Aquatic Habitat Rehabilitation Plan
Summary of Issues Identified from Geomorphic Assessments
Aggradation was often identified as the dominant geomorphic process, both in general and in areas of instability, so restoration efforts should focus on reducing sediment sources. Sources of sediment originate along unstable stream banks and degrading stream beds. Stream bank erosion is often a natural process that provides a source of boulders, cobble and gravel for fish habitat. However, when natural levels of erosion are exceeded, fish habitat may be lost and the stream and riparian zone may have difficulty recovering. If landslides/bank failures along a channel are widespread, this is an indication of increased destabilizing processes, such as altered runoff rates. Treatments may not have a reasonable chance of success in these cases and it may not be worthwhile to install localized bank treatments. However, if there are relatively few isolated bank erosion problems, it is probably feasible to stabilize eroding banks. This can be accomplished via a variety of methods using boulder and log structures, revegetation, and removal or relocation of obstructions that are deflecting flow into unstable banks.
Reach 1: Rt 114 to where Mechanic Lake Brook joins the Pollett (Sub-reaches MLB 2 1 to 2 28)
Gordon Falls, located in Reach 3, quite some distance below, may be a permanent natural barrier to upstream migration of Salmon into this reach (Elson 1962). As a consequence any activities planned within it should be conducted with that fact in mind when determining how much of a priority they are as compared to those below Gordon Falls. That said, sediment eroded from this reach, can influence conditions downstream.
Identification and control of the sediment sources in this reach should precede any in-stream restoration efforts. Otherwise, the excessive amount of sediments in the system could end up burying installed structures. Possible sources of sediment could be from eroding banks or mobile bed materials, poorly vegetated upslope areas, poorly constructed roads, and poorly managed timber harvests. It has been noted that a large amount of crown timberland and woodland as well as private woodlots exist in the surrounding watershed (GeoNB mapping service). It is important that harvesting activities adhere to existing legislation so that buffer zones maintain their function. The lack of good buffer or riparian zones adjacent to watercourses could lead to increased runoff and larger peak flows. More intense flows have more erosive energy and thus greater potential to carry more sediment. Another potential anthropogenic source of sediment would be at poorly installed stream crossings. Improperly sized or misaligned woods road culverts can lead to erosion of road berms or even road washouts in extreme cases. It would be prudent to ensure that buffer zones and stream crossings on the assessed length of stream and its associated tributaries are in good condition.
Given the many water crossings shown on the tributaries of this reach in Figure 3-7, it is likely to be worth conducting a more systematic inventory of some or all them to assess their condition. While conducting fieldwork work in 2009, The Petitcodiac Watershed Alliance noted excessive sediment load in a tributary of the Pollett that was a consequence of poor culvert installation on a logging road and brought it to the attention of J.D. Irving (Petitcodiac Watershed Alliance 2009). It seems unlikely that this was an isolated situation. In the short term, such a survey is probably the primary activity worth undertaking within this reach. Along it are 14 unpaved and 2 paved water crossings. It is worth noting that above this reach, upstream of Mechanic lake are an additional 4 unpaved and 3 paved crossings, and on another tributary stream an additional 10 unpaved and 2 paved crossings. In reach 2 and the first part of reach 3 are numerous others. Altogether 53 out of the 94 unpaved crossings and 8 of the 47 paved crossings within the watershed are located above Gordon Falls.
Reach 2: Start of Pollett to Churchs Corner (Sub-reaches PS 3 1 to PS 3 44 & PS 2 1 to PS 2 5)
Like Reach 1, this reach is also entirely above Gordon Falls, so with regards to Salmon habitat the level of priority assigned to projects within it should be regarded with that context in mind. As with the previous reach, identification and control of the sediment sources in this reach should be the first step towards any restoration efforts. It contains 13 unpaved water crossings and no paved ones.
Reach 3 Part 1: Churchs Corner to below Elgin near Rt 895 (Sub-reaches PS 2 6 to PS 2 38)
The first portions of this reach (PS 2 6 to PS 2 22) are above Gordon Falls and subject to the conditions noted in reaches 1 and 2. Additionally, any restoration efforts attempted in the upper sub-reaches of this section should take consideration the very shallow depth to bedrock, where the bedrock often makes up the channel bed and/or banks. In this case, anchoring in-stream or bank stabilization structures will be more difficult compared to areas with a well-established soil layer. Another consideration is the presence of aggradation causing instability in the first sub-reach and immediately upstream of the first sub-reach. This would have to be addressed prior to commencing any in stream works downstream; otherwise the effectiveness of the work could be compromised if the sediments in the upstream sections migrate downstream.
The lower sub-reaches of this section, downstream of the waterfalls, are accessible by salmon, and thus warrant higher priority for work than those above them. These reaches are mostly experiencing instability due to an increase in the bedload as illustrated in Figure 3-31 and Figure 3-32. Restoration efforts should focus on locating the source of the sediment and implementation of strategies such as re-establishment of vegetation via changing land use practises, or bank treatments such as seeding, planting, or possibly slope regrading if banks are severely eroded. Given the large number of land owners in and around Elgin, significant outreach is necessary to identify individuals interested in and capable of undertaking such projects.
Much of the infrastructure for this is already in place in the form of the Pollett River Watershed Project (PRWP). It is an initiative of the Greater Fundy Ecosystem Research Group (GFE) to encourage conservation on private woodlots. Their partner organizations in the project are the Southern New Brunswick Wood Coop (SNB), the Fundy Model Forest, the Kendall Foundation, and numerous private woodlot owners, clustered primarily around Elgin (Steeves et. al 2007). They already have established a Watershed Management Plan for the Pollett River (Betts et al. 2002) that among other things examines and encourages water course buffers in relation to timber harvesting. As noted in Figure 3-33 there is significant aggradation immediately downstream of Elgin. Identifying partners amongst these land owners who are willing to undertake projects to improve buffer zones in this section of river as well as in adjoining tributaries will help meet the need for identification and control of the sediment sources. With regards to water crossings within this reach, there are 18 unpaved (6 of which are above Gordon Falls) and 13 paved (4 of which are above Gordon Falls).
Reach 3, Part 2: Below Elgin near Rt 895 to Parkindale Bridge (Sub-reaches PS 2 39 to PS 2 67)
Unstable sub-reaches should be handled appropriately as outlined in previous sections, whether by mitigating erosive forces with stabilization of the grade and/or providing floodplain access for degrading sections or identifying and controlling sediment sources for aggrading reaches. There are 21 unpaved water crossings in this reach, and 16 paved ones. As noted in reach 3 part 1 the large number of small land owners creates some complexity, but also opportunity for partnerships. Additionally the fact that this portion of the river is accessible to salmon makes projects here a higher priority than further upstream.
Other in-stream work here could include channel restoration along widening sub-reaches and should be designed to narrow the channel by accumulating sediments towards the banks. The benefits of channel restoration are: reduced erosion rates, improved water quality and aquatic habitat, increased food web productivity, and overall improvement of the aquatic ecosystem. Examples of potential projects are brush matting, upstream-V log weirs, and double tree deflectors. Brush mats promote sediment accumulation on point bars and help to narrow and stabilize the stream channel. Upstream-V log weirs are used to scour pools on the downstream side and accumulate gravel on the upstream side. They also direct flows away from the banks, narrow the stream channel and can provide better access to the floodplain. Like the Upstream-V log weir, double tree deflectors are designed to narrow the channel and concentrate flows near the center. They also promote sediment deposition and provide habitat diversity. However care would need to be taken to ensure that such in-stream structures intended to improve stream habitats do not create scour along banks, particularly where the channel is also experiencing degradation. Log wing deflectors provide one means of directing flow away from an unstable bank and holding soil in place. It would also be important to be aware of recreational users along the Pollett in this portion of the river in particular as it experiences significant traffic, particularly during the Pollett River Run. In-stream projects here must be designed and constructed to avoid creating hazards, either real or perceived ones.
Reach 3, Part 3: Above Parkindale Bridge to The Glades (Sub-reaches PS 2 68 to PS 2 95)
In terms of interventions, there is little to distinguish this portion of the river from reach 3 part 2 immediately upstream. Once again, sediment sources need to be identified and controlled prior to installation of any in-stream structures so as to not jeopardize the work. There are 11 unpaved water crossings and 7 paved crossings. This is the bottom portion of the Pollett River Run, with most participants exiting the river along this reach. Pollett River Run debris is also significant along this section, and it will be part of the 2014 clean up. Fewer of the landowners along this section are participants in the Pollett River Watershed Project, which suggests that there may be less opportunity here for partnership on projects, or in the very least a need for more outreach, as the distance from Elgin could be a factor.
Reach 3, Part 4: The Glades to confluence with Petitcodiac (Sub-reaches PS 2 96 to PS 2 125)
Along this section there are 3 unpaved crossings and six paved crossings. Being at or near the mouth of the river, these lower sub-reaches have wider channel widths and lower grade. That being the case, they are natural areas of deposition for sediments being carried down from upper reaches. Like the reaches immediately upstream there are few participating land owners in the Pollett River Watershed Project along this portion of the river, so additional public outreach in these communities will likely be required.
Restoration Activities Undertaken
Pollett River Run Clean up
Significant quantities of debris were in the river from Reach 3 Part 2 on downstream as a consequence of the Pollett River Run which occurs here each year the last weekend in April. Participants launch homemade boats in the midst of the spring freshet, and encouraged by a bit of alcohol, try their luck on the river. As a consequence numerous bits and pieces of wrecked boats are typically scattered along the river. The debris left behind is a hazard or at very least an eyesore for all other river users. In 2014 Fort Folly Habitat Recovery conducted a clean-up of River Run debris along the Pollett. The timeline; map of areas affected (Figure 3-44); debris photos (Figure 3-45); and debris removed (Table 3-3) are listed below.
April 26, 2014 – Pollett River Run took place.
May 6, 2014 – Installation of Pollett River smolt wheel. From this point we were collecting flotsam, presumably washed down from the River Run. Garbage collected was stored at nearby gravel quarry.
May 15, 2014 – Upper fyke net installed. Vigilance required to stop flotsam from damaging equipment
May 21, 2014 – Barrier fence erected. Barrier fence was knocked down by an abandoned raft in 2013.
June 9, 2014 – Last day of fishing smolt wheel
June 10, 2014 – FFHR crew canoed River Run length, picked up small garbage, assessed abandoned rafts to determine methods and tools needed to dislodge and then float rafts to access points such as bridges, old trails and camps where the garbage can be loaded onto pickup trucks for removal.
June 17, 2014 –FFHR & PWA crews using 2 canoes float from Beaman pool to the smolt wheel site. Noted large debris sites, assessed abandoned rafts, and picked up smaller garbage along the way
June 18, 20, 25, 27, 2014 – Using canoes, the 5 person FFHR, PWA team dislodged and floated large debris, mainly abandoned rafts to access points for removal.
June 19, 23, 24, 2014 – FFHR crew, used canoes continue to collect garbage from the river and move to temporary dump site.
June 26, July 2, 3, 4, 2014 – FFHR crew used hand tools, come along and chain saw to dismantle rafts and load pieces for removal to temporary dump site.
July 7, 8, 9, 2014 – FFHR crew conduct final inspection and litter clean up with canoes. Cover the entire length from Elgin to the mouth of the Pollett, and then continue down the Petitcodiac to the head of tide at Salisbury.
November 14, 17, 18, 19, 2014– FFHR crew sort debris, separating construction material from landfill garbage. Debris taken to local solid waste facility. Total of 2,170 kg removed.
Figure 3-44: Pollett River Run, and extent of area cleaned it its aftermath in 2014
Table 3-3: Pollett River Run Debris Clean up in 2014
Table 3-3: Pollett River Run Debris Clean up in 2014
Debris cleared from culverts
During the course of the 2014 culvert surveys, several candidates were identified for immediate action. Removing debris build-up is a simple and effective way of improving fish passage. All four debris removals were completed in the Pollett River basin. The first removal effort was conducted at the inflow of Culvert C012 (Figure 3-9) on Colpitts Brook. In order to improve fish access to approximately 7 km of upstream habitat in length and 31.43 km² in area, 3 trees were removed and placed above the high water mark (Figure 3-46).
Figure 3-46: Before and after photos of C012, located where Kaye Road crosses Colpitts Brook.
A second debris removal took place upstream of triple culvert C021-ABC, where willow growth had choked off the watercourse to the extent that it was scarcely visible (Figure 3-47). Willows were removed to enable fish passage to 6 km in length and 12.42 km² of upstream habitat
Figure 3-47: Before and after photos of culvert C021-ABC, where Church Hill Road intercepts Sheffer Brook.
The third debris removal took place at culvert C022-ABC approximately 3 kilometers upstream of triple culvert C021-ABC. Debris build-up was removed from the inflow of the middle culvert (Figure 3-48), allowing fish improved access to 9.27 km² of upstream habitat.
Figure 3-48: Before and after photos of C022-ABC, located where Church Hill Road intercepts Sheffer Brook
Two large trees were removed from the inflow of culvert C041, located where an Irving logging road intercepts the Popple-Intervale Brook. 7 km in length and 27.23 km² of upstream habitat was made more accessible for aquatic species.
Figure 3-49: Before and after photos of C041, where an Irving logging road crosses the Popple Intervale Brook.
Van De Brand Property
Anthony and Wanda Van De Brand own a farm, located at the mouth of the Pollett (Figure 3-50), which had a streambank that was experiencing significant erosion and threatening a cultivated field. That site, located in Reach 3, Part 4 was defined over all as “in regime” (Figure 3-41). The primary geomorphic process there is aggradation (Figure 3-42), and the secondary geomorphic process is degradation (Figure 3-43). Figure 3-51 illustrates the erosion occurring on the site prior to intervention.
Figure 3-50: Location of Van de Brand project
Figure 3-51: Site prior to stream bank stabilization
Initially 25 tonnes of large rock were installed at the site (Figure 3-52). That was not intended to be the full project, though, the results of this initial were briefly monitored, prior to proceeding. It became clear that erosion was continuing and so prior to final planting, additional rock was required. A total of an additional 100 tons of smaller rock was then added to the site (Figure 3-53), after which 100 Silver Maples and 4,000 live willow stakes were planted.
Figure 3-52: First riprap installation
Figure 3-53: Second riprap installation, and planting with silver maples, and willow live stakes
Opportunities for Future Restoration Activities
The 2014 Pollett River Run debris clean-up was deemed to have been a worthwhile activity, not just in terms of protecting research equipment such as the fyke nets, smolt wheel, and fish net trap downstream, but also in terms of improved state of the river itself. In 2015 Fort Folly Habitat Recovery and the Petitcodiac Watershed Alliance will be cooperating to raise awareness during the Pollett River Run, encouraging participants to reduce their impacts and remove their own debris. Public Service Announcements will be run on Radio Station XL 96 prior to the event. A dumpster will be provided at take out location at the end of the run, and one or more canoes will be in the river, participating in the run itself. After the run there will no doubt still be debris in the river to be cleaned up and a process like the work done in 2014 will be implemented. This will likely become an annual activity.
Beyond that, identification of sources of sediment within the watershed is an important first step in order to develop further priorities for specific action. As a result of the geomorphic work the in-stream sources of sediment from reaches experiencing degradation along the main stem of the Pollett are now known. Completion of the inventory of water crossings, particularly in the upper reaches of the watershed where the majority (77%) of the crossings of tributaries are unpaved would be a useful addition to that. There are 62 water crossings that have been identified in the GIS layer that have not yet been assessed. Due to equipment constraints, (need for ATV) 37 of these were not located either because they were deemed inaccessible, or in some cases they may not have been found because they do not exist, possibly identified in error due to errors in the road and water layers of the GIS. There was not an attempt in 2014 to locate the other 25. So completion of the survey (with an ATV) would be useful in order to fine tune the list and properly rank priorities. The state of watercourse buffers along such tributaries ought to be assessed by the same crew at the same time.
In 2014 the work done with culverts found 4 that were partial barriers and 21 that were full barriers to fish passage. Of these, 2 of the partial barrier culverts (C022 and C041) have already been addressed (Figure 3-9) through the work described above. The remaining 23 should be ranked in order prioritize them (by factors such as complexity of repair (due to either technical or landowner issues), upstream habitat made accessible, etc.). Then starting with those where action is most practical & beneficial they should modified as needed to make them no longer barriers to fish passage.
A second step is undertaking closer interaction with the Pollett River Watershed Project in order to facilitate contact with stakeholder groups, and build upon the work that the PRWP has already done, and the existing networks of landowners they have established within the community. This will minimize duplication of effort, and perhaps provide opportunities to join in on the implementation of priorities and projects that they have already identified.
Once the worst problem sites are known, and willing landowners have been identified as partners then the third step would be to work with such individuals on bank treatments such as revegetation to improve watercourse buffers, or upgrading inadequate water crossings. Both of these activities will help to reduce the rates at which sediment and runoff are entering the river. Downstream of Gordon Falls fish passage at these crossings would also be a concern, but up stream of the falls passage should be considered less of a priority. Development of such contacts should allow access to conduct in-stream work along sites where degradation is occurring, as landowners are likely to favor projects like log wing deflectors to protect their property, and may have resources such as money, labour, or machinery to contribute.
This is also the point where more ambitious in-stream projects such as brush matting, upstream-V log weirs, and double tree deflectors are likely to become practical. Specific information about such projects would be premature, as precise needs and sites have yet to be determined. When it is time to develop and implement those projects, Melanson et al. (2006) note that interventions must be properly designed by trained individuals spending several days doing a proper layout. Structures not sited properly are unlikely to produce the desired improvements to habitat, instead becoming buried, washed out, or creating worse problems than were present prior to installation. The presence of threatened and endangered species (salmon, eels, and wood turtles) in the watershed also means that such projects must be planned and implemented with awareness of the vulnerabilities of these species. Fort Folly Habitat Recovery has developed project checklists (Appendix A) based on species biology to provide guidelines to help avoid or minimize the risk of negative impacts.