Figure 1: Map of Estuary edges sites pinpointing Mill Pool, River Roding; inset graphics include Google Earth aerial photo of site and chart extract of Site (heights in metres relative to Chart Datum).
~9‰ at creek mouth (open estuary) (Wade, Hawes and Mulder, 2017)
Date of construction
1.6m (Half tide weir)
Percentage of area accreted above design level
Degree of exposure to waves:
Degree of exposure to currents:
Low (open basin reduces fluvial currents)
Max wave height
1 in 7 normal to bank, near horizontal parallel to bank
Average Whole Structure lifespan
Table 1: Site conditions summary.
1.2 Site Characteristics
Located approximately 3.3km upstream of the mouth of the tidal River Roding (also known as Barking Creek) at a location known as Town Quay.
This site is unique in that a half tide weir approximately 0.5km downstream means that the tidal zone is narrowed vertically and the natural low tide level is never experienced.
This site is used by…
This site is sheltered from vessel wake and there is no fetch to cause wind waves.
Although around 1/3rd of the River Roding flows through urban north east London, the middle and upper catchment is rural. It is therefore not as ‘flashy’ as some of the south London rivers which are predominately urban. Any residual fluvial currents are likely to be reduced further by the wide basin at Town Quay.
The salinity of 9‰ at the mouth of Barking Creek but will be significantly lower here due to the fluvial influence.
Previous the site was a decaying concrete slopes with an invasion of common weeds and relatively low ecological value.
1.3. What the developers did
Works involved the breaking out of the existing concrete revetment and construction of 3 L-shaped terraces with a maximum slope of 1 in 7 using wooden palisade.
Terraces were permeable with no concrete beneath.
The upper two terraces were planted with locally collected riparian seed.
Pre-planting was conducted: Bottom terrace was planted with Sea Club-rush and Common Reed.
The immediate area of river in front of the terraces in the creek shallow with silt and mud and adjacent lock gates.
The lowest ledge of the terrace has water on between eleven hours in small tides to all the tidal cycle in larger tides, while the top of the lowest terrace is covered between in ten hours small(neap) and 27 minutes in large (spring) tides respectively. The top terrace of the three highest point is inundated, between eight and nine hours on neap and spring tides respectively.
Figure 6: cross section of elevation of constructions (heights in CD)
Adjacent Site/Comparable Site:
The next nearest site where biodiversity surveys were conducted was Barking Creek, Beckton Sewage Treatment works 2 km down the Roding. However, the salinity is likely to be significantly higher at Beckton and the style of the estuary edge feature is very different (naturalised set back versus an intertidal vegetated terrace). A more representative comparable site may be therefore be Deptford Creek Thanet Wharf which although 11 km up-estuary and therefore less saline is a very sheltered creek location and south east facing in orientation.
Flora wasn’t measured at the site. See Deptford Creek Thanet Wharf for a comparable site where it was measured. Although flora wasn’t measured by an ecologist at this site, it is notable that buddleia has taken over along the upper terrace on one side.
100% of the accretable area has accreted with sediment above the design level (Figure 4).
Figure 4: Schematic showing geomorphology and basic ecology.
Contributing reasons for this include:
Sheltered from both waves and currents.
Figure 5: Mill Pool, River Roding, looking west, before enhancement in 2006. Source: Estuary Edges 2008 document.
Figure 6: Mill Pool, River Roding, close up of the western section of the terraces in summer 2007 (1 ¼ years after construction) showing well established vegetation. Source: Estuary Edges 2008 document.
Figure 7: Mill Pool, River Roding, looking west in Summer 2017 (11 years after construction) showing continued well established vegetation but take over by buddleia in one corner. Source: Environment Agency.
Figure 8: Mill Pool, River Roding, looking east in Summer 2017 (11 years after construction) showing continued well established vegetation but take over by buddleia in one corner. Source: Environment Agency.
Figure 9: Mill Pool, River Roding, looking north west in Summer 2017 (11 years after construction). Source: Jacobs/TEAM2100.
The site is not easily publicly accessible and therefore no social surveys were completed as part of this review.
A few pieces of litter observed but the terrace was generally clear (see Figures 7 and 8: No better photographs exist to demonstrate the lack of litter).
Contributing reasons for this include:
Sheltered from both waves and currents and therefore no reason for litter to get swept in.
4.3 Safety and Navigation
This site has no signage or lights. In the event the area is frequented by craft, there is a risk that the sites lower levels could catch vessels and the proximity of lock entrance. Having reviewed the site in situ, it is now felt that warning to passing traffic, however infrequent, would have been beneficial.