Richmond Hill is one of the few municipalities that publishes its own hydrogeological requirements in two versions, minor and major, through its Infrastructure and Engineering Services Department. A hydrogeological study in Richmond Hill follows one of those checklists, and in the south of the city it may also have to follow the groundwater recommendations of the City's Urban Master Environmental Servicing Plan.
What this means for your project in Richmond Hill
- Most Richmond Hill studies support infill and intensification with underground parking, site alteration, or subdivisions in the north of the city on the Oak Ridges Moraine.
- The City sets the report contents through its minor or major hydrogeological requirements. York Region approves dewatering discharge after the City, and Toronto and Region Conservation Authority reviews effects on natural features.
- A major study asks for much more than a minor one: regional geology, recharge areas, a water balance and permanent dewatering. Confirm which applies before you collect quotes.
- The local factor most likely to affect scope and cost: the Oak Ridges Moraine, which covers about half the city and can add a hydrological evaluation or water budget to the groundwater work.
Richmond Hill groundwater data
Calculated from public provincial datasets for City of Richmond Hill. Each value names its source; links are under Sources at the end of the page.
| Median depth of wells with a water level | 34.1 m (1,561 records reporting depth and water level) |
|---|---|
| Median static water level | 12.8 m below ground (1,561 records reporting depth and water level) |
| Records reaching bedrock | 1.5% of all records with a depth |
| Well records | 5,822 records (all types) |
| Active Permits to Take Water | 15 permits; largest purpose categories: Commercial 5, Dewatering Construction 4, Dewatering 3 |
| Active construction and dewatering permits | 9 of 15 active Permits to Take Water |
| Conservation authority | Toronto and Region Conservation Authority (99.8% of area) |
| Provincial plan areas | Oak Ridges Moraine 52.2%; Greenbelt 53.9% of area |
| Sewer discharge | Dewatering discharge needs City approval first, then a York Region approval under Sewer Use Bylaw 2021-102 (York Region) |
Source: Well Records (Water Well Information System), MECP (WWIS_2026a), retrieved 2026-10-14.
Source: Permit to Take Water, MECP (PermitsToTakeWater_26-01), retrieved 2026-10-14.
Source: Conservation Authority Administrative Area, Ontario GeoHub, retrieved 2026-10-14.
Source: Oak Ridges Moraine (ORM) Planning Area, Ontario GeoHub; Greenbelt Outer Boundary, Ontario GeoHub; Niagara Escarpment Plan Boundary, Ontario GeoHub; retrieved 2026-10-14.
Figures count records inside the municipal boundary that report a value; well locations and values are as submitted by well contractors, and MECP notes inaccuracies exist. How these figures are calculated.
9 of the 15 active Permits to Take Water in Richmond Hill are for construction or dewatering, and nearly all permitted sources draw groundwater. The median static water level in the city's well records is 12.8 m below ground, but on the moraine and in the valleys conditions change over short distances, which is why both City checklists ask for four seasons of monitoring.
The City's two hydrogeological checklists
Richmond Hill's minor and major hydrogeological study requirements are published with the City's site alteration permit guidelines. Both require a report stamped by a licensed professional geoscientist or exempted engineer, a study area covering the largest possible zone of influence of the groundwater taking or contaminant source, and the results of a water well records search. The differences are where the cost goes:
| Item | Minor | Major |
|---|---|---|
| Geology | Local geology and hydrogeology | Regional and local |
| Ecologically significant recharge areas | Not listed | Required |
| Water balance | Not listed | For sites where source protection plans require it, and pre- and post-development with and without mitigation |
| Dewatering assessed | Temporary | Temporary and permanent |
| Mitigation | Groundwater quality, temporary dewatering, settlement monitoring, volume monitoring | Adds recharge mitigation, a groundwater quantity monitoring program for discharge evaluation, reducing permanent dewatering and contingency plans |
| Urban MESP | Not listed | Conformance with sub-section 3.3.7 for sites in the study area |
Both versions also list private well surveys where needed, single-well response tests for formations that dewatering will affect, settlement assessment of existing structures, infiltration testing where low impact development is proposed, and a follow-up report confirming the affected zone has recovered if mitigation is recommended.
The Urban MESP groundwater recommendations
The major checklist names one local document. Sites inside the Richmond Hill Urban Master Environmental Servicing Plan study area have to be completed in conformance with the recommendations in sub-section 3.3.7 of its section on groundwater and subsurface conditions (May 2014). The City provides the MESP on request, so ask for it during pre-consultation and give it to your consultant before the scope is set. A study written without it can be returned.
How York Region fits in
The City's checklists closely follow York Region's shared terms of reference, which all York municipalities use with local additions; our Vaughan page explains the regional terms in full. For dewatering, Richmond Hill is a secondary approval municipality under York Region's sewer use bylaw: the City approves discharge first and the Region follows. York Region also issues source water protection permits for some proposals in wellhead protection areas.
The Oak Ridges Moraine in Richmond Hill
In the provincial boundary data, 52.2% of Richmond Hill is in the Oak Ridges Moraine planning area and 53.9% is inside the Greenbelt outer boundary. Under the Oak Ridges Moraine Conservation Plan (O. Reg. 140/02), development or site alteration near a key hydrologic feature needs a hydrological evaluation, and some major development needs a water budget and conservation plan. These sit alongside the City's major checklist, which already asks for recharge areas and a water balance, so one field program can usually serve both.
Hydrogeological study cost in Richmond Hill
| Study | Starting point | Full span |
|---|---|---|
| Hydrogeological report for a planning application | $12,000 – $18,000 | $12,000 – $150,000 |
| Excavation dewatering assessment | $9,000 – $14,000 | $9,000 – $62,500 |
| Pre- and post-development water balance | $3,000 – $5,000 | $3,000 – $14,000 |
| Sewer discharge and foundation drainage approvals | $3,500 – $6,000 | $3,500 – $15,500 |
These are indicative ranges based on typical scopes, the same province-wide ranges the estimator uses, not prices specific to Richmond Hill. Locally, the work is reviewed by the City of Richmond Hill, York Region and Toronto and Region Conservation Authority and, for water takings, the ministry, and the scope they ask for is what moves a quote. Whether the City's minor or major requirements apply, and the single-well response tests they ask for, set the field program. Excludes well drilling, government application fees and HST. Worked scenarios are in the cost guide for Ontario studies.
A sensible order of work in Richmond Hill
- At pre-consultation, ask which checklist applies (minor or major), whether the site is in the Urban MESP study area, and whether it is on the Oak Ridges Moraine or near a key hydrologic feature.
- Request the Urban MESP from the City if it applies, and give it to your consultant before the scope is priced.
- Install monitoring wells that can be used for single-well response tests, and start monitoring early: both checklists ask for four seasons.
- If construction will dewater, plan the City and York Region discharge approvals alongside the hydrogeological report, since the same water quality and volume data supports both.
Projects that need a hydrogeological study in Richmond Hill
- Intensification and infill with underground parking. Deeper excavations bring the major checklist, temporary dewatering and often a permanent dewatering assessment.
- Site alteration. Filling, grading or excavation under a City site alteration permit, whose guidelines include both hydrogeological checklists; ask the City which one applies.
- Moraine subdivisions. Water balance, recharge and hydrological evaluation near key hydrologic features.
- Low impact development. Infiltration testing where infiltration features are proposed.
Working with a hydrogeologist in Richmond Hill
Richmond Hill publishes two versions of its hydrogeological study requirements, minor and major, so the first question for City staff is which one applies to your site. Both ask for single-well response tests in the formations dewatering will affect, which means monitoring wells built to be tested rather than open geotechnical holes. For dewatering, the City reviews and approves the discharge first and York Region follows. Send the consultant the proposed footprint and underground depth so the hydrogeological assessment in Richmond Hill is scoped against the right checklist. Check the geoscientist on a Richmond Hill proposal through the PGO member search, or an engineer through the Professional Engineers Ontario licence search.
Where Richmond Hill dewatering needs provincial registration, our step-by-step guide to EASR dewatering registration covers it.
Richmond Hill questions
What is the difference between Richmond Hill's minor and major hydrogeological requirements?
Both come from the City's Infrastructure and Engineering Services Department and share the same core: a licensed author, a study area covering the largest possible zone of influence, monitoring wells, single-well response tests and four-season monitoring. The major version of the City's requirements adds regional geology, ecologically significant recharge areas, water balance (including pre- and post-development, with and without mitigation), permanent dewatering and the Urban MESP recommendations.
What is the Urban MESP, and does it apply to my site?
The Richmond Hill Urban Master Environmental Servicing Plan (May 2014) has a section on groundwater and subsurface conditions. The City's major guidelines say sites inside the Urban MESP study area must follow the recommendations in its sub-section 3.3.7, and that the City provides a copy on request. Ask the City whether your site is in the study area at pre-consultation.
Do I need a single-well response test, or will borehole data do?
Both City guideline versions list single-well response tests for the formations that dewatering will affect, and the results of that analysis among the supporting information. If the project dewaters, plan for monitoring wells that can be tested, not only geotechnical boreholes.
Who approves dewatering discharge from a Richmond Hill site?
Richmond Hill is one of the municipalities where York Region's dewatering approval is "secondary": the City reviews and approves the discharge first, and York Region issues its approval under Sewer Use Bylaw 2021-102 only after receiving the City's permit. The Region's sewer use page says its review takes up to six weeks after a complete package.
About half of Richmond Hill is on the Oak Ridges Moraine. What does that add?
About 52.2% of the city's area is in the Oak Ridges Moraine planning area in the provincial boundary data. Near key hydrologic features, development or site alteration needs a hydrological evaluation under the Oak Ridges Moraine Conservation Plan, and some major development needs a water budget and conservation plan. Our page on Caledon and the moraine sets out those rules.
If the development changes after the report is accepted, do we need a new study?
Not always a new study, but the City expects the report to keep up: its guidelines say a revised proposal needs an updated report, or a letter from the author explaining the changes and whether the conclusions still hold.
Studies for Richmond Hill sites
- Development Hydrogeological Study
Groundwater assessments that support subdivision, site plan and zoning applications.
- Construction Dewatering Assessment
Groundwater inflow estimates and dewatering rates for excavations, basements and servicing trenches.
- Water Balance Assessment
Pre- and post-development water budgets for planning approvals and low impact development design.
- Groundwater Discharge Permits & Foundation Drainage
Approvals for discharging pumped groundwater to municipal sewers, during construction and over the long term.
- Hydrogeological study cost guide
Ranges for every study type, side by side.
Near Richmond Hill
Sources
- Sewer Use Permits: Temporary Dewatering Discharge Program (Sewer Use Bylaw No. 2021-102) (opens in a new tab), York Region.
- Well Records: Water Well Information System (WWIS_2026a) and county Well Record Data Reports (WW_Reports_2026a) (opens in a new tab), Government of Ontario (MECP), Ontario Data Catalogue.
- Permit to Take Water dataset (PermitsToTakeWater_26-01) (opens in a new tab), Government of Ontario (MECP), Ontario Data Catalogue.
- Conservation Authority Administrative Area (opens in a new tab), Ontario GeoHub.
- Oak Ridges Moraine (ORM) Planning Area (opens in a new tab), Ontario GeoHub.
- Greenbelt Outer Boundary (opens in a new tab), Ontario GeoHub.
- Niagara Escarpment Plan Boundary (opens in a new tab), Ontario GeoHub.
- Hydrogeological Study Requirements (minor), site alteration permit guidelines (opens in a new tab), City of Richmond Hill, Infrastructure and Engineering Services.
- Hydrogeological Study Requirements (major), site alteration permit guidelines (opens in a new tab), City of Richmond Hill, Infrastructure and Engineering Services.
- Terms of Reference: Hydrogeological Report (Development Application Supporting Studies, June 2024) (opens in a new tab), York Region.
- O. Reg. 140/02: Oak Ridges Moraine Conservation Plan (opens in a new tab), Government of Ontario (e-Laws).
- Public Register (registered members) (opens in a new tab), Professional Geoscientists Ontario.
- Search for licence holders and engineering interns (opens in a new tab), Professional Engineers Ontario.
- Municipal Boundary - Lower and Single Tier (opens in a new tab), Ontario GeoHub.
- OHN Waterbody, 2M generalized layer (provincial hydrography dataset) (opens in a new tab), Ontario GeoHub.