peak discharges. Peaks of discharge are generally short-lived events in smaller watercourses and a short delay in passage periods need not be critical. 5.4 In planning fish passage facilities it is important to consider the range of flows over which conditions for fish passage are to be optimised - the "passage design flow range". Good passage conditions should be provided during the period when fish are migrating in a particular area. 5.5 The appropriate DSFB (2) or other fisheries experts can provide advice on the passage design flow range, as it will vary between sites and fish species. Generally, there will be a shorter window of time over which fish passage can occur in small streams than in larger ones. A suggested "passage design flow range" for checking for excessive velocity at high flows and inadequate water depth at low flows is that lying between the 10 percentile and 90 percentile of normal flows respectively (the flows which are exceeded 10% and 90% of the time). Design Criteria 5.6 The design criteria listed in Table 5.1 for river-crossing structures to enable successful salmonid passage have been determined from a combination of biological data and other guideline publications. Key references are included in a Technical Report which is available to accompany this guidance document. 5.7 Small fish are able to exploit boundary layers close to culvert walls, where the water velocity is significantly lower than that in the central section of the water flow. For this reason the criteria presented in Table 5.1 for brown trout are likely to allow passage for much of the time of smaller fish and weaker swimmers such as eel and lamprey. In most situations no special consideration of other species is necessary. However, where other species, especially smaller fish and weaker swimmers, are of specific conservation interest, more stringent design criteria may be justified. Such cases are beyond the scope of this document, and specialist advice should be sought. (2) Contact addresses for each DSFB are provided in Appendix A and a summary of the role of the DSFBs is included. Table 5.1 Design Criteria for Salmonids Notes Brown Trout 15cm Sea Trout 25cm to 50cm Salmon > 55cm Culvert Length <20m 1.25m/s 1.6m/s 2.5m/s Culvert Length 20-30m 1.0m/s 1.5m/s 2.0m/s Culvert Length >30m 0.8m/s 1.25m/s 1.75m/s 0.3m 0.3m 0.5m Maximum Water Velocity: a,b,c Minimum Diameter of Pipes Minimum Depth of Water d 0.1m 0.15m 0.3m Maximum Water Level Drop e 0.2m 0.3m 0.3m Trash Screen (minimum gap) f 0.05m 0.1m 0.2m Notes a) Mean velocity of cross-section (there will be areas of lower and higher velocity). b) The velocities for the shorter culverts approximate to the burst speed achievable by each species at 5ºC, and the velocities for culverts > 30m approximate to the cruising speed. c) These velocities should not be exceeded at any flow within the passage design flow range. d) Minimum depth acceptable at the lower end of the passage design flow range. e) Maximum drop at either intake or outlet. f) The minimum gap a fish can pass through will depend upon the size of the fish - these gaps are for typical large adults. Trash screens should be avoided whenever possible but if this is not possible a grid of sufficient size to allow fish passage should be used. 5.8 Resting areas immediately downstream of and upstream of the culvert are desirable with the requirements being: an area of water of adequate depth (at least 30cm for trout, 45cm for salmon); an area of deeper water with adequate cover for resting; rocks or overhanging vegetation; and moderate flow conditions (well within the cruising speed of the fish (3)). 5.9 Resting pools within the culvert are not recommended as they are likely to collect silt and debris and would be difficult to maintain. (3) See Table 5.1 (Note b). 6 DESIGN CONSIDERATIONS Introduction 6.1 This chapter introduces the steps for ensuring that fish passage considerations are integrated into the design process for in-river structures. Culvert Conceptual Design 6.2 It is recommended that the conceptual design of a culvert is carried out using the process described in the Culvert Design Guide (CIRIA, 1997). The guide identifies that the conceptual design takes into account the relevant importance of hydraulic, environmental, operational and economic performance criteria. If the Culvert Design Guide is used with the guidance set out below it will be possible to ensure that issues of fish passage are adequately addressed in the culvert design process. 6.3 During the earlier stages of the road project design, initial data will have been collated such as the fish species which may be affected, the passage design flow range, the design flood return period etc (see Chapter 4). At the initial stage of the conceptual design, calculations of trial sizes for the culvert barrel size will have been undertaken and various data collated including the design flow rate, gradient, barrel roughness and culvert length. 6.4 This is the stage when the designer must check that the predicted hydraulic conditions in the structure at critical times are appropriate for any fish species which will migrate through it (see Section 5.5). 6.5 The main parameters to be considered in the calculation of flow velocity and water depth are culvert slope, length and the Manning n value (roughness) for the culvert invert material being considered. These parameters together with the culvert size can be adjusted through iteration to develop an economical solution which allows both for fish passage and flood flow conditions. 6.6 The criteria which will allow the successful passage of fish are provided in Chapter 5. 6.7 The suggested approach is to review a number of alternative culvert designs and check which will ensure the free passage of fish. 6.8 The alternatives should be considered in the order listed below. If the basic culvert in Case 1 is found to be unsatisfactory for fish passage then the designer considers Case 2, etc until a satisfactory design is achieved. (i) Case 1: Culvert barrel with dimensions derived for the passage of flood flows. (ii) Case 2: Culvert with a depressed invert to allow the inclusion of stream bed material within the barrel. For circular and pipe arch culverts this will result in the specification of an increased diameter for the barrel. Similarly for rectangular shaped culverts the height of the box section will need to be increased to accommodate both flood flows and the bed material. (iii) Case 3: Provision of a bottomless arch culvert to retain the natural stream bed. (iv) Case 4: Provision of a low flow channel within the culvert invert, resulting in increased structural dimensions as identified in Case 2. (v) Case 5: Provision of baffles within the culvert (particularly appropriate for steeply sloping culverts), resulting in increased structural dimensions as identified in Case 2. 6.9 In Chapter 3 common problems which affect the passage of fish have been described. Other factors which will help avoid these problems and should be considered during conceptual culvert design include the following: (i) Matching culvert gradient with the stream gradient where possible to minimise changes in stream hydraulics which may affect fish passage. (ii) The provision of outlet pools as a means of raising tailwater levels and avoiding extensive erosion protection works at the outlet. These pools provide resting places for migratory fish prior to negotiating the culvert. Inlet resting pools may also be required in certain situations. (iii) When a multi-pipe structure is used ensure at least one barrel is set at sufficiently low level to ensure an adequate depth of water for fish passage under low flow conditions. (iv) Designing inverts to allow for both the free passage of fish and the passage of other animals (otters etc). (v) Maintaining appropriate conditions for fish passage through long culverts. (Long culverts do not in themselves represent an increased obstruction to fish as long as appropriate conditions for fish passage are maintained throughout.) Lack of light in a culvert does not appear to influence fish passage. (vi) The design of a trash screen (if this cannot be avoided) should ensure fish passage is not impeded. (vii) Approach conditions should be within the cruising ability of the fish in the watercourse. Bridges 6.10 The design of river bridges and their foundations should accord with BA 59/94 in Volume 2 of the DMRB. This gives advice in the consideration of scour protection of in-river piers and abutments. If the foundations are designed at an adequate depth to avoid scouring then it is unlikely that bridge aprons and weirs will be required and issues of fish passage will not be of concern. Where a bridge apron is unavoidable it should be designed to ensure an adequate depth of water to ensure fish passage is facilitated through the passage design flow range and to avoid the need for a control structure such as a weir downstream. In situations where a weir is unavoidable it is important to ensure that there is an adequate depth of water to facilitate fish passage in low flow conditions over at least part of it. Baffles may be necessary to reduce water velocity through any fish passage measure. General Design Principles to Minimise Construction Impacts to Fish 6.11 The following principles should be followed in the design process and contract preparation to ensure that construction impacts on fish are minimised. (i) Avoid in-river structures where possible to prevent scour and reduce the impacts of temporary works during construction which could affect fish passage. (ii) Where appropriate use a bridge in preference to a culvert to minimise impacts to free fish passage. (iii) Design all new in-river structures to avoid the necessity for retrofit measures. (iv) Wherever possible, schedule in-river works to minimise impacts to fish. (v) Ensure the detailed design is complete and construction process adequately planned before starting construction to reduce impacts on fish and other wildlife. (vi) Inspect culverts regularly during construction to ensure inlets and outlets are kept free from debris which could prevent fish passage. (vii) Explore the potential to restore the natural river banks at the end of construction and avoid the use of gabions and rip rap where possible to ensure that shelter at the bankside is retained for fish. (viii) Use of rip rap or boulders for erosion protection is preferred to gabion baskets which may harm fish if they become damaged (and also results in lower maintenance liabilities). (ix) Remove all redundant in-stream works where these affect fish passage unless such action would cause other significant environmental damage or where cost would be prohibitive. (ix) If a stream requires realignment as part of the works, consideration should be given to provision of straight lengths upstream and downstream of the structure to reduce the need for extensive erosion protection works which may be detrimental to fish passage. Other Issues 6.12 As well as guidance contained in this report other general best practice guidance, such as SEPA Best Management Practices, should also be implemented during construction. 6.13 The risk of disturbance to and pollution of watercourses should be minimised during the construction process by careful control of site run-off, chemicals and fuels. 6.14 Maintenance issues should be considered at an early stage in collating contract requirements. Requirements for timing and form of maintenance should be discussed with SNH and DSFBs during consultations. For example, it may be necessary to include a maintenance requirement to clean trash screens prior to fish runs to that ensure that these do not obstruct fish passage. 1.1.3 7 IMPROVEMENT AT EXISTING PROBLEM SITES Introduction 7.1 Many existing river crossings present significant or even total obstacles to fish migration, restricting the overall productivity of the river system. This chapter examines the process of evaluating, planning and executing improvements. Assessment of the Extent of the Existing Problem 7.2 A complete bar to migration is more serious than an obstruction that lets some fish through on occasions. Visual inspection by an appropriate expert will immediately indicate that some crossings are probably a complete barrier while others are likely to represent no hindrance to all. It is important that the level of barrier represented by those that fall between these two extremes is carefully evaluated. Obstructions which appear severe, and indeed may represent a major delay or hindrance to migration under some conditions, may not warrant remedial action if surveys show that stocks of juvenile salmon and trout are routinely present upstream. Assessment of Responsibilities 7.3 The approval of the Roads Authority is required for proposed works to any ditch, watercourse, bridge, culvert, tunnel or pipe constructed, laid or erected by the Roads Authority for the purpose of draining a road. Options for Amelioration 7.4 Options for introducing measures to assist fish passage should be identified based on local topographical constraints, hydraulic considerations and cost effectiveness. Relatively low cost measures can be effective in many cases. Complete rebuild, using sound design principles to ensure that the new installation provides good fish passage conditions (see Chapters 5 and 6) may be the only viable option for extreme problems. Culverts 7.5 There are two approaches to tackling the problem of excessive water velocity and both can help ameliorate the problem of water being too shallow for effective fish passage: (i) reduce the velocity throughout the section of the flow by increasing the depth of water through the installation of one or more additional structures; (ii) introduce some roughness to the bed of the culvert causing local lowering of current speed and thus leading to some increase in water depth. 7.6 In evaluating these options consideration should be given to the effective reduction in flow capacity of the culvert and the significance of increased water levels upstream. Weirs at Culvert Outlets 7.7 An effective approach to deepening the water and slowing the flow is to raise the tailwater level by installing a weir downstream of the culvert outlet, backing up the water through the culvert itself. Installation and maintenance are easier in the open, and there is no requirement to attach any structure to the fabric of the culvert. This approach can also ameliorate any perching problem. 7.8 Several North American reports present guidelines for the design of low stone weir installations intended to raise tailwater height. It is recommended that weirs should be a minimum of 6m apart and have a maximum fall of 30 cm between successive weir crests, and that the most downstream structure should have its crest level with the stream bed to act as an erosion control mechanism (see Figure 7.1). Baffles 7.9 The shape and orientation of baffles depends on the culvert barrel shape and its gradient. The recommended solutions, based on recent research are shown in Figures 7.2 and 7.3. Increasing Bed Roughness 7.10 A simple low-cost approach to increasing bed roughness has been applied in a number of streams in Montana, USA. This involves installation of a pre-fabricated steel frame rather like a ladder which lies along the bed of the culvert. It can be constructed in 6 metre long sections for transport to site, and the cross-bars or "rungs" are fixed at 1200mm intervals (see Figure 7.4). 7.11 After installation an average of three "large" rocks are placed against, and are therefore anchored by each cross-member. The rocks thus provide the turbulence and depth to allow fish to migrate. Bridges 7.12 Bridges generally represent much more benign conditions for fish passage than culverts. The main potential for problems is with bridge aprons or sills, installed either when the bridge was constructed or retro-fitted to correct erosion that potentially threatens the bridge structure. These can be perched in the same manner as culverts, making it difficult or impossible for fish to ascend at certain flows. Flat bridge aprons can also present problems for fish passage at low flows as the available water is spread very thinly over the width of the channel. 7.13 The most straightforward solution to perching at bridge aprons is the installation of low stone weirs as described in Sections 7.8 and 7.9. This approach may also be appropriate to overcome inadequate water depth problems on the apron itself. An alternative approach would be to re-cast the apron into a v-shaped channel so that the flow is concentrated in the centre. This creates shallow slow-moving water at the edges which will ease the passage of smaller fish, while providing a deeper zone for larger fish in the centre. Alternatively the lip of aprons can be broken down or baffles or boulders used on the apron to channel low flows. Fords 7.14 The simplest solution to the inadequate water depth problem at fords is to install a pipe or culvert to carry low flows beneath the roadway, allowing the high flows to pass over the roadway. The culvert can be much smaller than would be required if flood flows had to be conveyed, but it should not be below 30 cm diameter for trout passage or 45 cm diameter for salmon passage. Such small diameter pipes are vulnerable to blockage by debris so regular inspection and maintenance may be required. Pipes installed beneath natural bed level will also be subject to blockage through siltation. Weirs 7.15 Weirs have often been installed immediately downstream of road bridges to prevent erosion of the bridge foundations. Whilst making the bridge itself readily passable to fish the weir may represent a major or even total obstruction. There are two approaches to alleviating this problem. The first is to raise the tailwater level of the weir using a series of further stone weirs (as described in Sections 7.8 and 7.9). The second is to install a fish pass in the weir. Design of fish passes should be made with reference to the guidelines published by SOAFD (1995). 1.1.4 REFERENCES CIRIA (Construction Industry Research and Information). 1997. Culvert Design Guide. Report 168. CIRIA, London. Department of Transport/Scottish Office Industry Department/Welsh Office/Department of the Environment for Northern Ireland. 1993. Design Manual for Roads and Bridges. HMSO, London. SEPA (Scottish Environment Protection Agency). 1996. A Guide to Surface Water Best Management Practices. SOAFD (Scottish Office Agriculture and Fisheries Department). 1995. Notes for Guidance on the Provision of Fish Passes and Screens for the Safe Passage of Salmon. Apron 1.1.5 GLOSSARY Erosion protection replacing or reinforcing stream bed in an area of high velocity flow such as downstream of a culvert. Baffle Obstruction, usually wood, concrete, or metal placed inside a culvert to deflect and check the flow of water. Burst Speed The highest rate of speed a fish can generate for a short period of time (such as several seconds). Cruising Speed The speed at which a fish can swim indefinitely. Debris See trash. Design Discharge A quantity (rate) of flow that is expected at a certain point as a result of a design storm or a specific low flow condition. Usually expressed as a rate of flow in metres3 per second. Fish Migration The movement of individual fish and/or fish populations for any purpose, including feeding, spawning, etc. Ford A road crossing a stream where a hard causeway is provided in the bed of the stream. Fry Juvenile salmon and trout in their first few months of life. Gabion A patented woven or welded wire basket filled with rocks of such a size that they do not pass through the openings in the basket. Individual baskets are stacked in place like building blocks and filled with rock to form erosion resistant structures. Gradient (slope) The rate of rise or fall of a slope - expressed as a percentage or ratio as determined by a change in elevation to the length. Inlet Entry point to a culvert. Invert The lowest internal point of any cross section in a culvert. Manning's An equation for determining the quantity of flow whose factors are the Formula or hydraulic radius, cross section area of flow, and a coefficient of Equation roughness, Manning's n. Outlet Exit point from a culvert. Parr Juvenile salmonids between the fry and smolt stages. Passage The flow range used in assessing fish passage parameters. Design Flow Range Peak Flow The maximum instantaneous rate of flow during a flood. Perching The development of a fall or cascade at a culvert outlet due to the erosion of the stream channel downstream from a culvert barrel, bridge apron or ford. Pipe Arch Multi-plate or structural plate culverts assembled on a treated timber or concrete foundation. Because of their size (normally in excess of 2 m in diameter) and the fact they are placed on a foundation, they are normally assembled on site. A series of interlocking steel plates are bolted together to make the required shape and length. Many older pipe arches have been formed using brick. Return Period A statistical term defining the probability of occurrence of an (in years) event. Thus a 1-in-50 year return period flood (also referred to as the 50 year flood) is one likely to be equalled or exceeded only once on average in a 50-year period. Salmonid Any of the fish belonging to the family Salmonidae such as salmon and trout. Scour Term used to describe soil erosion when it occurs underwater as in the case of a stream bottom or bank. Smolt The juvenile downstream migrant stage of salmon and sea trout. Trash Any buoyant or semi-buoyant material carried by the flow of water in a channel but which could form a blockage in a culvert. Also referred to as debris. Weir Small dam in a stream that causes water to back up behind it, and flow over or through it. 1.1.6 APPENDIX A DISTRICT SALMON FISHERY BOARDS In Scotland, the day to day responsibility for enforcing salmon fisheries regulations rests with District Salmon Fishery Boards. Where a District Salmon Fishery Board is formed it must be in accordance with the terms of the Salmon Act 1986. Members of the board comprise proprietors of fishing rights in the district, or their mandatories, and co-opted representatives of anglers and tenant netsmen where appropriate. Proprietors are designated as upper or lower proprietors according to the location of their fisheries and the members of the board who are proprietors are elected from these two constituencies. The chairman, who must be a proprietor, is elected by the whole board, i.e. proprietors and co-optees. In many cases, boards invite representatives from SNH and SEPA to attend their meetings. Where District Salmon Fishery Boards are formed they have statutory duties and powers under the Salmon Act 1986. Although they are not statutory consultees they should always be consulted regarding works that may affect watercourses or fisheries. A Board has duties to appoint a Clerk, maintain a roll of upper and lower proprietors, prepare an annual report, hold an annual meeting, and call triennial elections. Boards have powers to do such acts, execute such works and incur such expenses as seem to them expedient for the protection or improvement of salmon within their districts, for the increase of salmon, and for the stocking of waters of their districts with salmon. Each Board also has powers to appoint water bailiffs, sue in the name of the clerk, impose an assessment on each salmon fishery in its district, charge interest on arrears of assessments, borrow money, and exempt persons from certain provisions of the law for scientific and other purposes. 1.1.7 1. ANNAN CLERKS TO THE DISTRICT SALMON FISHERY BOARDS Ms C A K Rafferty Per Messrs McJerrow & Stevenson Solicitors 55 High Street Lockerbie Dumfriesshire DG11 2JJ (01576 202123-4) 2. AWE T C MacNair Esq Per Messrs MacArthur Stewart & Co Solicitors Boswell House Argyll Square Oban PA34 4BD (01631 562215) 3. AYR F M Watson Esq D W Shaw & Company Solicitors 34a Sandgate Ayr KA7 1BG (01292) 265033 4. BEAULY J Wotherspoon Esq MacAndrew & Jenkins WS Solicitors & Estate Agents 5 Drummond Street INVERNESS IV1 1QF (01463 233001) 5. BLADNOCH Peter M Murray Esq Per Messrs A B & A Matthews Bank of Scotland Buildings Newton Stewart DG8 6EG (01671 404100) 6. BROOM Mr G C Muirden Per Messrs Middleton Ross & Arnot Solicitors PO Box No 8 Mansefield House Dingwall Ross-shire IV15 9HJ (01349 862214) (Fax 863819) 7. BRORA C J Whealing Esq Sutherland Estates Office Duke Street Golspie Sutherland KW10 6RR (01408 633268) 8. CAITHNESS P J W Blackwood Esq Estate Office Thurso East Thurso Caithness KW14 8HW (01847 63134) 9. CONON E M B Larby Esq SALMON FISHERY DISTRICT Finlayson Hughes 45 Church Street Inverness IV1 1DR (01463 224343) 10. CREE Peter Murray Esq Per Messrs AB & A Matthews Solicitors Bank of Scotland Buildings Newton Stewart DG8 6EG (01671 3013) 11. CRERAN Lady Stewart Salachail Appin Argyll PA38 4BJ 12. DEE (ABERDEEN) George Alpine Esq per Messrs Paull & Williamsons Solicitors Investment House 6 Union Row Aberdeen AB9 8DQ (01224 621621) 13. DEE G S Scott Esq (KIRKCUDBRIGHT) Messrs Gillespie, Gifford & Brown 27 St Cuthbert Street Kirkcudbright DG6 4DJ (01557 330539) 14. DEVERON John A Christie Esq Murdoch, McMath & Mitchell 27/29 Duke Street Huntly Aberdeenshire AB54 5DP (01466 792291) 15. DON George Alpine Esq Per Messrs Paull & Williamsons Solicitors Investment House 6 Union Row Aberdeen AB9 8DQ (01224 621621) 16. DOON A M Thomson Esq 23 Wellington Square Ayr KA7 1HG (01292 266900) 17. EACHAIG Robert C G Teasdale Quarry Cottage Esq Rashfield By Dunoon Argyll PA23 8QT (01369 84510) 18. EAST LEWIS/LOCH ROAG George H MacDonald Estate Office Esq North Uist Estate Lochmaddy North Uist HS6 5AA (01876 500329) 19. ESK John Scott Esq Scott Alexander 46 High Street Montrose DD10 8JF (01674 671477) 20. EWE G C Muirden Esq Per Messrs Middleton, Ross & Arnot Solicitors PO Box No 8 Mansefield House Dingwall Ross-shire IV15 9HJ (01349 862214) (Fax 863819) 21. FINDHORN Sir William Gordon Cumming Altyre House Altyre By Forres Moray 22. FLEET C R Graves Esq Carse of Trostrie Twynholm Kirkcudbright DG6 4PS (01557 860618) 23. FORTH Mr T McKenzie 12 Charles Street Dunblane FK15 9BY (01786 825544) 24. GIRVAN S B Sheddon Esq Messrs James Smith & Valentine Solicitors & Estate Agents 16 Hamilton Street Girvan Ayrshire KA26 9EY (01465 713476) 25. HALLADALE G D Robertson Young Robertson & Co 29 Traill Street Thurso Caithness KW14 8EQ (01847 893247) 26. HARRIS G A Macdonald The Estate Office Lochmaddy North Uist HS6 5AA (01876 500428) 27. HELMSDALE Mr N Wright Arthur & Carmichael Cathedral Square Dornoch (01862 810202) 28. IORSA (ARRAN) J W Perkins 'Ramera' Sannox Isle of Arran KA27 8JD (01770 810671) 29. KANAIRD T Dixon Esq Carter Jonas CS 22 Broad Street Hereford HR4 9AP 30. KINLOCH A Sykes Esq Per Messrs Brodies WS 15 Atholl Crescent Edinburgh EH3 8HA (0131 228 4111) 31. KYLE OF SUTHERLAND J Mason Esq Bell Ingram Ltd Estates Office Bonar Bridge Sutherland IV24 3EA 32. LAGGAN & SORN R I G Ferguson Esq Per Messrs Stewart, Balfour & Sutherland 2 Castlehill Campbeltown Argyll PA28 6AW (01586 553737) 33. THE Malcolm Spence QC LOCHABER SALMON FISHERY DISTRICT] 2 Gray's Inn Gray's Inn LONDON WC1R 5JH 34. LOCH FYNE P M Fairweather Esq Cherry Park Inveraray Argyll PA32 8XE (01499 302203) 35. LOSSIE Mr A McCartan Messrs Andrew McCartan & Co Solicitors 145 High Street Forres Moray (01309 675259) 36. LUCE E A Fleming-Smith Esq Stair Estates Estate Office Rephad Stranraer Wigtownshire DG9 8BX (01776 2024) 37. MULLANAGEARAN Mr George MacDonald Estate Office Lochmaddy North Uist (01876 3324) 38. NAIRN E M B Larby Esq Finlayson Hughes 45 Church Street Inverness IV1 1DR 39. NAVER AND BORGIE Norman Wright Messrs Arthur & Carmichael Cathedral Square Dornoch Sutherland IV25 3SW 40. NESS F Kelly Esq Per Messrs Anderson Shaw & Gilbert Solicitors York House 20 Church Street Inverness IV1 1ED (01463 236123) 41. NITH R Styles Esq Walker and Sharp Solicitors 37 George Street Dumfries DG1 1EB (01387 267222) 42. THE NORTH A R Whitfield AND WEST SALMON FISHERY DISTRICT The Estate Office Achfary By LAIRG Sutherland IV27 4BQ 43. RUEL J Ferguson Esq 6 The Strand Rye East Sussex TN31 7DB (01797 222601) 44. SKYE P Butler Esq Mile End House Glen Hinnisdal Snizort Isle of Skye IV51 9UX (01470 542331) 45. SPEY C D R Whittle Esq Per Messrs R & R Urquhart 121 High Street Forres Morayshire IV36 0AB (013096 72216) 46. STINCHAR Mrs A McGinnis 'Thistles' 6 The Avenue Barr Nr Girvan Ayrshire KA26 9TX 47. TAY R P J Blake Esq Per Messrs Condies Solicitors 2 Tay Street Perth PH1 5LJ (01738 440088) 48. TWEED Mrs J Nicol River Tweed Commissioners The North Court Drygrange Steading By Melrose Roxburghshire TD6 9DJ (01896 848294) (Fax 01896 848277) 49. UGIE B Milton Esq 50. URR Masson & Glennie Solicitors Broad House Broad Street PETERHEAD AB42 6JA (01779 74271) Primrose & Gordon Solicitors & Estate Agents 92 Irish Street Dumfries DG1 2PF (01387 267316) 51. YTHAN M H T Andrew Esq 1.1.8 Estate Office Mains of Haddo Tarves, Ellon Aberdeenshire AB41 0LD (01651 851664) ACKNOWLEDGEMENTS Steering Group: Phil Gilmour, Amanda Chisholm, James Ellaway (Scottish Executive Development Department) David Dunkley, Ross Gardiner, Ian Phillips (Scottish Executive Rural Affairs Department) Lt Col Dougie Keelan, Judith Nicol (Association of District Salmon Fishery Boards) Steve Wallace (Carl Bro Group) Annie Say (ERM) David Solomon (Consultant, Salmon and Freshwater Fisheries) Consultees: District Salmon Fishery Boards (DSFB) Annan DSFB Bladnoch DSFB Brora DSFB Conon & Nairn DSFB Cree DSFB Dee DSFB (Aberdeen) Dee DSFB (Kirkcudbright) Don DSFB Doon DSFB Eachaig DSFB Ewe DSFB Forth DSFB Grudie & Dionard DSFB Helmsdale DSFB Kyle of Sutherland DSFB Laxford DSFB Loch Fyne DSFB Loch Inchard DSFB Loch Shiel DSFB Lochy DSFB Morar DSFB Naver and Borgie DSFB Ness DSFB Nith DSFB Spey DSFB Tay DSFB Ythan DSFB Local Authorities: Aberdeenshire Council Angus Council Argyll and Bute Council City of Glasgow Council Clackmannanshire Council East Ayrshire Council East Renfrewshire Council Inverclyde Council Midlothian Council Moray Council North Ayrshire Council North Lanarkshire Council Perth and Kinross Council Renfrewshire Council Scottish Borders Council South Ayrshire Council South Lanarkshire Council Stirling Council West Lothian Council Others: Atlantic Salmon Trust Ltd Babtie Group Colin Carnie Countryside Commission Countryside Commission for Wales English Nature Environment Agency Fairhurst and Partners Fishwyse Forest Enterprise _ Forest Civil Engineering Game Conservancy Council Highways Agency Institution of Freshwater Ecology Institution of Highways and Transportation Institution of Structural Engineers Ironside Farrar Joint Nature Conservation Committee Kincardine Estate M6 Joint Venture Powys Engineering Consultancy Services Rivers Agency Scottish Anglers National Association Scottish Hydro Electric Scottish Natural Heritage Scottish Wildlife Trust SEPA The Game Conservancy Trust Turnbull Jeffrey Partnership Tweed Foundation COMMENTS ON THIS DOCUMENT This document is being circulated as a Consultation Paper subject to a twelve-month consultation period. Feedback on the application of the approach detailed in the document, together with suggestions for improvements, should be made by 31st March 2001 to: Amanda Chisholm - Environmental Advisor Trunk Roads - Design and Construction Division Scottish Executive Development Department Victoria Quay, Edinburgh EH6 6QQ Tel: 0131 244 7225 Fax: 0131 244 7228 Email: amanda.chisholm@scotland.gov.uk