Property:Monitoring surveys and results
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2013's post-restoration electro-fishing survey recorded 705 fish representing 12 species, an increase from the 107 fish of 7 species caught in 2012 when the habitat was still quite bare following restoration. These figures compare with 158 fish of 9 caught in a pre-restoration survey in an immediately adjacent reach. Fish density in the restoration site in 2013 was 11.7 individuals per 100m² compared with 5.7 per 100m² in the pre-restoration survey site. Standing crop was 568 grams per 100m² in the restoration site, a small increase on the 508 grams per 100m² recorded during the pre-restoration survey. Numbers of stone loach, bullhead, brook lamprey, brown trout, dace and gudgeon have increased compared with the pre-restoration conditions. Further monitoring will be undertaken in future years to understand more about how fish populations change in response to habitat improvements.
The low level shelves created at summer water level at the channel margins have been colonised by a diverse flora including water mint, water forget-me-not, brooklime and gipsywort. The river channel itself supports a number of typical chalk stream plant species including watercress, water starwort, lesser water-parsnip and whorl-grass. +
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2016 Pre-intervention data:
Water Quality Sampling Summary (January - May 2016)
Sampling Locations:
1. Manhole at the top of Grove Park ditch
2. Inflow to Grove Park ditch proper
3. Outflow from Grove Park ditch into the Quaggy River
Results:
Nutrients:
1. Nitrate-nitrogen (NO3-N):
- Classified as good in all locations.
- Highest concentration: 5.25 mg/L (manhole).
2. Ammoniacal-nitrogen (NH3-N):
- Rated good at the manhole and ditch inflow, very good at the ditch outflow.
- Highest concentration after a long dry spell.
- Decreases from manhole to outflow due to nitrification cycle.
3. Total Nitrogen:
- Not monitored by WFD but poor according to European Nitrogen Assessment (ENA).
- Highest at the manhole (max: 14.2 mg/L, avg: 9.0 mg/L).
4. Phosphate (orthophosphate):
- Rated poor at the manhole, moderate in ditch locations.
- High variability in the manhole.
Heavy Metals:
1. Lead:
- Present in all samples, highest in the manhole (max: 0.4 mg/L).
2. Zinc:
- Below detection limits in ditch samples, present in manhole samples (avg: 0.3 mg/L).
3. Cadmium:
- Below detection limits in 50% of manhole samples, present at avg: 0.04 mg/L when detected.
4. Copper:
- Present in manhole samples, some ditch inflow, minimal ditch outflow. Max: 0.6 mg/L (manhole).
Other Parameters:
1. pH: Good in all sites.
2. Conductivity: No significant change between sites.
3. Coliform Bacteria: Improved from poor (manhole) to good (outflow).
4. BOD5 (Biochemical Oxygen Demand): Rated poor at all sites, slight improvement from manhole to outflow.
Post- intervention monitoring
ZSL Urban Wetland Monitoring Initiative
Chinbrook Meadows wetlands will host a trial citizen science project to monitor the health of the ponds. Developed by ZSL, the monitoring initiative will began in August 2024. +
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3 years monitoring to reduce alloctone species recolonisation. +
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5. Monitoring
Fish monitoring is taking place upstream and downstream of the new fish pass at Langsett. Yorkshire Water have also tagged fish to see if they approach the weir and what time of year. Walkover survey has been carried out with Yorkshire Water, Don Catchment Rivers Trust and the Environment Agency between Langsett and Underbank to identify issues and possible solutions. Monitoring will also be done before and after actions in the next water industry National Environment Programme. +
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<b>Five monitoring methods</b><br>
Expert opinion and observation drawing upon in-house geo-morphological expertise<br>
Habitat mapping survey<br>
Fixed point photography survey (manually taken and via time lapse cameras)<br>
Invertebrate surveys (planned, as of May 2014, as easement works are currently being undertaken on Kirklees Brook by Irwell Rivers Trust)<br>
Fisheries survey (planned, as of May 2014, as above)<br> +
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<b>Multi-partner monitoring strategy</b><br>
Coordinated by the River Restoration Centre and the London Borough of Barking and Dagenham, a monitoring strategy was set-up during the conception stage of the project with a range of targets across four thematic areas to assess the success of the project in a clear, scientific and transparent way. The four themes were:<br>
• Climate change<br>
• Natural environment (aquatic)<br>
• Natural environment (terrestrial)<br>
• People
The 'SMART' framework was used to set targets that were Specific, Measurable, Achievable, Relevant and Time based. These targets were agreed by the project Steering Group and were designed to incorporate the River Restoration Centre's monitoring guidance document (PRAGMO) http://therrc.co.uk/rrc_pragmo.php where appropriate. The strategy reflected monitoring activities related primarily to Phase 1 works (2011/2012) which included river restoration, habitat creation and general landscape improvements. It also included targets for the community engagement project, ‘Wild at Heart’ which was delivered in the park concurrently. The monitoring document was identified the overall aims for each theme and a list of individual targets were specified and prioritised in terms of cost, achievability and relevance. Information including what should be measured and existing data was recorded. The programme of monitoring actions for each partner was identified using a Gantt chart and this was updated throughout the monitoring programme to reflect data collected. Delivery of the strategy was overseen by the River Restoration Centre to ensure that all responsible monitoring partners collected their data in a timely and consistent manner. Data was held in one central inventory which was made accessible to all project partners.
<i>Data collected</i><br>
The monitoring strategy were delivered by different individuals and organisations of the Mayesbrook partnership. The 'climate change', 'people' and 'natural environment (terrestrial)' components of the strategy were led by the London Borough of Barking and Dagenham. With grant funding from Natural England (the Wild at Heart project), the Council employed a full-time ranger, between 2011 and 2013, to organise events for local people, coordinate volunteers and collect monitoring data. Data was collected to indicate the resilience of restored park features and flora to climate change. The change in area, condition and habitat suitablity of acid grassland, meadow grassland and woodland habitat was collected as well as number of birds and bats observed. From a social science perspective, the diversity and abundance of park users; an increase in outdoor learning and engagement; participation in volunteering; and public satisfaction was gathered to capture the project's impact on local communities and park visitors. The 'natural environment (aquatic)' component was delivered by the Environment Agency with Nick Elbourne, a part-time M.Sc. student at Cranfield University. Geomorphology, river habitat, water quality, macro-invertebrate, macrophyte and fixed point photography data was collected between 2011 and 2013. Some comparative baseline data was available from 2008/2009.
<i>Results</i><br>
Geomorphology and channel adjustment:<br>
• In summer 2012/ spring 2013, the majority of restored sections showed an increase in the abundance and diversity of habitat and flow types (compared to baseline River Habitat Survey data from 2008 and 2009).<br>
• Low rainfall and below average flows (drought-like conditions) in 2011/12 undoubtedly limited the regrowth of macrophytes (after physical works). The backwater and SUDs in the middle reach were planted up in places by volunteers.<br>
• A scoring method was trialed to score all fixed point photos (before, during and after restoration) on the observed naturalness of habitat and vegetation within the river corridor. The majority of fixed point 'scores' peaked in summer 2012 or spring 2013 after restoration (note: photos were taken on a quarterly basis between spring 2011 and spring 2013).<br>
• There was relatively insignificant change in the topography and chainage of cross-section surveys, collected bi-annually at 12 transects in the middle (6) and lower (6) reaches between autumn 2011 (immediately after new channel excavated) and spring 2012 (eighteen months post works). However there was evidence of evolving in-channel features in parts of the middle reach and natural gravel movements in the upper reach (see Image Gallery).
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==Success Criteria==
In the original bidding document a value for the minimal increase in spawning habitat was given, but the exact value is not known. There was also a target for increasing hydro-morphological diversity, but no exact value was given. No other clear qualitative or quantitative success criteria for other hydro-morphological, biological or flood protection targets were defined for the project.
''Pre-restoration monitoring''
In Seven Hatches, a detailed pre-restoration monitoring scheme was implemented. The detailed assessment method consists, namely physical biotope mapping, river corridor survey, macrophyte survey, cross-sectional mapping, depth/velocity/substrate survey, fisheries survey and repeat fixed point photography. The exact methods are described in the Monitoring Protocol.
''Post-restoration monitoring''
The post-restoration monitoring occurred 18 months after the project was finished. The monitoring methods were the same as the pre-restoration assessment.
Separate from the LIFE project in Seven Hatches some invertebrate monitoring was conducted before and after the measures, but the results of this survey was not reported in the project reports. +
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A 20-year monitoring programme has been implemented in 2014 to review the long-term biological and geomorphological components of the river ecosystem, including invertebrates, fish, riparian vegetation, physical habitat and channel morphology, and flow gauging.
The achievements in restoring the habitat and improving water quality were highlighted by monitoring reports carried out by Centre for River Eco System Science (CRESS) at Stirling University, Nith District Salmon Fishery Board (NDSFB) and Environ UK.
Macro-invertebrate Surveys
CRESS conducted surveys of benthic macro invertebrates from upstream, downstream and within realigned sections during October 2012 and October 2014 which highlighted:
• Diversity of macro-invertebrate fauna present (66 species from 48 different families) is consistent with a small tributary in good ecological condition and the taxa identified indicates good water quality
• Sample richness increased from 15 to 33 showing a significant improvement in two years as the river naturalised (120% increase in sample richness)
• The community structure was analysed using Shannon’s index of diversity, statistically showing negligible differences between the realigned habitats and the good quality controls upstream and downstream.
• The median Ecological Quality Indices of all samples was 0.95 - a score at the top end of ‘good ecological status’
NDSFB Electrofishing Survey
The results of the first survey highlighted:
• The channel has performed in a completely predictable manner and fish had utilised this section of river channel as a spawning site.
• Salmon fry increased at each of the six survey locations by an average of 21 individuals since 2012
• Two trout parr found in the realigned section in 2012, with 12 found in 2014 - a promising increase of 10 due to the general low abundance throughout the entire Nith system
• Fish densities of juvenile salmonids compared favourably with other Nith sites surveyed during 2014 (41 in total)
• Salmonid species of fish migrated through the diversion channel and successfully spawned upstream, within and downstream of the diversion channel
• Parr aged salmonids have taken up residency within the diversion channel
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A Morph River Condition assessment survey was carried out before with a follow up survey later in the summer and a further one in a year. Ecological surveys also carried out prior to project will be compared to surveys to be carried out next year to assess ecological impact. Results are expected to show a significant improvement in habitat and ecology along the restored 1km stretch. Drone video footage was recorded before and afterwards showing the extent of the works and the increased water storage capacity of the newly instated inset floodplains. Fixed point photography of the floodplain over time will be used to study sediment deposition. Phosphate levels will also be measured upstream between water treatment works and project site and compared with downstream of site to monitor ‘polishing’ effect of floodplain reconnection along the stretch. Baseline data from EA gauging stations should provide evidence of the volume of water storage made available by the and the possible reduction of peak flows in Upper Witham system. +
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A Water Quality monitoring programme is in place with Thames21, measuring parameters such as:
- Dissolved Oxygen and Biological Oxygen Demand
-Nutrients (nitrates, phosphates and ammonia)
- Heavy Metals: The concentration of heavy metals in the brook is indicative of road runoff. High levels of heavy metals can be damaging to wildlife, and may cause difficulties in the development of wildlife. The wetlands and swales will help to immobilise these by intercepting road runoff before it enters the stream.
In addition, London Borough of Enfield has commissioned Ecological Assessments to monitor current species and species diversity as the project advances +
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Reactivating river dynamics in the Vieux-Rhône River (non-navigable section) at Cornas, Roubion and Petite Île +
A brief ecological characterisation study was carried
out prior to the work. Following the work, a complete
ecological monitoring programme (vegetation,
birds, amphibians, odonata, fish) was initiated
as part of the overall authorisation procedure.
The year 2012, the year following the end of the
work, was selected as a reference point.
In September 2012, the Compagnie nationale du
Rhône initiated monitoring of the fish compartment
in the three pools on the Cornas site. The
monitoring will continue until 2016.
Birds, odonata, amphibians as well as the terrestrial
and aquatic vegetation are monitored by a consulting
firm. The annual campaigns will also be pursued
from 2012 to 2016.
For the time being, only preliminary results have been
published because the available data concerns only
the first year of monitoring. The general idea behind
the work to reactivate river dynamics is to initiate a
hydraulic and geomorphological process using the
energy of the river and its floods. The desired ecological
changes and improvements will become visible
following floods and over a fairly long time span.
The data from the geomorphological monitoring
are still being analysed, however some changes are
already visible. For example, signs of river dynamics
have been observed on two sites (Cornas and Petite
Île) during annual floods.
The fish community in the pools is the product of the
fish trapped by the floods in May and June 2012 and
that survived over the summer. The most common are
smaller fish (carp, bitterling, etc.) and juvenile bleak,
roach and bream.
In terms of terrestrial and aquatic vegetation, a strip
of helophytes has developed on the exposed banks,
where a number of indigenous species (Ranunculus
sceleratus, Najas marina, etc.) have appeared.
At Cornas, wetland vegetation has developed in
conjunction with pioneer species and undesirable species
(Japanese knotweed) along the channel.
Studies on odonata revealed the presence of a dozen
species, including Gomphus simillimus and Coenagrion
mercuriale, the latter being protected nationwide.
There are indications of amphibian reproduction and
various species (natterjack toads, common toads and
midwife toads) have been observed.
A brief pre-works report was drafted in the framework
of the preliminary study. It contained topographical
measurements and an analysis of the terrestrial
vegetation in the side channels that were
slowly filling in.
Following the works, ecological monitoring by a
consulting firm was carried out over four years from
2009 to 2012.
Monitoring addressed the physical compartment,
e.g. with topographic, temperature and physical-chemical
surveys, and the biological compartment
with an analysis on phytoplankton, zooplankton,
fish and the aquatic and riparian vegetation. An
analysis on visits to the site and on site maintenance
(number of visits, damage done to installations, etc.)
was also carried out.
The topographic profiles prepared in 2009 revealed
a high level of local sedimentation causing a narrowing
of the side channel. On the basis of the results
from 2010 to 2012, this sedimentation is apparently
caused by readjustments on the worked site where
successive floods and the wakes of ships even out the
profile of the side channels.
The modifications made at the foot of the embankment
limited erosion as planned.
However, the analysis also revealed that the wakes
of ships produced effects in the side channel and represented
a significant pressure on the environment
by limiting biological development. Fine sediment
in the side channel was regularly resuspended in the
water by the wakes, which may reduce the environmental
value of the area.
Monitoring of the fish populations revealed an increase
in the number of species caught in the side
channel, from 17 species in 2010 to 21 in 2012. In
the spring, the time of rising water levels, the side
channel remains a calm environment that is favourable
for small species. At the beginning of the fall
of 2012, the side channel was home to a diversified
and more abundant community than in the spring,
due to the hydrology of the Saône and to the development
of the grass beds that enhanced site attractiveness.
In addition, a number of fish-eating species
were noted, including perch, pikeperch and pike,
re-observed for the first time in 2012.
The aquatic vegetation in the continuously filled
pond underwent considerable change with respect
to the observations made from 2009 to 2011. The
dominant Nuttall’s pondweed, an invasive alien species,
gave way to significant development of rigid
hornwort, a native species. The number of inventoried
plant species remained virtually identical. A
stabilisation process would seem to be under way in
some of the side channels.
The VNF technical department and the town are satisfied
with the operation. However, the large number
of visits to the site have resulted in vandalism
creating pressure on the vegetation and incurring
additional costs for maintenance and the installation
of systems to limit access.
A fish survey was carried out before the structure was completely removed and this data will be used to compare future surveys and monitor the effects this project has had on the existing fish communities and whether the work has increased the diversity of species present in this stretch of the Adur. +
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A fixed point photographic record has been set up and this, together with visual inspections, will be used to monitor the integrity and performance of the in-stream structures. A programme of fine sediment sampling and Wolman Pebble Counts to monitor the coarser riverbed material has also been established. In combination they will determine and record changes to river morphology as the result of the works. The established crayfish monitoring site at the bottom of the reach is already surveyed every 2 years and this will give an indication of the impact of the scheme on crayfish numbers. Finally additional ongoing invertebrate sampling will identify any ecological and water quality changes that occur. +
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A good coverage was achieved across all three waterbodies with nearly 80% of their total length covered by walkover surveys. This resulted in 293 recorded pollution sources, whether observed or potential. The vast majority of pollution sources noted only showed potential for impacting the waterbodies, with comparatively few (9 significant) having a significant impact on over 100 metres of watercourse. +
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A heritage audit was commissioned to assess the cultural and historic significance of the 177 weirs recorded and heritage assets along the 10km of the riverine SSSI in order to inform restoration proposals. The report provides a record of the built structures and includes an assessment of their historical significance along with recommendations for recording and interpretation.
A River Habitat Survey (RHS) has been undertaken over the last two years to provide an update to the last one undertaken in 2012. This will provide a useful baseline for future RHS post weir removal on a reach basis and throughout the entire SSSI.
A specific ecological monitoring strategy has been put in place to supplement routine EA monitoring locations within the SSSI. Additional fish and invertebrate surveys will be undertaken pre and post weir removal. +
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A key component of this project is to rehabilitate and enhance the LoWs including Fen Meadow and Wet woodland. Therefore any monitoring will focus on any improvement is this habitat. There will also be fixed point photography, before, after and as the site develops. +
2
A monitoring Plan has been produced and a baseline of pre works data was collected. This includes biotype mapping, sediment sampling, electro fish survey, RHS Survey and fixed point photography +
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A monitoring process was developed before the first stage of the removal.
Bathymetries were first performed in the reservoir to determine the amount of
sediment accumulated.
Two geomorphological monitoring reports were made. The first one, carried out in
2013, was a morphological characterization in the study section (upstream and
downstream of the dam) prior to the first stage of the removal. Following the first
stage, two monitoring campaigns were carried out (September 2013 and April-June
2014). Besides, a second monitoring campaign was conducted after the second stage
of the removal.
The monitoring process determines that a movement of the sediments is observed
after each phase of action, depending on the flow rate of that year. The amount of
sediment mobilized after the first stages of the removal is higher than the sediments
mobilized prior to the removal of the dam.
It can also be concluded that water quality has not been altered after the first stages of
the removal.
Habitat and species studies were also conducted because the Inturia dam is an
impassable obstacle to the movement of fish. The fish community in the Leitzaran
River is: Brown trout (Salmo trutta), Atlantic salmon (Salmo salar), barbel (Luciobarbus
graellsii), Adour minnow (Phoxinus bigerri) and eel (Anguilla anguilla). Trout is
considered a good indicator in this river.
Within the monitoring process, a 3 km long reach (2 km upstream and 1 km
downstream) was monitored by placing 11 sample points in which it was possible to
verify the evaluation of the river by taking images at different moments of the year.
Monitoring has been carried out after the fourth stage of the removal as well, but this
data is not yet available.
It is considered that the proposal of removal in different stage is adequate and it
seems correct to apply this methodology in actions of similar characteristics.
It is also considered adequate to leave a period of time between each stage of the
removal so that the sediments can be exported through the river by means of the
floods.
Working in stages also avoids impacts on ecosystems. The fish populations of the
Leitzaran River have endured well the works.
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A monitoring program for fish, benthos, plant life and birds during 2016 - 2018. Natural recovery is observed for all species groups. Grazing domestic animals cause some erosion that limit establishment of forest, and soil erosion into the river might be limiting for benthos. +