Three Rivers
East of England · England · E0700010293,772 people at the 2021 Census. The White British majority here is projected to end around 2038. This profile combines observed Census data with clearly labelled modelled projections. Read the methodology and limitations or inspect the official sources.
Three Rivers had 93,772 residents at the 2021 Census, up 7.4% from 87,317 in 2011. The three largest ethnic groups were White British (68.0%), Asian (15.2%) and White Other (9.2%). This site's Hamilton-Perry model (version 8.0, projected from the 2011 and 2021 Censuses, held within the ONS 2022-based subnational population projections) puts the three largest groups in 2051 at White British (36.1%), Asian (31.6%) and White Other (12.5%).
Looking at a street rather than the whole area? Look up your postcode for the local authority and constituency it sits in.
Projected Falls below half around 2038
63,706 of Three Rivers’s 93,772 residents identified as White British at the 2021 Census. The projection takes that share from 68.0% to 36.1% by 2051. Interpolated between projection decades, so the year is approximate.
Three Rivers and the councils that border it, on the map
Three Rivers's estimated population rose 9.3% between mid-2011 and mid-2025, from 87,921 to 96,068 (ONS mid-year estimates, table MYE4). Its White British share fell 11.7 points between the 2011 and 2021 Censuses, from 79.7% to 68.0% (ONS Census 2011 table KS201EW, Census 2021 table TS021).
Population of Three Rivers, 2011 to 2025
| Council | Mid-2011 | Mid-2025 | Change |
|---|---|---|---|
| Buckinghamshire | 506,550 | 584,296 | +15.3% |
| Dacorum | 145,298 | 162,316 | +11.7% |
| Harrow | 240,499 | 272,612 | +13.4% |
| Hertsmere | 100,379 | 110,242 | +9.8% |
| Hillingdon | 275,499 | 326,671 | +18.6% |
| St Albans | 141,248 | 150,757 | +6.7% |
| Three Rivers | 87,921 | 96,068 | +9.3% |
| Watford | 90,653 | 107,658 | +18.8% |
Change since mid-2011, every year
| Council | 2011 | 2012 | 2013 | 2014 | 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Buckinghamshire | 0.0% | +1.1% | +2.2% | +3.4% | +4.6% | +5.7% | +6.4% | +7.0% | +7.8% | +8.4% | +9.6% | +10.8% | +12.5% | +14.2% | +15.3% |
| Dacorum | 0.0% | +1.1% | +1.9% | +2.8% | +3.9% | +4.9% | +5.5% | +6.0% | +6.2% | +6.5% | +6.8% | +7.5% | +9.2% | +10.9% | +11.7% |
| Harrow | 0.0% | +1.4% | +2.7% | +4.6% | +6.2% | +7.0% | +7.2% | +8.1% | +9.0% | +9.1% | +8.6% | +9.4% | +11.4% | +12.7% | +13.4% |
| Hertsmere | 0.0% | +1.0% | +1.8% | +3.2% | +4.0% | +5.0% | +5.5% | +6.1% | +6.8% | +7.2% | +7.7% | +8.1% | +9.1% | +9.6% | +9.8% |
| Hillingdon | 0.0% | +2.1% | +3.8% | +5.3% | +6.7% | +8.0% | +8.7% | +9.7% | +10.9% | +11.2% | +10.7% | +13.4% | +17.0% | +19.0% | +18.6% |
| St Albans | 0.0% | +1.0% | +2.1% | +3.3% | +4.0% | +4.7% | +4.5% | +4.5% | +4.8% | +5.2% | +5.2% | +5.2% | +6.0% | +6.7% | +6.7% |
| Three Rivers | 0.0% | +1.4% | +2.2% | +3.2% | +4.6% | +5.7% | +5.9% | +6.0% | +6.3% | +6.7% | +6.8% | +7.2% | +8.1% | +8.7% | +9.3% |
| Watford | 0.0% | +2.7% | +5.6% | +8.2% | +9.7% | +10.8% | +11.4% | +12.1% | +12.7% | +12.9% | +13.1% | +13.8% | +16.1% | +17.8% | +18.8% |
Ethnic groups in Three Rivers, 2011 and 2021
The map shows the White British share. The bars show all six groups, on one scale, for each council in 2011 and 2021.
- White British
- White Other
- Asian
- Black
- Mixed
- Other
| Council | 2011 | 2021 | Change |
|---|---|---|---|
| Buckinghamshire | 81.1% | 72.6% | −8.5 pts |
| Dacorum | 86.0% | 78.7% | −7.2 pts |
| Harrow | 30.9% | 20.5% | −10.4 pts |
| Hertsmere | 75.7% | 63.1% | −12.6 pts |
| Hillingdon | 52.2% | 37.1% | −15.1 pts |
| St Albans | 81.2% | 73.5% | −7.6 pts |
| Three Rivers | 79.7% | 68.0% | −11.7 pts |
| Watford | 61.9% | 45.8% | −16.1 pts |
All six groups, 2011 and 2021
| Council | Census | White British | White Other | Asian | Black | Mixed | Other |
|---|---|---|---|---|---|---|---|
| Buckinghamshire | 2011 | 81.1% | 5.3% | 8.6% | 2.1% | 2.5% | 0.5% |
| Buckinghamshire | 2021 | 72.6% | 7.3% | 12.3% | 2.6% | 3.5% | 1.6% |
| Dacorum | 2011 | 86.0% | 4.8% | 4.7% | 2.1% | 2.1% | 0.3% |
| Dacorum | 2021 | 78.7% | 8.1% | 5.8% | 2.8% | 3.4% | 1.2% |
| Harrow | 2011 | 30.9% | 11.4% | 42.6% | 8.2% | 4.0% | 3.0% |
| Harrow | 2021 | 20.5% | 15.9% | 45.2% | 7.3% | 3.8% | 7.2% |
| Hertsmere | 2011 | 75.7% | 9.3% | 7.4% | 3.9% | 2.6% | 1.0% |
| Hertsmere | 2021 | 63.1% | 14.0% | 10.5% | 4.8% | 3.7% | 3.9% |
| Hillingdon | 2011 | 52.2% | 8.4% | 25.3% | 7.3% | 3.8% | 3.0% |
| Hillingdon | 2021 | 37.1% | 11.1% | 33.3% | 7.8% | 4.4% | 6.3% |
| St Albans | 2011 | 81.2% | 7.3% | 6.4% | 1.7% | 2.8% | 0.7% |
| St Albans | 2021 | 73.5% | 10.1% | 8.2% | 2.1% | 4.3% | 1.8% |
| Three Rivers | 2011 | 79.7% | 6.6% | 9.2% | 1.8% | 2.3% | 0.5% |
| Three Rivers | 2021 | 68.0% | 9.2% | 15.2% | 2.4% | 3.6% | 1.7% |
| Watford | 2011 | 61.9% | 10.1% | 17.9% | 5.8% | 3.4% | 0.9% |
| Watford | 2021 | 45.8% | 15.1% | 24.5% | 6.3% | 4.8% | 3.6% |
Ethnic composition trajectory
Solid to 2021 is Census. Dashed after that is the model, which was scored against Census 2021 before publication: a mean absolute error of 1.56 percentage points on that one-decade forecast and a bias of +0.05 points, close to unbiased. The shaded band is the 80% interval for White British share.
Ethnic composition, Three Rivers
White British White Other Asian Black Mixed Other 80% interval
Census, observed Projected, modelled
Show the figures
| Year | White British | White Other | Asian | Black | Mixed | Other |
|---|---|---|---|---|---|---|
| 2011 | 79.7% | 6.6% | 9.2% | 1.8% | 2.3% | 0.5% |
| 2021 | 68.0% | 9.2% | 15.2% | 2.4% | 3.6% | 1.7% |
| 2031 modelled | 58.0% | 10.8% | 20.3% | 2.8% | 5.3% | 2.7% |
| 2041 modelled | 47.2% | 12.0% | 25.7% | 3.2% | 7.8% | 4.1% |
| 2051 modelled | 36.1% | 12.5% | 31.6% | 3.3% | 10.9% | 5.6% |
| 2061 modelled | 25.8% | 12.2% | 36.8% | 3.3% | 14.7% | 7.1% |
Ethnic composition: Three Rivers
Census 2011, Census 2021, then Hamilton-Perry projections to 2051. Percentages.
White British White Other Asian Black Mixed Other
Two-model comparison: White British, 2051
±4.6pp spread Hamilton-Perry (HP) central 36.1% Cohort change ratios from Census 2011 to 2021. Demographic momentum only, no fertility convergence.
Cohort-component 40.7% Births by ethnicity-specific total fertility rate (TFR) with half-convergence to the national mean by 2061. Slower change.
Two independent models trained on the same Census base disagree by 4.6pp on White British share in Three Rivers by 2051. HP captures observed 2011 to 2021 cohort dynamics. The cohort-component model adds explicit fertility assumptions that pull projections toward the national mean. The chart above shows HP. See the methodology for why both numbers are published.
Scenario explorer
Under different assumptions, White British share in Three Rivers ranges from 35.4% to 50.9% by 2051: a 15.5pp spread.
Fertility
Low ~108k/yr
Principal ~315k/yr
High ~476k/yr
Constant Rates stay at current levels
Half convergence Move halfway to national avg
Full convergence Converge to national avg
Migration
Central scenario: WBI 40.8% by 2051
Diversity index
diverse Shannon entropy: 0.58 · Dissimilarity: 8.6
Religion
Census 2021 religious composition with projections to 2051.
Religious composition trajectory
Christian No religion Muslim Hindu
Census, observed Projected, modelled
Show the figures
| Year | Christian | No religion | Muslim | Hindu |
|---|---|---|---|---|
| 2021 | 50.5% | 32.7% | 3.9% | 8.8% |
| 2031 modelled | 35.9% | 39.5% | 5.8% | 14.4% |
| 2041 modelled | 23.1% | 43.3% | 7.7% | 21.2% |
| 2051 modelled | 13.6% | 43.5% | 9.4% | 28.7% |
Country of birth
UK-born vs foreign-born share, with projection to 2051.
Nativity trajectory
UK-born Foreign-born
Census, observed Projected, modelled
Show the figures
| Year | UK-born | Foreign-born |
|---|---|---|
| 2021 | 81.0% | 19.0% |
| 2031 modelled | 68.1% | 31.9% |
| 2041 modelled | 51.6% | 48.4% |
| 2051 modelled | 34.8% | 65.2% |
English proficiency
Census 2021
Main language English92.3%
Main language not English7.7%
Cannot speak English well0.7%
Cannot speak English at all0.1%
Total population 3+90,746
ONS Census 2021 (TS029) via NOMIS. Reference date 21 March 2021.
Data flag 7.7% of residents aged 3 and over have a main language other than English (Census 2021, TS029), below the 15% line this site uses to flag language demand. A threshold on one Census variable, not a service-planning assessment. This site publishes no projection of language: it models ethnic group, and ethnic composition change is not a measure of language change.
Demographic change and service exposure
A composite score from five capped components. It measures exposure to demographic change, not service cost or capacity, and it has not been validated against observed service demand. See how the score is built.
Ethnic change20/20
Asylum0/20
School0/20
Language8/20
Housing20/20
New arrivals (NINo registrations)
Adults from overseas registering for a National Insurance number, rolling year ending Oct-25 to Dec-25. Three Rivers ranks at the 28th percentile nationally for total NINo registrations.
Registrations (rolling year)249
Year-on-year -14.4%
NationalityRegistrationsShare
India 78 31.3%
Nepal 22 8.8%
Australia 20 8.0%
Ukraine 18 7.2%
China 17 6.8%
United States 14 5.6%
Canada 14 5.6%
Pakistan 12 4.8%
France 11 4.4%
Sri Lanka 11 4.4%
DWP National Insurance number allocations to adult overseas nationals (Stat-Xplore NINO database), rolling year ending Q4 2025.. NINo registrations measure new arrivals into the National Insurance system, not total foreign-born population. A NINo is allocated when an overseas national requests one, usually to start work or claim benefits, so the figure misses students and dependants who never enter the labour market. Small (LA × nationality) cells are suppressed by Stat-Xplore for disclosure control.
Arrivals over the last 24 years
Annual NINo registrations to adults from overseas in Three Rivers from 2002 to 2025, alongside the UK total for context. The peak year was 2023 (652 registrations). Total over the full period: 7,131 registrations.
DWP Stat-Xplore, NINO Registrations to Adult Overseas Nationals Entering the UK (Ninos cube), aggregated per calendar year by summing the four constituent quarters. Geography: ONS LA codes. Counts are NEW NINo registrations per calendar year. A NINo is issued once per person at the point of first work or claim, so this is a flow measure, not a stock. People who arrive but never register (some students, dependants, retirees) are excluded. Late registrations show in a later year than the year of arrival. Pre-2010 figures used a different administrative system; series is comparable but small methodological revisions to the early years are possible.
Who is arriving
Age and sex profile of 303 NINo registrations to adults from overseas in Three Rivers in 2025. National comparison shown alongside.
Age at registration
Three Rivers UK marker
Sex
Male share is 14.1pp lower than the UK average (54.4%).
DWP Stat-Xplore Ninos cube, LA × Age band × Sex, rolling year ending Q4 2025 (January 2025 to December 2025). Counts are NEW NINo registrations to adult overseas nationals. Age is age at NINo registration, not age at arrival. The registration may follow arrival by months. 'Less than 18' is rare in this dataset because the published Ninos series is filtered to adult overseas nationals; values reflect young workers/claimants close to 18. 'Unknown' age is a small residual.
Why people are coming
For each of the top arriving nationalities in Three Rivers, this is the national mix of visa routes used in 2025. It shows whether arrivals from that country are typically students, workers, on family routes (including refugee family reunion), or in some other category. Local-authority breakdowns of visa routes are not published, so we apply the national mix at nationality level.
India 78 in Three Rivers (31.3%)
Nepal 22 in Three Rivers (8.8%)
Australia 20 in Three Rivers (8.0%)
Ukraine 18 in Three Rivers (7.2%)
China 17 in Three Rivers (6.8%)
Home Office, Immigration system statistics, year ending June 2026; Vis_D02 (Entry clearance visa outcomes by nationality, visa type, and outcome). Joined with DWP Stat-Xplore NINo registrations rolling year ending Q4 2025. Visa grants are issued at the point of entry-clearance application and are NOT the same population as NINo registrations. Visitor visas (2.24 million in 2025) do not lead to NINo and are excluded from the route-mix percentages so the Work / Study / Family / Other proportions are interpretable. Humanitarian routes (BN(O), Ukraine schemes, Resettlement, Asylum) are surfaced as national totals only because the same nationality split is not provided in this dataset. EU/EEA nationals largely fall outside entry-clearance for short stays, so their NINo flow is materially understated by visa data alone.
How Three Rivers changed: 2011 to 2021
Two snapshots from two consecutive Censuses, ten years apart. Population changed from 87,317 in 2011 to 93,773 in 2021 (+7.4%). Non-UK-born residents went from 12,100 (13.9% of population) to 17,820 (19.0%).
Group 2011 2021 Change
UK-born 75,217 86.1% 75,953 81% +736
Ireland-born 1,144 1.3% 995 1.1% -149
EU pre-2001 (France, Germany, Italy, etc.) 1,687 1.9% 2,063 2.2% +376
EU 2001-2011 accession (Poland, Romania, Bulgaria, etc.) 1,078 1.2% 2,818 3% +1,740
Rest of World 8,191 9.4% 11,944 12.7% +3,753
Source: ONS Census 2011 KS204EW (NOMIS NM_611_1) and Census 2021 TS012 (NOMIS NM_2032_1), aligned to broad country-of-birth groups. 2011 data uses 2011 LA boundaries; 2021 data uses 2023 boundaries. LAs whose ONS code changed between Censuses (Buckinghamshire, Northamptonshire, North Yorkshire, Somerset reorganisations) are not in this comparison.
Schools, first language
Across 42 state-funded schools in Three Rivers (18,542 pupils, 2025/26), 21.1% have a first language other than English. The published Hertfordshire-wide upper-tier figure is lower, 18.9%, because it averages every district in the county; this is the genuine Three Rivers number.
Pupils with first language other than English3,347 (21.1%)
Pupils with first language English12,414 (78.3%)
Free school meals10.5%
Source: DfE Schools, Pupils and their Characteristics 2025/26, school-level data aggregated to district. EAL (English as Additional Language) is a household-level signal: children born in the UK to non-English-speaking households count as EAL.
Crime
Police-recorded crime rates per 1,000 population, Year ending March 2026, ONS. Three Rivers ranks at the 17th percentile nationally for total crime rate.
Total crime / 1k52.2
Violent crime / 1k21.3
Theft / 1k17.3
Drug offences / 1k2.0
Year-on-year -1.4%
Police force: Hertfordshire. It could not place 1.4% of the offences it recorded in this period in any area, and those offences are in no area's figure.
ONS, Crime in England and Wales: Police Force Area data tables, year ending March 2026 (released 23 July 2026), Tables C1, C2 and C5, police recorded crime from the Home Office; rates per 1,000 residents on ONS mid-2025 population estimates. Police recorded crime is shaped by recording practice, reporting rates and policing priority, and city centre rates are inflated by small resident populations. Offences a force could not place in any area are left out of area figures; each area shows its force's unassigned share.
Adult social care
Adult social care for Three Rivers residents is delivered by Hertfordshire County Council. Figures below are the county-wide ASC profile.
Council spending on adult social care (2024-25) and residential care for people aged 65 and over (2024-25), against each age group's population in the ONS mid-2025 estimates. Spend per adult ranks at the 57th percentile nationally.
Gross spend per adult (18+), 2024-25£651
Aged 65+ in residential care per 10,000 aged 65+, 2024-25101
Department of Health and Social Care, Adult social care finance report, England: 2024 to 2025, Table 14; Department of Health and Social Care, Adult social care activity report, England: 2024 to 2025, Table 34; Office for National Statistics, Mid-Year Population Estimates, England and Wales, June 2025, for the per-head rates. Adult social care is run by upper tier councils (counties, unitaries, metropolitan districts and London boroughs), so a district shows its county's figures. Spend reflects age structure, deprivation and unpaid care, so differences between councils are not a measure of efficiency. Activity figures are official statistics in development.
Department of Health and Social Care change note on the activity report, 7 October 2026: “Added notice of planned corrections to the 2024 to 2025 activity report, affecting data submitted by some local authorities. Updated figures will be published alongside the 2025 to 2026 activity report.”
Health by ethnic group
Share reporting "not good health" in each of Three Rivers's largest ethnic groups, Census 2021.
White 15.4%
White: English 16.0%
Asian 9.2%
ONS Census 2021 (RM043 - General health by ethnic group by age) via NOMIS. All ages, no age-standardisation: younger ethnic-group populations will show lower rates partly because they're younger, not necessarily because they're healthier. Group labels shortened for display.
Special educational needs
SEND for Three Rivers pupils is administered by Hertfordshire County Council. Figures below are the county-wide EHCP profile.
EHCPs and primary need breakdown, 2025/26 academic year. 5-year EHCP growth ranks at the 86th percentile nationally.
Pupils with an EHC plan, % of pupils5.1%
Pupils with an EHC plan11,459
Autism, share of EHC plans29.1%
5-yr growth +89.0%
Autistic spectrum disorder 29.1%
Social, emotional and mental health 20.3%
Speech, language and communications needs 16.6%
Moderate learning difficulty 9.1%
Severe learning difficulty 7.6%
Specific learning difficulty 6.4%
DfE, Special educational needs in England, academic year 2025/26, published 11 June 2026, Explore Education Statistics: pupils in all schools by type of SEN provision, and pupils with an EHC plan by primary type of need. SEND is run by upper-tier councils, so district pages show their county. Figures count pupils on the January school census who have an EHC plan; plans held by children under school age, young people in further education and those not in school are not included. The autism figure is the share of pupils with an EHC plan whose primary need is autism, not a prevalence in the population. Rising numbers may reflect identification, diagnosis and parental awareness as well as need.
How NHS care for overseas residents is funded (national context)
Most non-UK residents in Three Rivers pay for NHS care up-front through the Immigration Health Surcharge (IHS), which is added to most visa applications. Asylum seekers, refugees, ILR holders and Irish citizens are exempt. Visitors and undocumented residents are charged at 150% of the national NHS tariff. The figures below are England + Wales national totals; per-LA NHS cost-recovery is not centrally published.
Current IHS rate (adult, per year) £1,035
IHS rate, students/under-18s (per year) £776
IHS revenue 2024/25 (£m) £1,315.6m
Cumulative IHS revenue 2015-2024 £6.9bn
IHS rate history
- From 2015-04-06: £200/year adult, £150/year students/under-18s
- From 2019-01-08: £400/year adult, £300/year students/under-18s
- From 2020-10-27: £624/year adult, £470/year students/under-18s
- From 2024-02-06: £1035/year adult, £776/year students/under-18s
Indicative charges for visitors and undocumented residents
Maternity care is classified as "immediately necessary": it cannot be refused or delayed for charging, but it is invoiced afterwards at 150% of the NHS national tariff.
- Routine vaginal delivery, no complications: £3,000-£5,500
- Caesarean section: £5,000-£7,500
- Premature birth with NICU stay: £15,000-£30,000+
- Antenatal appointment: £150-£400 each
Sources: NHS (Charges to Overseas Visitors) Regulations 2015 (as amended); Home Office IHS caseworker guidance (Sept 2025); House of Commons Library briefing CBP-7274; NHS England NHS Payment Scheme (national tariff). Approximately 80% of identified overseas-visitor debt across all NHS treatment is uncollected (NAO, follow-up scrutiny).
Economic profile
Avg employment rate54.2%
Avg home ownership58.6%
Avg social rent12.1%
Degree or above35.4%
No qualifications10.9%
Housing
Composition today
How dwellings in Three Rivers are occupied. Single-person households and houses in multiple occupation are the two cleanest signals.
Single-person discount take-up29.4%
Dwellings on 25% single-person discount11,237
HMO dwellings (Census 2021)31
HMOs per 1,000 population0.33
Sources: MHCLG Council Taxbase 2025 (CTB, snapshot 6 October 2025) for single-person discount; ONS Census 2021 RM192 for HMO dwellings. HMO Census numbers reflect dwellings classified as HMO on Census Day; current licensing registers held by individual councils are not centrally published.
Tenure by ethnic group
Household ownership rates for Three Rivers's largest ethnic groups, Census 2021.
White: owned 70.6%
White: English: owned 72.1%
Asian: owned 84.9%
ONS Census 2021 (RM134 - Tenure by ethnic group, Household Reference Persons) via NOMIS. Group labels shortened for display.
Tenure projection
Census 2021 tenure patterns by ethnicity, projected to 2041 from demographic composition change.
Ownership (2021)58.6%
Social rent (2021)12.1%
Private rent (2021)11.7%
Ownership (2041)49.2%
Social rent (2041)10.1%
Social rent change-2pp
Data flag The foreign-born share is projected to rise by 46.2pp between 2021 and 2051 (Census 2021 TS004 country of birth, projected by the Hamilton-Perry method), above the 15pp line this site uses to flag housing demand. A threshold on one projected variable, not a housing-need assessment.
Westminster constituencies
Parliamentary constituencies overlapping Three Rivers, largest first by the share of each constituency's postcodes that fall in Three Rivers.
Asylum and immigration data
Asylum seekers on support, hotel costs, grant rates, and the True Cost of Asylum for this area.
View Three Rivers on Asylum Stats →
Local geography The shared local-authority geography record and its source coverage. Place record on UK Places