Property:Monitoring surveys and results
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G
Nitrogen and phosphate are essential for river life but in excess they cause eutrophication. This results in reduced levels of oxygen in the water and may cause toxic algal blooms. Nitrate may be present as ammonia, nitrite or nitrate (measured together as Total Nitrogen), but nitrate is the most stable form. Our water quality monitoring has shown that the SUDS basins are effective at removal of Total nitrogen, nitrates and phosphates. Water quality improves between sampling location 1 (the inflow to the SUDS) and location 2 (outflow from the SUDS), particularly in total nitrogen (dropping from 10mg/l to 6mg/l) and nitrate (dropping from 13mg/l to 7mg/l), bringing water quality within acceptable guideline levels (as defined in EA General Quality Assessment, Water Framework Directive 2014).
Coliform bacteria derive from faecal waste and are an indicator of pathogens in the aquatic environment. They enter waterways from misconnected toilets, sewage treatment plant overflow, domestic pets and agricultural run off. The SUDS basins are extremely effective at removal of coliform bacteria. Water quality improves between sampling location 1 (the inflow to the SUDS) and location 2 (outflow from the SUDS), with coliform counts dropping from approximately 1400 total coliform colonies to approximately 400 total coliform colonies, bringing water quality within acceptable guideline levels (under EC Bathing Water Directive).
Invertebrate surveys have also been carried out as part of this project. A masters student from Kings College London (KCL) undertook research into invertebrate populations at each of the project sites. Linking the invertebrate survey results to water quality data, the student predicted the impact/ potential impact of each of the SuDS/wetland schemes on population sizes and diversity over time. There was no existing data on invertebrates for the catchment before research was carried out. As predicted the invertebrate survey confirmed findings of poor water quality, with pollution sensitive taxa very badly represented. The study concluded that the SuDS have the potential to improve water quality and ecological outcomes downstream, but far greater efforts in reducing pollutants from vehicle use and misconnections will be required to resolve the problems of urban diffuse pollution.
Nitrogen is essential for river life but in excess can cause eutrophication. This results in reduced levels of oxygen in the water and may cause toxic algal blooms. Nitrate may be present as ammonia, nitrite or nitrate (measured together as Total Nitrogen), but nitrate is the most stable form.
Reed bed: The recently installed reed bed is already proving effective at removing nitrogen compounds from the water. There is a significant difference in water quality between the inflow above the reed bed (sampling location 1) and the sampling location immediately the other side of the reed bed (location 2) in total nitrogen, nitrate and ammonia. Total nitrogen drops from 7mg/l to 5mg/l, nitrate from 13mg/l to 4mg//l and ammonia from 1.6mg/l to 0.5mg/l. The improvement in water quality through the reed bed is greater than the improvement observed in the body of the lake. This is because the difference in water quality is larger between sampling sites 1 and 2 compared to between sites 2 and 3 (the lake outflow).
Wetland basin: The wetland basin is effective at water quality improvement because it prevents polluted water from two drains (sample locations 5 and 6) from entering the stream at site 4. Water entering the infiltration basin from the de-culverted pipe at sampling site 6 is consistently outside of acceptable concentration ranges specified by the Water Framework Directive. Ammonia is consistently present in levels deemed harmful to aquatic life in both inflow pipes (sample locations 5 and 6). Water only flows out of the wetland basin in storm conditions so it effectively prevents polluted water from entering the stream.
Coliform bacteria derive from faecal waste and are an indicator of pathogens in the aquatic environment. They enter waterways from misconnected toilets, sewage treatment plant overflow, domestic pets and agricultural run off.
Reed bed: The reed bed is an effective remover of coliform bacteria, reducing the coliform colony count to within guideline limits (under EC Bathing Water Directive)immediately after the reedbed (sample location 2), dropping from approximately 1100 total coliform colonies to 50 total coliform colonies.
Wetland basin: Water entering the wetland basin from the culverts at sampling sites 5 and 6 contains high counts of coliform bacteria, that are outside of guideline limits (under EC Bathing Water Directive). This is prevented from entering the stream (sample location 4) because water only flows out of the wetland basin in storm conditions.
F
No monitoring was undertaken.
Observation of morphological change upstream of the opened hatches to determine level of future in channel works required. +
R
No post project monitoring has been done. +
No pre-project assessment was carried out. In 2007, electrofishing was conducted by the National Office for Water and Aquatic Environments (ONEMA), showing a good recolonization of the restored stretch by fish; juveniles of trout, target species in the river, were also found. Since then no other monitoring has been done or is foreseen. +
S
None to date +
R
On 3rd October 2014 the first salmon ascended the Culter Dam in over 250 years, thanks to a fish pass we installed on the dam just days earlier funded entirely by businessmen Martin Gilbert and Stewart Spence. This dam, at Peterculter, is the largest man-made obstruction on the River Dee.
*2014 Season: Numbers up the fish pass to date (June 2015): 43 Salmon 69 Sea trout
Why install a fish pass on the Culter?
The fish pass has opened up 76 miles of habitat in the previously inaccessible Culter burn for migratory salmon and sea trout to re-establish natural populations in.
Only the lowest one mile of burn is below the dam and so accessible to salmon and sea trout. The spawning and rearing habitat in this part of the burn is fully utilised, resulting in high juvenile fish densities. High juvenile fish densities mean lots of competition and higher mortality rates. Creating more rearing habitat for juveniles will result in lower mortality rates and so higher fish production.
Once habitat restoration work is completed in the Culter catchment we expect to see an additional 1,500 salmon returning to the Dee each year.
These salmon may be available to the catch and release rod fishery as far up river as Banchory, as our radio tracking studies show how fish may wander up to 20km upstream from where they eventually spawn.
Monitoring Fish Pass Success
A Vaki fish counter is installed at the top of the fish pass to record how many fish are using the pass to ascend the dam. The counter records the length of each fish. We assume that all fish longer than 50cm are salmon, fish between 30 and 50cm length are sea trout and fish less than 30cm are brown trout. In practice, there is some size overlap, particularly between small salmon and large sea trout. Our scale data show we would expect 6% error in these classifications. +
On a comparable length of watercourse that has been included in all surveys since 2007 (as the survey area has increased over the years) the approximate length of pennywort beds totalled 10.3km in 2009 and 1.6km in 2012, this is a significant decrease in the occurrence of this species.
We are already seeing the impacts of our work. Huge areas are now clear of Pennywort and the river is visible again. We have seen water lilies return in Abbey Park and fish are able to migrate as the water column is clear of the plant. Clearing the Grand Union Canal has made it much more accessible for boats. +
T
One of the main objectives of the project was to deliver on the actions identified in the Test & Itchen Strategy. One action was to restore the stretch through weir removal to restore natural function. This has been achieved.
Our objectives to restore natural chalk stream characteristics, remove obstacles, reduce/eliminate the need for human intervention and reconnecting the river within the floodplain are clearly demonstrable. The impounding structure and associated sluices have been removed and a characteristic gradient and sediment transport has been restored. The lake sediments have been off-lined from the channel system removing the potential phosphate enrichment of the downstream watercourse.
The final objective was to maximise the physical and ecological diversity. Fish surveys, invertebrate and crayfish monitoring have been carried out along with HABSCORE surveys which were conducted in order to monitor the physical habitat and track the changes that will occur as the channel becomes more established over time.
Jonathan Cox has provided information for the appropriate assessment and an assessment of the SSSI and the protected species. We also had an extended phase 1 Ecological Appraisal carried out by the Hampshire & Isle of Wight Wildlife Trust (HIWWT).
Prior to this project this section of the Cheriton Stream had been heavily modified leaving a legacy of impoverished channels, a silt filled lake and a river that was disconnected from its flood plain. Please see the current site plan and proposed site plan drawings attached with this application.
A significant achievement was met when the owners of Tichborne Park agreed to a significant landscape change to the park surrounding their grade II listed home. The lake had become a burdensome feature that would require significant resources to maintain.
Once the agreement of the owners had been secured the designers and stakeholders of this scheme commenced with designs that aimed to restore a naturally functioning river channel. Some constraints existed, perhaps the most significant being the owners request that the river flowed close to the house to compensate for the loss of the lake. This entailed a diversion away from the natural path of the river for a small section of the project area. In all other areas channels were either created, reinstated or restored so that a natural path was achieved.
Surveys have revealed a site now dominated by wild brown trout with eel, lamprey, bullhead and stickleback also present. Invertebrate monitoring has shown an abundance of gammarus, mayfly, stonefly and caddisfly to name a few.
Unfortunately, with the untimely death of Anthony Louden, it was deemed to be inappropriate to cover the project widely in the press as the family were already under great pressure.
The extent of the project’s achievements in restoring the natural state and functioning of the river system is illustrated in the following table:
Revived Relic
Channel (m) Restored Channel with increased flow volume (m) Channel with Restored Gradient (m) Channels preserved as backwaters / seasonal flow channels (m)
Upstream meadow 180 190 185 280
Lower meadow 195 75 260
Total 375 265 185 540
Cloudbase Aerial Art, a specialist aerial media company, have successfully taken extensive before and after photographs through the use of drones.
S
Ongoing fish surveys are being undertaken at this location, as well as habitat assessment. +
T
Our performance in delivering against the whole CMP is reviewed every 4-5 years, and a popular review document is produced that measures progress on the main targets within.
With each project we monitor at different levels. At its most basic we use fixed point photography. This combined with the monitoring carried out by the agencies for WFD classification purposes and site condition monitoring, gives a good indication of how the status of the watercourse has changed at the landscape scale over time. (e.g good ecological status; favourable site condition).
At the other end of the scale we carry out very detailed monitoring such as on the Eddleston and the Bowmont Water. On the former we have installed, in conjunction with Dundee University, SEPA, Forest Research and British Geological Survey, one of the most detailed hydrological/groundwater monitoring networks in the UK. This is complemented by detailed hydro-geomorphological and ecological surveys (in-stream habitats, sediments, invertebrates, macrophytes, electrofishing), so we accurately assess the effects of each intervention and the totality of all the restoration work we are doing at both reach and catchment scale. +
C
Our project is open ended with events being held every 3 weeks. Although the amount of rubbish we clear from the waterways is reducing in terms of large items, we still get a lot of plastics swept down from further upstream. We know we have made a difference and changed habits of people in Cardiff who used to use the rivers as an alternative rubbish bin, we have not been able to influence those further upstream. We have over 350 volunteers on our database and each event attracts between 20 and 30 volunteers, even in the depths of winter and irrespective of weather.
Since 2009, we have held 121 events and worked approximately 4930 volunteer hours, collecting the following :- 3307 bags of rubbish, 157 trolleys, 187 car tyres, 144 traffic cones, 57 bicycles, 13 motor bikes and an estimated 22 tons of rubbish and 7 tons of scrap. +
A
Over 1 hectare of nationally important wetland habitats will be restored - benefiting wildlife such as otters, kingfishers and dragonflies. A key feature of the 400k project was the successful partnership with Thames Water, the University of Reading, Farley Estate and Arborleigh Angling Club. Over 60 volunteer days were given +
T
Periodic visits to the site will be made to help ensure grazing management is ideal for the conditions that develop. Tree growth or failure to grow should be monitored. Repeat photographs are recommended for the archive. Biological monitoring may be of limited value if pre-conditions have not been recorded. The creation of an accurately scaled diagram of the location and extent of each feature will also facilitate ease of repeating the As Built mapping survey to ascertain how the channel and the installations respond to the various flow and non-flow conditions and how the channel evolves physically and ecologically over time. +
R
Phosphorus
The phosphorus concentrations within Rookery Brook showed a general increase to a peak (around 0.7 mg/l) in late summer (August, September) before reducing to approximately 0.25 mg/l in December and January. A slight worsening in quality is observed between upstream and downstream samples.
Samples from the northern tributaries of the Rookery Brook showed a similar but more pronounced fluctuation. Concentrations rose from between 1.2 to 2 mg/l in July 2015 to 2.2 to 5.2 mg/l at their peaks in September through to November. The southern tributary recorded lower phosphorus concentrations, peaking at 0.7 mg/l in October 2015 (similar to Rookery Brook itself).
In relation to the Water Framework Directive (WFD) monitoring indicated that the Rookery Brook northern tributaries are of ‘poor’ water quality with respect to phosphorus and is itself of ‘moderate’ quality. The southern tributary varied from ‘moderate’ to ‘good’.
Nitrogen
Concentrations of nitrate and other nitrogen compounds, including ammonia, have also been monitored. Ammonia is indicative of sewage effluent, farmyard slurry or manure type of contamination and within the Rookery brook itself varied from 0.2 to 1.5 mg/l classified under the Water Framework Directive as ‘high’ to ‘moderate’ quality. The poorest quality was recorded at the upstream sample point in August. However, peaks also occurred at the mid-catchment sample point in October.
Within the northern tributaries ammonia peaks of between 4 and 20 mg/l were recorded in September and October 2015, which is classified as ‘poor’ quality under the WFD. Again the quality of the southern tributary was better generally being ‘moderate’ to ‘good’.
Nitrate concentrations were generally below the NVZ/Drinking Water Standard threshold of 50 mg NO3/l. However, all the watercourses (Rookery Brook and the northern and southern tributaries) exceeded the threshold in December 2015 to January 2016 with concentrations up to 68 mg NO3/l being recorded.
This data sets out the background or baseline water quality for the lower Rookery Brook catchment prior to the installation of any mitigation measures to improve water quality.
Q
Photographs pre-works +
P
Photographs pre-works +
H
Photographs pre-works +
P
Photographs pre-works<br>
Fisheries survey<br>
Photographs post-works +
L
Photographs pre-works<br>
Photographs post-works +