PRK Mid-term Report 2022 by Westcountry Rivers Trust

PLYMOUTH RIVER KEEPERS MID-TERM REPORT – JANUARY 2022

Contents Plymouth River Keepers Project Area …………………………………………………………………………………………………………. 01 PRK Reaches, Fisheries and Bankside Habitat ………………………………………………………………………………………. 02

Water Quality Monitoring …………………………………………………………………………………………………………………………………. 05 Barriers to Fish Migration / SNIFFER Surveys …………………………………………………………………………………………. 14 Electrofishing Surveys ………………………………………………………................................................................................................ 23 Combined Overall Water Quality, Habitat, Obstructions and Electrofishing Results ……….. 28 Non-Native Invasive Plant Species (NNIS) ………………………….................................................................................. 32 Westcountry Citizen Science Investigations (CSI) ………..................................................................................... 34 Farm Advice and Interventions ……………………………........................................................................................................ 36 Community Engagement …………………………….................................................................................................................... 37 Preventing Plastic Pollution ……………………………............................................................................................................... 39 Plymouth River Keepers in the Community ………………….................................................................................... 40

Flood Risk Impact – NFM Prioritisation Exercise …………………........................................................................... 41 This report has been put together by Westcountry Rivers Trust as part of the Plymouth Rivers Keepers project. Published January 2022.

Plymouth River Keepers Mid-Term Report This report provides an overview of the work done to date (December 2021) by the Plymouth River Keepers project, which runs from 2020 – 2023. Included in this report are the surveys undertaken with initial results and data analysis. Westcountry Rivers Trust will continue to build this evidence base throughout the project and will use it to make decisions for proposed works within the catchment, and to monitor the effectiveness of interventions.

Plymouth River Keepers (PRK) Project Area The project area sits in the north-west of Plymouth and falls within the River Tamar management catchment, and the River Plym operational catchment. PRK PRK Project Project Boundary Area Plymouth City City Boundary Boundary Plymouth

PRK Reaches The map shows the numbered reaches in the PRK area. For the purposes of the 2017 Westcountry Rivers Trust walkover survey, the Tamerton Stream surface water catchment was divided into three broadly consistent reaches based on the geography and the nature of the reach, and the pressures exerted upon it. Reach 1 (Budshead Creek) Reach 2 Reach 3 (Tamerton Stream) Mudflats Ernesettle Creek

Reach Locations: Reach 1 – Berwick Avenue, Crownhill to Budshead Creek. Reach 2 – Crownhill Fort / Southway (Goodwin Park) to Tamerton Foliot. Reach 3 – Belliver / Haxter Wood / Porsham to Tamerton Foliot. Mudflats - Tamerton Foliot to Budshead Creek. Ernesettle Creek – Tamerton Lake to land adjacent to Redhill Close.

Reference source: Tamerton Stream and Budshead Creek Walkover Survey, Westcountry Rivers Trust (March 2017)

2017 WALKOVER SURVEY Fisheries Habitat A walkover survey was undertaken in 2017 by the Fisheries Team and the findings will help to inform the project work. This map shows where the various types of fisheries habitats are found within the project area. Reach 1 – Fry habitat was the most common habitat in Reach 1, broken in places by chutes and glides with a small amount of parr habitat near the normal tidal limit (NTL), providing sanctuary for territorial salmonids.

Culvert Bedrock Chute Fry Glide Modified Channel Parr Pool Silted Spawning Spawning

Reach 2 – The fisheries habitat in Reach 2 was more diverse than in Reach 1, alternating parr and fry habitat in many places. However, the habitat was heavily shaded which may negatively impact on the productivity of the Reach. Reach 3 – The fisheries habitat in the upper section of Reach 3 was fairly uniform fry habitat. In contrast, the lower section offers a combination of fry, parr, glides and pools. The habitat in this Reach was also heavily shaded. Mudflats - The habitat below the NTL was typical of a muddy estuary, with mudflats, glides from the NTL downwards and no overshading due to the extensive channel width.

Reference source: Tamerton Stream and Budshead Creek Walkover Survey, Westcountry Rivers Trust (March 2017)

2017 WALKOVER SURVEY Bankside Habitat A walkover survey was undertaken in 2017 by the Fisheries Team and the findings will help to inform the project work. This map shows where the various types of bankside habitats are found within the project area. Culvert Bank Erosion Bankside Fencing Revetment Shaded Tunnelled Vegetation (abandoned coppice) Tunnelled Vegetation (standards)

Rivers and streams need an adequate supply of sunlight to support primary production and their complex food web. Heavy shading and tunnelling can therefore impact the in-stream biodiversity. Our 2017 survey found that all of the reaches are over shaded and would benefit from targeted coppicing and the results of this survey will help us to inform habitat management works.

Reference source: Tamerton Stream and Budshead Creek Walkover Survey, Westcountry Rivers Trust (March 2017)

WATER QUALITY MONITORING Monthly Spot Sampling Surveys • Westcountry Rivers Trust Water Monitoring Team carried out monthly spot sampling surveys for 12 months (November 2020 to October 2021) to establish baseline water quality data.

• The 11 sampling sites were carefully chosen to monitor the main rivers and their tributaries. • Agricultural, waste-water and residential influences have been captured. • Water quality monitoring measured:

• Temperature • Electrical conductivity • Turbidity • Suspended sediment

• Colour • Phosphates • Dissolved oxygen saturation • Dissolved oxygen concentration • Colour dissolved organic matter (CDOM) • Optical brightening agents (OBA) • A summary of the water quality monitoring results can be found on the following pages.

• Full water monitoring results can be found in ‘Water Quality Monitoring Scorecard: November 2020 – October 2021’. •

Actions: (1) Further monitoring may be used to provide quantifiable evidence of improvements in water quality related to proposed interventions and improvements, e.g., farm interventions (see page 37 for details).

Reference source: Plymouth River Keepers Water Quality Monitoring Scorecard (November 2020 – October 2021), Westcountry Rivers Trust (November 2021)

WATER QUALITY MONITORING Individual Parameter Scores and Overall Water Quality Scores The table below shows how the overall scores for the subcatchments were calculated. Overall water quality was calculated using the average of the scores given for each basic water quality indicator; conductivity, phosphate, colour, sediment and C-DOM. Because CDOM and OBA tend to score the same, OBA was not included so as not to bias the overall score towards the fluorescence. Overall Water Quality Score (November 2020 - October 2021) Higher water quality Lower water quality

The Tamerton Stream at Porsham Lane (Site 7) received the lowest overall water quality score, with Budshead Stream (Site 2), Ernesettle Stream (Site 5) and the Tamerton Stream at the Seven Stars Pub (Site 6) also receiving low overall scores.

Reference source: Plymouth River Keepers Water Quality Monitoring Scorecard (November 2020 – October 2021), Westcountry Rivers Trust (November 2021)

WATER QUALITY MONITORING Individual Parameter Scores The maps show the individual parameter scores for each of the subcatchments. The overall water quality scores for each subcatchment can be found on the next page. Conductivity

Turbidity

Colour

Phosphate

CDOM

The darker shades in the maps indicate lower water quality and the lighter shades indicate higher water quality. Where no colour is indicated, no data was collected for these areas.

Reference source: Plymouth River Keepers Water Quality Monitoring Scorecard (November 2020 – October 2021), Westcountry Rivers Trust (November 2021)

WATER QUALITY MONITORING Overall Water Quality Score The map shows the overall water quality scores for each subcatchment.

Tamerton Stream Catchment ! (

WRT Sample Sites

! (

AT200 Data Logger & Timelapse Camera

Overall Water Quality Score (November 2020 - October 2021) Higher water quality Lower water quality

The Watershed tool in ArcMap GIS was used to delineate the subcatchments that represented each sampling site and a colour scale was used to represent the overall water quality score of each subcatchment.

Reference source: Plymouth River Keepers Water Quality Monitoring Scorecard (November 2020 – October 2021), Westcountry Rivers Trust (November 2021)

WATER QUALITY MONITORING Spot Sampling Conclusions and Observations • Spot sampling has shown high levels of phosphate at all sites, particularly during low water levels during the summer. • Evidence of ‘grey water’ and sewage was frequently observed. High OBA levels indicate drainage misconnections, e.g., laundry detergents. • Oxygen levels were noted to be satisfactory, with the exception of the sampling undertaken in September 2021 on the Budshead Stream, when the oxygen level was recorded as low. • Ammonia was detected on one sampling visit in September 2021. Levels were recorded at 0.5 ppm at Site 6 (Tamerton Foliot, Seven Stars pub) and 3 ppm on the Budshead Stream. The level of 3 ppm is considered to be very high, but the level of 0.5 ppm is still considered sufficient to show human input. • The low oxygen level and the presence of ammonia recorded on the September sampling visit correlated to a known pollution incident. • Low levels of turbidity and colour were recorded, with the exception of the sampling undertaken in September 2021 where high turbidity and sediment values were recorded at Site 6 (Tamerton Foliot, Seven Stars pub). This was not considered to be related to the pollution incident referred to above. • Throughout the catchment there are issues with drainage misconnections and surface water outfalls, as evidenced by the smell, visual observations and water quality results. • Litter and flytipping is also considered to be having a negative impact on the catchment. Litter was observed at 8 of the 11 sampling sites and observed 92 times during the 12-month sampling period. • Actions: (1) It is recommended that any proposed improvement works are focussed on the streams with the lowest water quality scores identified during the baseline monitoring.

Reference source: Plymouth River Keepers Water Quality Monitoring Scorecard (November 2020 – October 2021), Westcountry Rivers Trust (November 2021)

WATER QUALITY MONITORING Water Monitoring - Static Data Logger & Timelapse Camera • A Brinno trail camera was installed in the catchment in February 2020, pointing in an upstream direction. The camera was set to take a photograph every 15 minutes to provide visual data of the stream, in addition to having a motion sensor to capture wildlife. The camera was only able to take photographs during daylight hours. • The Brinno trail camera photographs have shown a rise in turbidity with rainfall events (see page 11 for an example). No unusual wildlife has been captured; motion sensor photographs include a cat, a pigeon and a grey squirrel. • A Spypoint trail camera replaced the Brinno trail camera in December 2020. The replacement was made due to the Spypoint camera having a better ability to take photographs in the dark. The camera is set to take a photograph every 15 minutes. The first data from the camera will be collected in January 2022. • An Aqua TROLL 200 sonde (data logger) was installed in the catchment in July 2020, upstream from the trail camera. The sonde captures data on water depth, temperature and electrical conductivity. The sonde is connected to a Mace telemetry unit, which sends this data to the HydroVu website every 15 minutes. • The sonde is set to trigger an alarm if the conductivity exceeds 310 µS/cm, which may indicate a pollution incident has occurred. This figure is based on analysis of conductivity data which shows a median value of 292 µS/cm. As more data is received from the sonde this trigger level may be adjusted.

• The sonde alarm has been triggered on three occasions to date, although on the first two occasions the conductivity was only marginally over the trigger level so it is not yet clear if this was significant. On each occasion a CSI volunteer or local River Keeper has been contacted and has either undertaken a CSI survey or made a visual assessment of the stream on behalf of Westcountry Rivers Trust. • Actions: (1) Aqua TROLL 200 data to be transmitted via telemetry to an online platform that will be available to the community to view. This data is currently only available for WRT staff to view. This work is in progress.

Reference source: Plymouth River Keepers Water Quality Monitoring Scorecard (November 2020 – October 2021), Westcountry Rivers Trust (November 2021)

WATER QUALITY MONITORING Water Monitoring - Static Data Logger & Timelapse Camera Data The graph to the left shows the spike in conductivity which occurred during the night on 30th November 2021. The conductivity level reached 611µ/cm.

A visual survey was carried out by a local River Keeper the following morning and no visible signs of pollution were evident. The cause of the conductivity spike is unknown. Unfortunately as the spike occurred during hours of darkness, the Brinno trail camera was unable to capture photographs of this event. The trail camera has since been replaced with a model that will be able to capture photographs in hours of darkness.

The images above were captured by the Brinno trail camera on 18th March 2021 (and therefore do not related to the graph to the left). The top photo shows the usual state of the Tamerton Stream, whilst the bottom photo was captured after rain and shows a rise in turbidity.

WATER QUALITY MONITORING Invertebrate Sampling – Riverfly Method Invertebrate sampling was carried out using the Riverfly Partnerships’ ARMI (Anglers’ Riverfly Monitoring Initiative) methodology. This method comprises a 3-minute kick sample followed by a 1-minute hand search. This method was chosen so that it can be replicated by volunteers. ( !

Riverfly Monitoring Point

Three Riverfly monitoring points have been identified: BDS-01(U/S), CNS-01 and TMS-02. Two samples were taken at each of the three Riverfly sites during 2021. This was to establish a baseline to aid in assigning a trigger level and to establish these sites for volunteer monitoring. The trigger level is the baseline score given to a waterbody. After collecting a sample, if the score (determined from numbers of species collected during sampling) is above the trigger level then the stream health is satisfactory, and no action is needed. If the score is below the trigger level the site must be resampled and, if still below the trigger level, the local Riverfly Coordinator and the Environment Agency should be informed.

Reference source: Plymouth River Keepers Water Quality Monitoring Scorecard (November 2020 – October 2021), Westcountry Rivers Trust (November 2021)

WATER QUALITY MONITORING Invertebrate Sampling – Riverfly Preliminary Results • After consultation with the Environment Agency ecology lead, it was determined that sites CNS-01 and TMS-02 should both have a trigger level of 7 and site BDS-01 (U/S) should have a trigger level of 4.

• At site BDS-01, an initial kick sample on 24th April 2021 was taken downstream (D/S) of a constantly discharging pipe. However, the score was extremely low (see BDS-01 in the table below), suspected to be due to the pipe discharge. It was therefore decided that all future samples should be taken upstream (U/S) of the discharging pipe to discount its effects on the invertebrate population. The score of 4 for Site BDS-01 (U/S) is still very low, indicating that the stream is receiving pollutants which decrease the diversity of the invertebrate populations. It was also noted that there were leeches and bloodworms present in the sample which are all pollution tolerant species. • All other sites had good diversity and abundance of the eight Riverfly species (see Sites CNS-01 and TMS-02 in the tables below). Site TMS-02 in March showed the highest abundance and diversity of species of all kick samples taken. • It was not possible to undertake monthly kick-sampling surveys due to time constraints. The aim is for Riverfly to be undertaken by volunteers in the future, trained and supported by Westcountry Rivers Trust staff. • Actions: (1) Riverfly Training of WRT staff – proposed for 2022. (2) Volunteer recruitment and training. Volunteers to be supported by WRT staff to encourage commitment throughout the project and beyond. BDS-01

CNS-01

Budshead Stream below 24-Aproverhead pipe 21 Score 26-Jul-21 Score

Cann Stream @ Old Weir 23-Jun-21 Score

Cased Caddis

Caseless Caddis True Mayfly (Epherimedae)

Flat Bodied Mayfly

Olive Mayfly

Blue-winged Olive Mayfly

Stonefly

TMS-02

24-Sept21 Score

1 1

25 40

2 2

25 30

Tamerton Stream @ Seven Stars Pub

16-Mar-21 Score

24-Aug21 Score

Cased Caddis

Caseless Caddis True Mayfly (Epherimedae)

Flat Bodied Mayfly

1 20

Olive Mayfly

Blue-winged Olive Mayfly

Stonefly

Gammarus

Total

100

Total

148

Reference source: Plymouth River Keepers Water Quality Monitoring Scorecard (November 2020 – October 2021), Westcountry Rivers Trust (November 2021)

Barriers to Fish Migration / SNIFFER Surveys • The detailed approach of using the SNIFFER protocol allows us to not only judge individual barriers but make an assessment of catchment scale priorities for fish passage solutions. SNIFFER surveys of the fish migration barriers in our project area will determine their impact on the catchment. A prioritization exercise will ascertain which barrier works would provide the most benefit. An explanation of the SNIFFER protocol can be found on the next page. • Fifteen migration barriers were identified as requiring surveys and categorised into separate reaches (Reaches 1 and 2). All obstacles were surveyed using both SNIFFER and Eel Barrier Field Guide protocols in April 2021 during low flow river levels. • The findings of the survey support that all 15 barriers are having an impact on migration of one or more species. It was highlighted that upstream migration is the most impacted, with many structures being a complete barrier to fish migration. It was found that culvert type obstacles were the worst scoring barriers, with many acting as barriers to upstream migrants. • The SNIFFER surveys highlighted characteristics of shallow depths and moderate to high velocities were having the biggest impact.

• None of the structures surveyed comply with the current The Eels (England and Wales) Regulations 2009 and it is apparent that mitigation is needed at all sites to help improve passage of these critically endangered species. Where possible removal has been recommended as the best possible option for all species. However, in some cases this is not possible due to the complexity of each structure e.g., where culverts run under large areas of carriageway. In these cases, technical fish passes have been recommended for partial mitigation. It is hoped by addressing migration issues at these barriers, large areas of habitat can be made accessible to all species. • Full results can be found in ‘Plymouth River Keepers – Fish Passability Assessment’ (December 2021). • Actions:

(1) Additional walkover to be undertaken in early 2022 to identify any additional barriers not identified in 2017. (2) High-flow SNIFFER surveys to be undertaken in early 2022. (3) Prioritisation exercise for removal / easement of fish migration barriers. (4) Removal / easement of fish migration barriers. Reference source: Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021)

Barriers to Fish Migration / SNIFFER Surveys The barriers to fish migration identified so far are shown on the map. Further surveys may identify additional barriers.

Obstruction - Survey Type

! P P ! P ! P !

SNIFFER survey not proposed SNIFFER survey proposed, no access SNIFFER survey proposed, not yet undertaken SNIFFER survey undertaken 2021

The SNIFFER protocol is a technique developed by the Scottish and Northern Irish Forum For Environmental Research (SNIFFER). The surveys look in-depth at barriers (such as weirs) to give expert judgement of its “passability” in terms of different migratory fish species. During the process many measurements are taken such as head height, flows, depth and transect across the barrier itself. All this data is inputted into the protocol using a dedicated guidance manual to give a final assessment.

Reference source: Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021)

Barriers to Fish Migration / SNIFFER Surveys The barriers to fish migration which were subject to SNIFFER surveys in April 2021 are shown on the map.

P SNIFFER survey undertaken (2021) !

The IDs on the map, e.g. 1E, have been given to the obstructions to identify them. Further information on these obstructions and the full results of the SNIFFER surveys can be found in the WRT ‘Fish Passability Assessment Report’ (December 2021).

Reference source: Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021)

SNIFFER Survey 2021 – Results (Reach 1 – Adult Trout) The barriers to fish migration which were subject to SNIFFER surveys in April 2021 are shown on the map.

Passability Score for Adult Trout (US / DS)

! < < ! < ! < ! < ! < ! < ! < !

No barrier / No barrier Partial barrier (low) / No barrier Partial barrier (low) / Partial barrier (low) Partial barrier (high) / No barrier Partial barrier (high) / Partial barrier (low) Total barrier / No barrier Total barrier / Partial barrier (high) Total barrier / Total barrier

The map shows the SNIFFER protocol passability score for adult Trout: Upstream

< !

/ Downstream

< !

Partial barrier (low) relates to low impact barrier. Partial barrier (high) relates to high impact barrier.

Reference source: Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021)

SNIFFER Survey 2021 – Results (Reach 2 – Adult Trout) The barriers to fish migration which were subject to SNIFFER surveys in April 2021 are shown on the map.

Passability Score for Adult Trout (US / DS)

! < < ! < ! < ! < ! < ! < ! < !

The map shows the SNIFFER protocol passability score for adult Trout: Upstream

Reference source: Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021)

< !

/ Downstream

< !

SNIFFER Survey 2021 – Results (Reach 1 – Juvenile Eel / Adult Eel) The barriers to fish migration which were subject to SNIFFER surveys in April 2021 are shown on the map.

Passability Score for Adult Eels / Juvenile Eels

! < < ! < ! < ! < ! < ! < !

No barrier / No barrier No barrier / Total barrier Partial barrier (low) / Partial barrier (low) Partial barrier (high) / No barrier Total barrier / No barrier Total barrier / Partial barrier (low) Total barrier / Total barrier

The map shows the SNIFFER protocol passability score: Adult Eel Upstream

Reference source: Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021)

< !

Juvenile Eel Downstream

< !

SNIFFER Survey 2021 – Results (Reach 2 – Juvenile Eel / Adult Eel) The barriers to fish migration which were subject to SNIFFER surveys in April 2021 are shown on the map.

Passability Score for Adult Eels / Juvenile Eels

! < < ! < ! < ! < ! < ! < !

The map shows the SNIFFER protocol passability score: Adult Eel Upstream

Reference source: Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021)

< !

Juvenile Eel Downstream

< !

ZSL Eel Assessment 2021 – Results (Reach 1 – Eel) The barriers to fish migration which were subject to SNIFFER surveys in April 2021 are shown on the map.

Eel Passability Score Range ( !

<05

Likely to be a complete obstacle to eels migrating upstream

( !

05-09 Partial impact, obstacle may impede passage

( !

10-15 Unlikely to represent a major barrier to upstream migration

After the initial SNIFFER assessment, a further assessment was carried out using the field guide for eels formulated by the Zoological Society of London (ZSL) intended to provide an eelspecific assessment methodology, hereby referred to as ZSL-Eel assessment. This data allowed the assignment of passability scores as per the scale above.

Reference source: Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021)

ZSL Eel Assessment 2021 – Results (Reach 2 – Eel) The barriers to fish migration which were subject to SNIFFER surveys in April 2021 are shown on the map.

Eel Passability Score Range ( <05 !

Likely to be a complete obstacle to eels migrating upstream

( 05-09 Partial impact, obstacle may impede ! passage

< !

05-09/ Partial impact, obstacle may impede passage/ 10-15 Unlikely to represent a major barrier to upstream migration

( 10-15 !

Unlikely to represent a major barrier to upstream migration

The two transversal sections of 2D were assessed independently and each had a different eel passability score, as indicated by the two-tone symbol. For all other obstacles where more than one transversal section was present, the eel passability score fell within the same range for all sections.

Reference source: Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021)

Electrofishing Surveys • WRT carried out timed semi-quantitative, fry index electrofishing surveys at 11 sites in the PRK project area in September 2021 (see pages 26 & 27 for EF locations and results). The surveys were the first year of a three-year monitoring effort as part of the project, undertaken prior to any works taking place, e.g., habitat improvement works or removal of fish migration barriers. • The 2021 surveys demonstrate that the small streams within the PRK project area have the potential to support excellent salmonid spawning and the importance of these small streams to salmonids.

• Salmon were absent from all sites. The only species that were present at some sites were brown trout and European eel. There were two ‘A’ classification sites in 2021, along with two ‘B’ classification sites. Trout fry were absent from seven of the 11 sites. It appears that when trout were present, they were present in relatively good numbers. • Reach 1 was the worst performing of the small streams, with only eel present in the lowest of sites and no trout caught throughout its entire length. There are two significant barriers in the form of pipe culverts in the lower section of the stream and directly above the lowest site. The data would suggest that these are impacting passage of both trout and eel. This is further strengthened by data already acquired by the PRK project SNIFFER surveys conducted on these structures, which have indicated that they likely present a complete obstacle to all fish species and all life stages. • Reach 2 performed the best; with trout and eel being recorded at three of the five sites surveyed with the highest number of fish being present at the lowest sites and slightly decreasing the further upstream the sites were located. However, there were some good sections of habitat present along this reach with dappled light, tree roots and refuge established along the banks, with deeper pool sections present to hold larger numbers of fish. Again, a pipe culvert was present on the more northerly section of the stream as it forked off from the main stream and this is where all fish species were found to be absent. Previous structure assessments support that this pipe culvert is a complete obstacle to all fish species and life stages and would support the lack of fish present in this section. Further man-made structures are present along this section further increasing the likelihood of impediment to fish passage. • Reach 3 Unfortunately, due to landowner permission not being obtained, only one site was surveyed at lower end of Reach 3, but this site did produce good numbers of trout and eel. Habitat upstream also appears to be of good quality and would suggest the possibility of trout also being present in this section, but further investigation into other obstacles that may be present is needed. • Apart from the structures limiting the free passage of fish to access better quality habitat and spawning areas, some of the areas of these small streams really lacked quality habitat to support the basic needs of many fish species. Long areas of these streams were completely tunnelled and shaded and suffered with high levels of siltation in places. Furthermore, water quality has been an issue in the area due to pollution incidents and run off. Reference source: Plymouth River Keepers Electrofishing Fry Index Survey, Westcountry Rivers Trust (October 2021)

Electrofishing Surveys – Recommendations • The strategy for restoration and conservation of sites recommended broadly follows the Defend/Repair/Attack concept (developed by Ronald Campbell, Tweed Foundation). It can be applied on a subcatchment level with recommended fisheries management actions suggested to either improve or maintain salmonid habitat and numbers. • The aim would be to move all sites from their current position to the Defend category, or to ensure they remain in this status if fish stocks are already good. Category

Status

Action

Defend

These areas have good fish stocks and habitat. These areas need safeguarding actions to ensure no decline occurs.

Maintain bag limits Habitat safeguarding

Repair

These areas have moderate fish stocks, and fish habitat in a moderate condition. These areas need assisted habitat recovery to move them into the Defend category.

Catch and release Assisted habitat recovery

Attack

These areas have poor fish stocks, and the habitat is significantly degraded. These areas need drastic intervention such as habitat reengineering in order to improve their status.

Stock action Habitat re-engineering

Subcatchment

Average Fry Index Class & Conservation Strategy Salmon

Trout

Reach 1

Absent Attack

Reach 2

Absent Attack

Reach 3

Absent Attack

Good Repair

Reference source: Plymouth River Keepers Electrofishing Fry Index Survey, Westcountry Rivers Trust (October 2021)

The table to the right shows the Plymouth River Keepers subcatchment classification and Defend/Repair/Attack strategy. Despite excellent trout fry populations in some areas, it is important that defence strategies are put in place to maintain good recruitment and to restore numbers elsewhere in the project area. In all areas, salmon are absent, then the attack strategy and appropriate actions should be implemented where funding allows. Therefore, management strategies need to be considered for each species, hence a conservation strategy for both salmon and trout.

Electrofishing Surveys – Recommendations • To begin to restore and/or maintain fry habitat in the PRK project area, WRT recommend the following works: • Coppicing: Targeted selective coppicing of woodland and abandoned riparian coppice adjacent to juvenile habitat riffles should be undertaken. This will increase primary productivity and food source for juvenile fish. Shade should be maintained on deeper pools and runs for water temperature and adult fish habitat cover. • Erosion Control: Fencing and effective marginal habitat management will reduce erosion. However, where specific areas of high pressure and vulnerability are identified, erosion protection measures such as woody debris installation, environmentally sensitive revetments, and strategic tree planting would be advantageous. • Fish Passage Assessment: Assessment of potential fish migration barriers using the Coarse Resolution Rapid Assessment technique developed by the Scottish and Northern Irish Forum For Environmental Research (SNIFFER). A standardised survey technique to assess porosity of in-channel structures. • In-Channel Habitat Restoration: Installation and construction of habitat enhancing features, including woody debris introduction, flow manipulation with groins and kickers, bank reprofiling for marginal zonation, strategic tree planting, gravel introduction and riffle creation, and historic channel restoration. Advanced management usually applied post success of other recommended actions. • Interpretation: Sensitive spawning sites can be exposed to disturbance at key times of year. Interpretation can be used to inform of salmonid presence and advise on in-river site avoidance. • Increase monitoring effort: Some sites are very difficult to access and therefore are not surveyed. By increasing survey effort, more information on whole catchment performance can be achieved and allow for increase appropriate action. Increased surveys could include EF surveys red counts, invertebrate monitoring e.g., Riverfly and Westcountry CSI (citizen science program) run by WRT.

Sub-catchment Reach 1 Reach 2 Reach 3

Fencing

Coppicing

✓ ✓

Erosion Control ✓ ✓

Fish Passage Assessment ✓ ✓ ✓

Action In-channel Modify Flow Habitat Regime Restoration ✓ ✓ ✓

Reference source: Plymouth River Keepers Electrofishing Fry Index Survey, Westcountry Rivers Trust (October 2021)

Walkover Surveys

✓

Interpretation

✓ ✓ ✓

Increase Monitoring Effort

✓

Electrofishing Surveys – Trout (semi-quantitative) The map below shows the results of the 2021 electrofishing surveys for trout fry.

EF Results 2021 - Trout Fry

# * # * # * # * # *

A - Excellent B - Good C - Fair D - Poor E - Absent

The results were classified according to the methodology of Crozier and Kennedy (1994). The numbers relate to fry abundance: Density Classification A (Excellent) B (Good) C (Fair) D (Poor) E (Absent)

Semi-quant (5 min) >23 11-23 5-10 1-4 0

The numbers on the map in bold indicate the number of trout fry identified during the survey, on which the classification is based. The numbers in brackets indicate the number of trout parr identified.

Reference source: Plymouth River Keepers Electrofishing Fry Index Survey, Westcountry Rivers Trust (October 2021)

Electrofishing Surveys – European Eel (Presence / absence) The map below shows the results of presence / absence surveys for European Eel at 11 sites in September 2021.

EF Results 2021 - Eel

# * # *

Eel Absent Eel Present

What is electrofishing?

Electrofishing is one of the most accurate methods of assessing fish populations. Electrofishing uses a controlled electric current to temporarily immobilise fish or influence them to swim in a particular direction to be caught with a hand net, and thereby be counted and assessed. When carried out correctly by experienced and qualified surveyors, it is not harmful to fish and the fish are released back to the same location they were caught.

Reference source: Plymouth River Keepers Electrofishing Fry Index Survey, Westcountry Rivers Trust (October 2021)

Combined Overall Water Quality, Habitat, Obstructions and Electrofishing (Trout) Results (Reach 1 ) The map shows the fisheries and bankside habitats (2017), electrofishing results (trout fry – 2021) and the obstructions to fish migration (2017 & 2021) alongside the overall water quality score (November 2020 – October 2021). Fisheries Habitat (2017) Bedrock Chute Fry Glide Modified Channel Parr Pool Silted Spawning Spawning

Bankside Habitat (2017) Bank Erosion Bankside Fencing Revetment Shaded Tunnelled Vegetation (abandoned coppice) Tunnelled Vegetation (standards)

P !

Obstructions (identified 2017 / 2021)

EF Results 2021 - Trout Fry

# * # * # * # * # *

Overall Water Quality Score (November 2020 - October 2021) Higher water quality

A - Excellent B - Good C - Fair D - Poor E - Absent

Lower water quality Reference source: Plymouth River Keepers Water Quality Monitoring Scorecard (November 2020 – October 2021), Westcountry Rivers Trust (November 2021) / Tamerton Stream and Budshead Creek Walkover Survey, Westcountry Rivers Trust (March 2017) / Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021), Plymouth River Keepers Electrofishing Fry Index Survey, Westcountry Rivers Trust (October 2021)

Combined Overall Water Quality, Habitat, Obstructions and Electrofishing (Trout) Results (Reach 2 & 3) The map shows the fisheries and bankside habitats (2017), electrofishing results (trout fry – 2021) and the obstructions to fish migration (2017 & 2021) alongside the overall water quality score (November 2020 – October 2021). Fisheries Habitat (2017) Bedrock Chute Fry Glide Modified Channel Parr Pool Silted Spawning Spawning

Bankside Habitat (2017) Bank Erosion Bankside Fencing Revetment Shaded Tunnelled Vegetation (abandoned coppice) Tunnelled Vegetation (standards)

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Obstructions (identified 2017 / 2021)

EF Results 2021 - Trout Fry

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Overall Water Quality Score (November 2020 - October 2021) Higher water quality

A - Excellent B - Good C - Fair D - Poor E - Absent

Combined Overall Water Quality, Habitat, Obstructions and Electrofishing (Eel) Results (Reach 1 ) The map shows the fisheries and bankside habitats (2017), electrofishing results (eel – 2021) and the obstructions to fish migration (2017 & 2021) alongside the overall water quality score (November 2020 – October 2021). Fisheries Habitat (2017) Bedrock Chute Fry Glide Modified Channel Parr Pool Silted Spawning Spawning

Bankside Habitat (2017) Bank Erosion Bankside Fencing Revetment Shaded Tunnelled Vegetation (abandoned coppice) Tunnelled Vegetation (standards)

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Obstructions (identified 2017 / 2021)

EF Results 2021 - Eel

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Overall Water Quality Score (November 2020 - October 2021)

Eel Absent Eel Present

Higher water quality Lower water quality Reference source: Plymouth River Keepers Water Quality Monitoring Scorecard (November 2020 – October 2021), Westcountry Rivers Trust (November 2021) / Tamerton Stream and Budshead Creek Walkover Survey, Westcountry Rivers Trust (March 2017) / Plymouth River Keepers Fish Passability Assessment, Westcountry Rivers Trust (June 2021), Plymouth River Keepers Electrofishing Fry Index Survey, Westcountry Rivers Trust (October 2021)

Combined Overall Water Quality, Habitat, Obstructions and Electrofishing (Eel) Results (Reach 2 & 3) The map shows the fisheries and bankside habitats (2017), electrofishing results (eel – 2021) and the obstructions to fish migration (2017 & 2021) alongside the overall water quality score (November 2020 – October 2021). Fisheries Habitat (2017) Bedrock Chute Fry Glide Modified Channel Parr Pool Silted Spawning Spawning

Bankside Habitat (2017) Bank Erosion Bankside Fencing Revetment Shaded Tunnelled Vegetation (abandoned coppice) Tunnelled Vegetation (standards)

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Obstructions (identified 2017 / 2021)

EF Results 2021 - Eel

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Overall Water Quality Score (November 2020 - October 2021)

Eel Absent Eel Present

Non-native Invasive Plant Species (NNIS) • Non-native invasive plant species are present throughout the project area, associated with the riparian habitats and surrounding woodlands. • Wildlife & Countryside Act 1981 – Species in the project area listed on the WACA (Schedule 9) include Himalayan Balsam, Japanese Knotweed, Giant Hogweed and Rhododendron. This means that it is against UK law to cause or allow the plant to spread in the wild. • NNIS often out-compete native plant species for nutrients, light and space. Some species, e.g., Himalayan Balsam, also outcompete native plants for pollinators which can lead to reduced pollination of native plants, and can destabilise banks due to their shallow root systems. • NNIS removal took place in 2021 of Himalayan Balsam in Whitleigh Wood and Water Fern (Azolla filiculoides) in Budshead Pond, with community involvement. • The project area would benefit from further removal of NNIS and this could be done as community volunteer events, in addition to working with the landowners, including Plymouth City Council and Woodland Trust.

• ACTIONS: (1) Arrange 2022 NNIS removal with River Operations Team and as community volunteer events. Whitleigh Wood Himalayan Balsam removal volunteer event scheduled for June 2022 with Woodland Trust, more events to follow. (2) Further NNIS surveys to be undertaken in the PRK area in summer 2022 (River Operations Team). Fixed Point Photography Post showing the removal of Water Fern on Budshead Pond, using weevils as biological control. The photo on the left shows the pond on the day of weevil release on 03/08/2021, the photo on the rght shows the pond on 01/12/2021.

Himalayan Balsam removed from Whitleigh Wood, June 2021

Non-native Invasive Plant Species (NNIS) The map shows the known locations of invasive non-native plant species in the project area.

Non-native invasive plant species surveys were carried out in summer 2021 of Whitleigh Wood and Woodland Wood. Further surveys and removal of non-native species will be carried out throughout the project. Walkover Survey 2017 ! ( Giant Hogweed ! ( Japanese Knotweed NNIS Survey 2021

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Bamboo

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Himalayan Balsam

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Himalayan Balsam - removed June 2021

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Laurel

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Rhododendron

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Water Fern - removed Aug-Oct 2021

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Winter Heliotrope

Westcountry Citizen Science Investigations (CSI) • Westcountry CSI is a volunteer program which aims to educate and engage people with the water environment, to produce data that can be used to target work and identify degrading water bodies, to spot pollution events so that they can be dealt with as quickly as possible and to create a network of catchment communities that are invested in their local environment. • The aim is for Westcountry CSI sampling undertaken by volunteers to take the place of the monthly sampling done by the WRT Water Monitoring Team, which ended in October 2021 following 12 months of surveys.

• The sampling point in Southway Valley LNR has been added to include this neighbourhood for community engagement purposes and has not therefore had any previous water monitoring by WRT. • As of December 2021, four active volunteers were sampling regularly in the project area. • Westcountry CSI volunteers have participated in extra water quality related surveys at very short notice when required following suspected pollution incidents, for example a fish kill on Budshead Pond (which was attributed to low O2 levels) and high conductivity alerts from the sonde on the Tamerton Stream. This has provided invaluable data for the project. • Previous volunteers who started sampling and received kit, or who signed up but did not begin surveying, were contacted in summer/autumn 2021 to see if they wished to continue or were in need of any additional support. • A Westcountry CSI volunteer training event was held in November 2021 in Tamerton Foliot. The aim was to increase the uptake of the scheme but was also open to existing volunteers to provide ongoing support. Eight people attended the training, with four signing up to be a CSI volunteer. None of the attendees signed up to volunteer in the project area.

• ACTIONS: (1) Further training sessions and recruitment drive to be planned for early 2022. (2) Volunteer CSI Co-Ordinator to be recruited from existing volunteers in project area to provide support to other volunteers, distribute water monitoring kit etc. (3) Volunteers to be supported by WRT staff to encourage commitment throughout the project and beyond.

Westcountry Citizen Science Investigations (CSI) The map shows the Westcountry CSI sample points across the catchment, including which sample points are actively being sampled by volunteers (information correct in December 2021). CSI Sample Points Active Volunteer? ! (

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Yes

In December 2021, four volunteers were active in the catchment, regularly sampling six CSI sample points between them.

Farm Advice and Interventions • WRT Farm Advisors began working with farmers and landowners to the north of the Plymouth River Keepers project area in 2020.

• For eligible farms in the area, Farm Advisors will undertake a full farm survey and provide a farm plan with an aim to deliver land management advice and on-farm measures to minimise pollutant loss from farms while maximising efficiency & enhancing ecological health.

Farm visits and plans / interventions to benefit the environment and water quality: • • • • •

Reducing pollution e.g. from run-off. Management of water courses. Natural flood management (NFM) options. Farm waste management, including plastics with Preventing Plastic Pollution (PPP) project. Soil health.

Community Engagement - Online Events • The Plymouth River Keepers team have hosted a series of online events, including a ‘Roundtable’ event in September 2020, in partnership with the Bioregional Learning Centre, a ‘River Dip’ in September 2020 (a bitesize tour of the project), and a Festive Event in December 2020. These events were open to members of the local community, local organisations and landowners (e.g., Plymouth City Council and Woodland Trust) to meet the team and allow them to find out more about the project. These online events were a valuable way to connect with the community during Covid-19 restrictions. • Between February and June 2021, the Plymouth River Keepers project collaborated with the Conscious Sisters (a Plymouth-based CIC) to run a series of online sessions with the aim to connect people to place, with the River Keepers Clan being centred around Budshead Creek. Sessions included history, foraging, ecology and storytelling. One member of the group has become a committed Westcountry CSI volunteer, whilst other members have remained connected to the project and have taken on other River Keeper roles, for example reporting pollution incidents, sharing project information with their communities and attending events such as litter picks. • ACTIONS:

(1) Further online events to be organised, including a series of science webinars scheduled to take place in early 2022. As part of ClanKind, the group created a banner. Each group member created two silk paintings, depicting animals or landscape scenes from the area on which the Clan was based - Budshead Creek. The banner will be used at future Plymouth River Keepers events.

Community Engagement – Face-to-Face Events • In 2021 the project has engaged approximately 375 people in the local community. Events included: • Three pop-up events in local green spaces, to provide an informal drop-in for the local community to meet the team and find out more about the project – Ernesettle Green, Southway Valley and Tamerton Foliot Carnival. • Himalayan Balsam removal event (alongside a PPP litter pick) in Whitleigh Wood. • NSPCC Together for Children event, to nurture children's love of nature in a safe and supportive environment. • An evening talk to Soroptimist International Plymouth and District group. • A Christmas stall at Ernesettle Christmas Extravaganza and Christmas lights switch-on. • ACTIONS: (1) Further community engagement events to be organised in 2022. (2) Events currently scheduled for 2022 include a stall at the Tamerton Foliot Carnival (May 2022) and a Himalayan Balsam removal and litter picking event in Whitleigh Woods (June 2022).

NSPCC Together for Children event, August 2021

Southway Valley Pop-up Event, invertebrate sampling kit, August 2021.

Ernesettle Green Pop-up Event, July 2021.

Preventing Plastic Pollution • Plymouth River Keepers are working in partnership with Preventing Plastic Pollution (PPP) in the project area. • In 2021, six litter picks and litter surveys were held in the project area: • Whitleigh Wood (two events in this location), Tamerton Foliot (Riverside Walk), Woodland Wood, Southway Valley and Budshead Pond/Budshead Wood. • Over the six litter picks 25 volunteers took part, with a combined total of 56 volunteer hours. • Over 32km2 of riparian habitat was cleared of litter and flytipping. • Approximately 151kg of litter was collected and removed from the environment, including 109kg of plastic. • ACTIONS: (1) Arrange 2022 litter picks and river clean-ups with PPP, the community and River Operations Team. To be undertaken primarily in areas proposed for fish migration barrier removal works and habitat management, to help improve the overall water and habitat quality in those areas for fish and other wildlife. Additional litter hotspots also to be targeted.

Litter removed from Whitleigh Wood, June 2021

Budshead Pond and Woodland litter pick, October 2021.

Tamerton Foliot litter pick, July 2021.

Plymouth River Keepers in the Community • Members of the local community have taken on a variety of River Keeper roles, including becoming Westcountry CSI volunteers, attending events such as litter picks and pop-up events, sharing project information and events with their local groups and communities, or taking photographs from our Fixed Point Photography posts. An important River Keeper role is that of reporting pollution incidents and we have members of the community who regularly report incidents to the Environment Agency, in addition to keeping WRT informed of any incidents. Pollution incidents • Since the start of the project, WRT have received 27 reports of suspected pollution in the project area. These include:

• Four incidents involving dead fish and/or crabs (one incident on Budshead Pond was later attributed to low O2 levels). • Six incidents related to sewage and sewage related litter being released from manhole covers. • One incident relating to SWW treatment works. • Two incidents relating to local factories. • Two incidents relating to works on the highway and/or culverts. • Six suspected pollution incidents on Tamerton Lake. In two of these Tamerton Lake incidents sanitary items and sewage related litter was observed, and in one incident a large number of dead fish and crabs were observed. It has been reported to us that these Tamerton Lake incidents often occur on the incoming tide. The Environment Agency have attributed a proportion of these incidents to algal bloom. • Waterways have been affected by these incidents, in addition to public footpaths and a community orchard. • These incidents have either been reported to the Environment Agency by the community member or by the PRK project team. • ACTIONS: (1) Continue to encourage and support local community members to be River Keepers, to report suspected pollution incidents to the Environment Agency, and to keep in regular contact. (2) WRT to keep a log of all suspected pollution incidents reported to them, to build up a picture of issues in the project area. 40

Flood Risk Impact – NFM Prioritisation Exercise This map shows ‘subcatchments’ in the wider Tamerton Stream catchment. When targeting measures in a landscape, it is often useful to summarise risk by distinct spatial units, so that patterns for combined impacts can be visualised more clearly. For floodrisk mitigation, a useful spatial unit for this exercise is the hydrological boundary of rivers, streams or other surface water flow pathways. Tamerton Stream Catchment Subcatchments

The Watershed tool in ArcMap GIS was used to calculate the hydrological catchment of the Tamerton Stream. For the purposes of the flood risk impact exercise, the Tamerton Stream catchment was divided into smaller ‘subcatchments’ using a more refined watershed dataset created by the University of Exeter (via the SWEEP project). Some of these catchments have been merged or split to create polygons of a similar size.

The potential flood risk (of both surface water flooding and fluvial flooding) was calculated for each of the ‘subcatchments’ for 1 in 100 year rainfall events. This information will be used to prioritise areas for any potential NFM (Natural Flood Management) interventions.

Surface Water Flooding – Infrastructure at Potential Risk These maps show the extent of surface water flooding for a 1 in 100 year rainfall event, highlighting buildings (over 40m 2), roads and agricultural land at potential risk. BUILDINGS AT RISK FLOOD ZONES (1 in 100 year event)

Buildings potentially at risk of surface water flooding

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Maximum extent of surface water flooding

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Tamerton Stream Catchment

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Surface water

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ROADS AT RISK

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Roads potentially at risk of surface water flooding

AGRICULTURAL LAND AT RISK Agricultural Land

Agricultural land potentially at risk of surface water flooding

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Surface Water Flooding – Summarising Flood Risk Impact The three smaller maps on the right summarise the potential flood risk impact for each of the ‘subcatchments’ within the Tamerton Stream catchment. Each ‘subcatchment’ is given a high-low score for buildings (over 40m2), roads and agricultural land. The map on the left combines these scores to give an overview of combined flood risk impacts. FLOOD RISK IMPACT SUMMARY By surface water ‘subcatchment’

BUILDINGS AT RISK

Tamerton Stream Catchment

ROADS AT RISK

AGRICULTURAL LAND AT RISK

Combined Potential Flood Risk Impact Score

Potential Flood Risk Impact Score

Higher

Lower

Fluvial Flooding – Infrastructure at Potential Risk These maps show the extent of fluvial flooding for a 1 in 100 year rainfall event, highlighting buildings (over 40m 2), roads and agricultural land at potential risk. BUILDINGS AT RISK FLOOD ZONES (1 in 100 year event)

Buildings potentially at risk of fluvial flooding

Maximum extent of fluvial flooding Tamerton Stream Catchment

Surface water

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ROADS AT RISK Roads potentially at risk of fluvial flooding

AGRICULTURAL LAND AT RISK Agricultural Land

Agricultural land potentially at risk of fluvial flooding

Fluvial Flooding – Summarising Flood Risk Impact The three smaller maps on the right summarise the potential flood risk impact for each of the ‘subcatchments’ within the Tamerton Stream catchment. Each ‘subcatchment’ is given a high-low score for buildings (over 40m2), roads and agricultural land. The map on the left combines these scores to give an overview of combined flood risk impacts. FLOOD RISK IMPACT SUMMARY By surface water ‘subcatchment’

BUILDINGS AT RISK

Tamerton Stream Catchment

ROADS AT RISK

AGRICULTURAL LAND AT RISK

Combined Potential Flood Risk Impact Score

Potential Flood Risk Impact Score

Higher

Lower

DATASET SOURCES: Page numbers in teal show which maps/indicators the dataset was used to create.

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Environment Agency: Surface Water. © Environment Agency copyright and/or database right 2014. Included in the CaBA data package (2, 3, 4, 8, 12, 15, 16, 17, 18, 19, 20, 21, 22, 26, 27, 28, 29, 30, 31, 33, 35, 41, 42, 43, 44, 45)

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Environment Agency: SWEEP South West UK Surface Water Runoff Catchment Dataset © Environment Agency copyright and/or database right 2015. All rights reserved. Contains Ordnance Survey data © Crown copyright and database right 2019 (41, 42, 43, 44, 45)

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Environment Agency: The Environment Agency Risk of Flooding from Rivers and Sea. Contains public sector information licensed under the Open Government Licence v3.0. © Environment Agency copyright and/or database right 2018. All rights reserved. Some features of this map are based on digital spatial data from the Centre for Ecology & Hydrology, © NERC (CEH) © Crown copyright and database rights 2018 Ordnance Survey 100024198 (42, 44)

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NERC: Tamerton Stream Catchment. Contains Digital Elevation Model (DEM) from Tellus SW © NERC 2017 (7, 8, 41, 42, 43, 44, 45)

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Plymouth City Council: Plymouth Neighbourhoods. Contains public sector information licensed under the Open Government Licence v3.0 (1)