Local Plan 2011-2031 Proposed Submission Draft

Site BA1 does NOT meet any of the aspirations laid out in bullet point 2 of 'vision'

New development will have contributed to the creation of sustainable communities.
- A near doubling of the size of Baldock in site BA1 is NOT sustainable, it makes another town with poor transport links and virtually no local shopping facilities.

These are safe, attractive and inclusive;
- Not attractive, being built on Green belt land which gives Baldock its character, and not inclusive, being divided from the rest of Baldock by the railway line.

well integrated into settlements;
not Well integrated, being divided from the rest of Baldock by the railway line and provided by transport links which are already congested.

respect local distinctiveness;
- Actually destroys local distinctiveness by building over a very large tract of open green belt land which gives Baldock its distinctiveness.

raise the standards of sustainable design and architectural quality;
- No comment

make a positive contribution to the local area;
- Gridlock on local roads and flooding in its rivers is not a positive contribution.

and ensure the protection, restoration and enhancement of valuable natural and historic resources.
- Building over a very large tract of open green belt land does none of these things.

Strategic sites will have been masterplanned in accordance with the guiding principles set out within this Plan
- Remove site BA1 because it meets none of these guiding principles.

"The River Ivel catchment is a fast responding catchment meaning it is vulnerable to flash flooding following a significant rainfall event." (Central Beds report CB/FLO/15/09003)

Currently (and for the last 60 years since my family have lived here) Radwell has NOT suffered from flooding, but in wet winters sometimes it does come close to it.

The proposed developments in Baldock plan to add c. 3200 new homes, all of which are in the River Ivel catchment. This infers the development is likely to significantly affect Radwell through increased water flows both from runoff and sewage treatment outfall.

Apparently no Surface Water Management Plan (SWMP) study has been conducted despite the fact that the proposal is to nearly double the size of the Baldock urban area which by any measure must represent a massive increase in flood risk to areas downstream of the catchment.

River flow at Radwell Mill has been measured to vary between 3.5 and 16 Megalitres(Ml)/day (oct 2015 - oct 2016, Affinity Water study).

Treated water:
In the absence of any alternative proposals, it is reasonable to assume the treated water from the developments will go into the River Ivel. On the basis of 2.3 persons per houshold (2011 census), annual water consumption of 110 m3 per houshold/annum (consumer council for water) and 3200 new households this represents an increased output of treated water into the Ivel of some 352 Ml per annum, increasing flow by between 6% and 27%.

Runoff:
"Developing a green field site may result in 10 times the runoff during extreme rainfall" (Woods-Ballard et al 2007). The plan mentions "Sustainable Drainage Systems (SuDS) and other appropriate measures" but these are in large part merely a 'buffer' of limited capacity and not capable of restricting flow for extended periods of wet weather when the river Ivel is already close to capacity. It is therefore easy to envisage that a development of this size is highly likely to lead to flooding in Radwell and other villages (eg Stotfold) downstream. This happened as recently as July 2015 and again in June 2016 when extreme rain events in Letchworth (c. 25mm in 90 minutes) overwhelmed Pix Brook and flooded houses in Stotfold.

25mm (c. 1 inch) of rainfall over 91 Ha is 22 Ml of water. The 5% runoff expected from the green field site would be 1.1 Ml, the runoff from the same area as residential development could be expected to be between 30% (6.8 Ml) and 60% (13 Ml) representing a potential increase of between 5.5 and 12.5 Ml of runoff in a single event, this will increase flow by between 78% and 157% representing a very serious risk of flooding.

Pollution:
Radwell lake is already deemed an area of "Wildlife and Nature policy 14" and we work hard to keep it nice. The massively increased runoff is likely to increase temperatures in our river, harming fish and other organisms; A sudden burst of runoff from a rainstorm can cause a fish-killing shock of hot water. Salt used to melt ice and snow on pavements and roads in the new developments will further contaminate our river.

Oil and other hard-to-monitor pollutants will get into our river from the newly developed areas. This already happened when the SuDS ponds associated with runoff from the A1(M) built in 1966 silted up after only 25 years of service and we began to see an occasional oil film (on one occasion a large quantity of it) polluting our river. Eventually the ponds were dredged at considerable expense because the silt was classified as hazardous waste.

I feel there is some scope for development (as there may be in other "category C" settlements) which may serve to take some of the pressure off building unsustainable 'mega settlements' like the ones proposed at BA1 and LA1

Both LA1 and BA1 are proposed on Green Belt Land described as 'North Baldock Chalk Uplands' charactized by its remote and open landscape.

"The reference to areas of remoteness is fully supported. The feeling of tranquillity is also a perceptual aspect of the landscape that should be protected wherever possible. Tranquillity provides relief from urban areas and benefits health and wellbeing, protecting any pockets of tranquillity is especially important in close proximity to highly developed areas." (comment letter from Paul Donovan HCC Spatial Planning and the Economy Environment Department 3 Feb 15)

In respect of BA1, the open nature of the area north of Baldock is fundamental to the character of the town, being at the foot of the Chilterns and the edge of the Chalk uplands. The development of BA1 will destroy this characteristic, and 'replacing' green belt by some new areas near Luton airport is no mitigation.

In respect of LA1, In 1902 Ebenezer Howard wrote in Garden Cities of Tomorrow: "Shall it build on the zone of agricultural land which is around it and thus forever destroy its right to be called a 'Garden City'? Surely not." LG1 as farmland is of vital importance in maintaining the green belt design of the world's first garden city. To erode this beyond the natural skyline boundary of the existing built up area would be a critical loss to Letchworth's integrity and therefore no developer could possibly satisfy Policy SP15 condition a,i "How the site will follow and implement Garden City principles".

It is also difficult to imagine how any development at a density of c.35 dwellings per Ha can possibly "implement Garden City principles" in any case.

This high density housing at LA1 will be especially deliterious to views from afar, eg from North Road between Radwell and Baldock and from the water tower at the junction of the A1 and the Langford Road where Letchworth is currently out of view in its own valley. It will become highly visible, and be a ruinous encroachment on the rural aspect of Letchworth from the North and especially to Radwell and its Wildlife area.

NPPF and Government statements
The Planning Minister in March 2014 reaffirmed NPPF priorities saying "Unmet housing need is unlikely to outweigh harm to the green belt and other harm to constitute the very special circumstances justifying inappropriate development on a site within the Green Belt"

NPPF requires Councils to protect the green belt when preparing their Plans. Para 14 states that the extent to which assessed housing needs are met should reflect constraints such as Green Belt. Guidance 1 re-confirms this.

NPPF says "The Government attaches great importance to Green Belts. The fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open; the essential characteristics of Green Belt are their openness and their permanence."

Radwell, a village 2 miles north of Baldock. Baldock is where residents of Radwell and other nearby villages go shopping and catch public transport services (train or bus). Site BA1 will make this much more difficult than it is now because the plan is inadequate.

Department of Transport statistics say car ownership 2014/15 in "Rural Town and Fringe" is 1.39. This suggests that with 2800 new homes in the proposed North Baldock development it will become home to c. 3900 cars and vans.

Travel to places of work:

2011 Census: "Method of travel to work England and Wales, 2011. Employed usual residents aged 16 to 74, plus passengers, is 62.6%" This equates to approximately an extra 2200 car movements from BA1 morning and evening.

So how is this traffic expected to get in and out of BA1? The plan envisages a single 'distributor road' with two exits, one to North Road, and the other over a new bridge over the railway to the A505 junction.

Going into Baldock: Whether you leave BA1 by either exit this traffic must cross the lights at the The A507/B656 Junction.

"The junction is operating close to the degree of overload where queuing could be an issue. With no land available to modify the existing arrangement to increase the capacity, it would indicate that any notable future developments would require new or amended junctions/ roads elsewhere in the local network to accommodate the additional traffic generated by them." [Feasibility report (Nov 2014)]

The "junction is currently running close to capacity and will be unable to accommodate additional development flows with its current configuration. ... Additional mitigation measures would therefore be required at this location which have not been identified or costed for." (comment letter from Paul Donovan HCC Spatial Planning and the Economy Environment Department 3 Feb 15)

Our empirical experience of taking children to the Station every morning and evening backs this up; North Rd can often be stationary back to Norton Mill Lane from where it takes more than 15 Min to get to the traffic lights. Indeed it is nearly as congested as when this was the Great North Road before the A1(M) was built in 1966, when traffic would occasionally back up as far as Radwell Lane.

Going into Letchworth or A1(M) south via Letchworth Gate:

"Key current congestion issues in the town include the area around Letchworth Gate and the A505 / A6141 junction" (comment letter from Paul Donovan HCC Spatial Planning and the Economy Environment Department 3 Feb 15)

NHDC's own information indicates the only reasonably uncongested routes out of BA1 are likely to be the A505 to Royston or North Road to J10 of the A1(M).

Travel to shopping:

The plan envisages "A new local centre along with additional neighbourhood-level provision providing around 500m2 (net) class A1 convenience retail provision and 1,400m2 (net) of other A-class floorspace" [Policy SP14 b] but this total provision for a proposed population of c.6500 people is barely 1/3 of the size of just one existing shop in Baldock. Tesco has a Net Sales floor space of 6,340 m2 [NHDC Appendix A Study Area and Existing Retail Facilities] and is already operating somewhere near its capacity at peak times.

All the nearby shops are either in the town centre, or Tesco, or are in Letchworth (Sainsburys, Lidl Etc) and to get to them all you must go through the junctions highlighted as either 'congested' or 'close to capacity' already.

It is certain that BA1 will cause such gridlock at the A507/B656 junction as to make access to Baldock from the surrounding villages to the North difficult or at times impossible. NHDC / HCC evidence states there is very little scope to improve it thus suggesting NHDC prefers BA1 residents to work and shop in Royston or Biggleswade. This is not a 'sustainable' solution.

Radwell, a village 2 miles north of Baldock. Baldock is where residents of Radwell and other nearby villages go shopping and catch public transport services (train or bus). Site BA1 will make this much more difficult than it is now because the plan is inadequate.

Department of Transport statistics say car ownership 2014/15 in "Rural Town and Fringe" is 1.39. This suggests that with 2800 new homes in the proposed North Baldock development it will become home to c. 3900 cars and vans.

"The River Ivel catchment is a fast responding catchment meaning it is vulnerable to flash flooding following a significant rainfall event." (Central Beds report CB/FLO/15/09003)

Currently (and for the last 60 years since my family have lived here) Radwell has NOT suffered from flooding, but in wet winters sometimes it does come close to it.

The proposed developments in Baldock plan to add c. 3200 new homes, all of which are in the River Ivel catchment. This infers the development is likely to significantly affect Radwell through increased water flows both from runoff and sewage treatment outfall.

Apparently no Surface Water Management Plan (SWMP) study has been conducted despite the fact that the proposal is to nearly double the size of the Baldock urban area which by any measure must represent a massive increase in flood risk to areas downstream of the catchment.

River flow at Radwell Mill has been measured to vary between 3.5 and 16 Megalitres(Ml)/day (oct 2015 - oct 2016, Affinity Water study).

Treated water:
In the absence of any alternative proposals, it is reasonable to assume the treated water from the developments will go into the River Ivel. On the basis of 2.3 persons per houshold (2011 census), annual water consumption of 110 m3 per houshold/annum (consumer council for water) and 3200 new households this represents an increased output of treated water into the Ivel of some 352 Ml per annum, increasing flow by between 6% and 27%.

Runoff:
"Developing a green field site may result in 10 times the runoff during extreme rainfall" (Woods-Ballard et al 2007). The plan mentions "Sustainable Drainage Systems (SuDS) and other appropriate measures" but these are in large part merely a 'buffer' of limited capacity and not capable of restricting flow for extended periods of wet weather when the river Ivel is already close to capacity. It is therefore easy to envisage that a development of this size is highly likely to lead to flooding in Radwell and other villages (eg Stotfold) downstream. This happened as recently as July 2015 and again in June 2016 when extreme rain events in Letchworth (c. 25mm in 90 minutes) overwhelmed Pix Brook and flooded houses in Stotfold.

25mm (c. 1 inch) of rainfall over 91 Ha is 22 Ml of water. The 5% runoff expected from the green field site would be 1.1 Ml, the runoff from the same area as residential development could be expected to be between 30% (6.8 Ml) and 60% (13 Ml) representing a potential increase of between 5.5 and 12.5 Ml of runoff in a single event, this will increase flow by between 78% and 157% representing a very serious risk of flooding.

Pollution:
Radwell lake is already deemed an area of "Wildlife and Nature policy 14" and we work hard to keep it nice. The massively increased runoff is likely to increase temperatures in our river, harming fish and other organisms; A sudden burst of runoff from a rainstorm can cause a fish-killing shock of hot water. Salt used to melt ice and snow on pavements and roads in the new developments will further contaminate our river.

Oil and other hard-to-monitor pollutants will get into our river from the newly developed areas. This already happened when the SuDS ponds associated with runoff from the A1(M) built in 1966 silted up after only 25 years of service and we began to see an occasional oil film (on one occasion a large quantity of it) polluting our river. Eventually the ponds were dredged at considerable expense because the silt was classified as hazardous waste.

Travel to places of work:

2011 Census: "Method of travel to work England and Wales, 2011. Employed usual residents aged 16 to 74, plus passengers, is 62.6%" This equates to approximately an extra 2200 car movements from BA1 morning and evening.

So how is this traffic expected to get in and out of BA1? The plan envisages a single 'distributor road' with two exits, one to North Road, and the other over a new bridge over the railway to the A505 junction.

Going into Baldock: Whether you leave BA1 by either exit this traffic must cross the lights at the The A507/B656 Junction.

"The junction is operating close to the degree of overload where queuing could be an issue. With no land available to modify the existing arrangement to increase the capacity, it would indicate that any notable future developments would require new or amended junctions/ roads elsewhere in the local network to accommodate the additional traffic generated by them." [Feasibility report (Nov 2014)]

The "junction is currently running close to capacity and will be unable to accommodate additional development flows with its current configuration. ... Additional mitigation measures would therefore be required at this location which have not been identified or costed for." (comment letter from Paul Donovan HCC Spatial Planning and the Economy Environment Department 3 Feb 15)

Our empirical experience of taking children to the Station every morning and evening backs this up; North Rd can often be stationary back to Norton Mill Lane from where it takes more than 15 Min to get to the traffic lights. Indeed it is nearly as congested as when this was the Great North Road before the A1(M) was built in 1966, when traffic would occasionally back up as far as Radwell Lane.

Going into Letchworth or A1(M) south via Letchworth Gate:

This is no better: "Key current congestion issues in the town include the area around Letchworth Gate and the A505 / A6141 junction" (comment letter from Paul Donovan HCC Spatial Planning and the Economy Environment Department 3 Feb 15)

NHDC's own information indicates the only reasonably uncongested routes out of BA1 are likely to be the A505 to Royston or North Road to J10 of the A1(M).

Travel to shopping:

The plan envisages "A new local centre along with additional neighbourhood-level provision providing around 500m2 (net) class A1 convenience retail provision and 1,400m2 (net) of other A-class floorspace" [Policy SP14 b] but this total provision for a proposed population of c.6500 people is barely 1/3 of the size of just one existing shop in Baldock. Tesco has a Net Sales floor space of 6,340 m2 [NHDC Appendix A Study Area and Existing Retail Facilities] and is already operating somewhere near its capacity at peak times.

All the nearby shops are either in the town centre, or Tesco, or are in Letchworth (Sainsburys, Lidl Etc) and to get to them all you must go through the junctions highlighted as either 'congested' or 'close to capacity' already.

It is certain that BA1 will cause such gridlock at the A507/B656 junction as to make access to Baldock from the surrounding villages to the North difficult or at times impossible. NHDC / HCC evidence states there is very little scope to improve it thus suggesting NHDC prefers BA1 residents to work and shop in Royston or Biggleswade. This is not a 'sustainable' solution.

"The River Ivel catchment is a fast responding catchment meaning it is vulnerable to flash flooding following a significant rainfall event." (Central Beds report CB/FLO/15/09003)

Currently (and for the last 60 years since my family have lived here) Radwell has NOT suffered from flooding, but in wet winters sometimes it does come close to it.

The proposed developments in Baldock plan to add c. 3200 new homes, all of which are in the River Ivel catchment. This infers the development is likely to significantly affect Radwell through increased water flows both from runoff and sewage treatment outfall.

Apparently no Surface Water Management Plan (SWMP) study has been conducted despite the fact that the proposal is to nearly double the size of the Baldock urban area which by any measure must represent a massive increase in flood risk to areas downstream of the catchment.

River flow at Radwell Mill has been measured to vary between 3.5 and 16 Megalitres(Ml)/day (oct 2015 - oct 2016, Affinity Water study).

Treated water:
In the absence of any alternative proposals, it is reasonable to assume the treated water from the developments will go into the River Ivel. On the basis of 2.3 persons per houshold (2011 census), annual water consumption of 110 m3 per houshold/annum (consumer council for water) and 3200 new households this represents an increased output of treated water into the Ivel of some 352 Ml per annum, increasing flow by between 6% and 27%.

Runoff:
"Developing a green field site may result in 10 times the runoff during extreme rainfall" (Woods-Ballard et al 2007). The plan mentions "Sustainable Drainage Systems (SuDS) and other appropriate measures" but these are in large part merely a 'buffer' of limited capacity and not capable of restricting flow for extended periods of wet weather when the river Ivel is already close to capacity. It is therefore easy to envisage that a development of this size is highly likely to lead to flooding in Radwell and other villages (eg Stotfold) downstream. This happened as recently as July 2015 and again in June 2016 when extreme rain events in Letchworth (c. 25mm in 90 minutes) overwhelmed Pix Brook and flooded houses in Stotfold.

25mm (c. 1 inch) of rainfall over 91 Ha is 22 Ml of water. The 5% runoff expected from the green field site would be 1.1 Ml, the runoff from the same area as residential development could be expected to be between 30% (6.8 Ml) and 60% (13 Ml) representing a potential increase of between 5.5 and 12.5 Ml of runoff in a single event, this will increase flow by between 78% and 157% representing a very serious risk of flooding.

Pollution:
Radwell lake is already deemed an area of "Wildlife and Nature policy 14" and we work hard to keep it nice. The massively increased runoff is likely to increase temperatures in our river, harming fish and other organisms; A sudden burst of runoff from a rainstorm can cause a fish-killing shock of hot water. Salt used to melt ice and snow on pavements and roads in the new developments will further contaminate our river.

Oil and other hard-to-monitor pollutants will get into our river from the newly developed areas. This already happened when the SuDS ponds associated with runoff from the A1(M) built in 1966 silted up after only 25 years of service and we began to see an occasional oil film (on one occasion a large quantity of it) polluting our river. Eventually the ponds were dredged at considerable expense because the silt was classified as hazardous waste.

LA1 is proposed on Green Belt Land described as 'North Baldock Chalk Uplands' charactized by its remote and open landscape.

"The reference to areas of remoteness is fully supported. The feeling of tranquillity is also a perceptual aspect of the landscape that should be protected wherever possible. Tranquillity provides relief from urban areas and benefits health and wellbeing, protecting any pockets of tranquillity is especially important in close proximity to highly developed areas." (comment letter from Paul Donovan HCC Spatial Planning and the Economy Environment Department 3 Feb 15)

In 1902 Ebenezer Howard wrote in Garden Cities of Tomorrow: "Shall it build on the zone of agricultural land which is around it and thus forever destroy its right to be called a 'Garden City'? Surely not." LG1 as farmland is of vital importance in maintaining the green belt design of the world's first garden city. To erode this beyond the natural skyline boundary of the existing built up area would be a critical loss to Letchworth's integrity and therefore no developer could possibly satisfy Policy SP15 condition a,i "How the site will follow and implement Garden City principles", Replacing green belt by some new areas near Luton airport is no mitigation.

It is also difficult to imagine how any development at a density of c.35 dwellings per Ha can possibly "implement Garden City principles" in any case.

This high density housing at LA1 will be especially deliterious to views from afar, eg from North Road between Radwell and Baldock and from the water tower at the junction of the A1 and the Langford Road where Letchworth is currently out of view in its own valley. It will become highly visible, and be a ruinous encroachment on the rural aspect of Letchworth from the North and especially to Radwell and its Wildlife area.

NPPF and Government statements
The Planning Minister in March 2014 reaffirmed NPPF priorities saying "Unmet housing need is unlikely to outweigh harm to the green belt and other harm to constitute the very special circumstances justifying inappropriate development on a site within the Green Belt"

NPPF requires Councils to protect the green belt when preparing their Plans. Para 14 states that the extent to which assessed housing needs are met should reflect constraints such as Green Belt. Guidance 1 re-confirms this.

NPPF says "The Government attaches great importance to Green Belts. The fundamental aim of Green Belt policy is to prevent urban sprawl by keeping land permanently open; the essential characteristics of Green Belt are their openness and their permanence."

"The River Ivel catchment is a fast responding catchment meaning it is vulnerable to flash flooding following a significant rainfall event." (Central Beds report CB/FLO/15/09003)

Currently (and for the last 60 years since my family have lived here) Radwell has NOT suffered from flooding, but in wet winters it does come close to it.

The proposed developments in Letchworth plan to add c. 900 new homes, all of which are in the River Ivel catchment. This infers the development is likely to significantly affect Radwell and Stotfold through increased water flows both from runoff and sewage treatment outfall.

Apparently no Surface Water Management Plan (SWMP) study has been conducted despite the fact that Flooding regularly occurs in Stotfold. This happened as recently as July 2015 and again in June 2016 when extreme rain events in Letchworth (c. 25mm in 90 minutes) overwhelmed Pix Brook and flooded houses in Stotfold.

River flow at Radwell Mill has been measured to vary between 3.5 and 16 Megalitres(Ml)/day (oct 2015 - oct 2016, Affinity Water study).

Treated water:
In the absence of any alternative proposals, it is reasonable to assume the treated water from the development will be pumped over the hill to Letchworth sewage plant thereby exacerbating the existing flooding issues with Pix Brook in Stotfold.

Runoff:
"Developing a green field site may result in 10 times the runoff during extreme rainfall" (Woods-Ballard et al 2007). The policy mentions "Incorporate ordinary watercourses (and any appropriate measures) within comprehensive green infrastructure and / or SUDs approach" In this development the fall of the land is towards the Ivel at Radwell where we already have flooding issues from the land between the Norton Road and the Grange Estate. (The land drains were relaid in 2013 which resulted in the Norton Road being flooded and the ditch on the Radwell side of the Norton Road overflowing.) It is therefore easy to envisage that a development of this size is highly likely to lead to flooding in Radwell and other settlements (eg Stotfold) downstream.

25mm (c. 1 inch) of rainfall over 40 Ha is 10 Ml of water. The 5% runoff expected from the green field site would be 0.5 Ml, the runoff from the same area as residential development could be expected to be between 30% (3 Ml) and 60% (6Ml) representing a potential increase of between 2.5 Ml and 5.5 Ml of runoff in a single event. Besides increasing the flow in the Ivel by between 30% and 80% the existing ditches into the Ivel cannot possibly be expected to cope with this sort of increase in flow so flooding is to be expected.

Pollution:
Radwell lake is already deemed an area of "Wildlife and Nature policy 14" and we work hard to keep it nice. The massively increased runoff is likely to increase temperatures in our river, harming fish and other organisms; A sudden burst of runoff from a rainstorm can cause a fish-killing shock of hot water. Salt used to melt ice and snow on pavements and roads in the new developments will further contaminate our river.

Oil and other hard-to-monitor pollutants will get into our river from the newly developed areas. This already happened when the SuDS ponds associated with runoff from the A1(M) built in 1966 silted up after only 25 years of service and we began to see an occasional oil film (on one occasion a large quantity of it) polluting our river. Eventually the ponds were dredged at considerable expense because the silt was classified as hazardous waste.

"The River Ivel catchment is a fast responding catchment meaning it is vulnerable to flash flooding following a significant rainfall event." (Central Beds report CB/FLO/15/09003)

Currently (and for the last 60 years since my family have lived here) Radwell has NOT suffered from flooding, but in wet winters sometimes it does come close to it.

The proposed developments in Baldock plan to add c. 3200 new homes, all of which are in the River Ivel catchment. This infers the development is likely to significantly affect Radwell through increased water flows both from runoff and sewage treatment outfall.

Apparently no Surface Water Management Plan (SWMP) study has been conducted despite the fact that the proposal is to nearly double the size of the Baldock urban area which by any measure must represent a massive increase in flood risk to areas downstream of the catchment.

River flow at Radwell Mill has been measured to vary between 3.5 and 16 Megalitres(Ml)/day (oct 2015 - oct 2016, Affinity Water study).

Treated water:
In the absence of any alternative proposals, it is reasonable to assume the treated water from the developments will go into the River Ivel. On the basis of 2.3 persons per houshold (2011 census), annual water consumption of 110 m3 per houshold/annum (consumer council for water) and 3200 new households this represents an increased output of treated water into the Ivel of some 352 Ml per annum, increasing flow by between 6% and 27%.

Runoff:
"Developing a green field site may result in 10 times the runoff during extreme rainfall" (Woods-Ballard et al 2007). The plan mentions "Sustainable Drainage Systems (SuDS) and other appropriate measures" but these are in large part merely a 'buffer' of limited capacity and not capable of restricting flow for extended periods of wet weather when the river Ivel is already close to capacity. It is therefore easy to envisage that a development of this size is highly likely to lead to flooding in Radwell and other villages (eg Stotfold) downstream. This happened as recently as July 2015 and again in June 2016 when extreme rain events in Letchworth (c. 25mm in 90 minutes) overwhelmed Pix Brook and flooded houses in Stotfold.

25mm (c. 1 inch) of rainfall over 91 Ha is 22 Ml of water. The 5% runoff expected from the green field site would be 1.1 Ml, the runoff from the same area as residential development could be expected to be between 30% (6.8 Ml) and 60% (13 Ml) representing a potential increase of between 5.5 and 12.5 Ml of runoff in a single event, this will increase flow by between 78% and 157% representing a very serious risk of flooding.

Pollution:
Radwell lake is already deemed an area of "Wildlife and Nature policy 14" and we work hard to keep it nice. The massively increased runoff is likely to increase temperatures in our river, harming fish and other organisms; A sudden burst of runoff from a rainstorm can cause a fish-killing shock of hot water. Salt used to melt ice and snow on pavements and roads in the new developments will further contaminate our river.

Oil and other hard-to-monitor pollutants will get into our river from the newly developed areas. This already happened when the SuDS ponds associated with runoff from the A1(M) built in 1966 silted up after only 25 years of service and we began to see an occasional oil film (on one occasion a large quantity of it) polluting our river. Eventually the ponds were dredged at considerable expense because the silt was classified as hazardous waste.