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Data Products and Interpolation

Oak Ridges Moraine Groundwater Program

The Oak Ridges Moraine Groundwater Program (ORMGP) maintains an authoritative understanding of:

  1. the geological layering for the area;
  2. the groundwater flow system; and
  3. linkages to the region’s surface waters and climatologies.

The ORMGP has the need to:

The following is an index to the data maintained and produced by the ORMGP. All data can be cited by a link below.


Data Warehousing

The ORMGP Database (MSSQL)

Our main MSSQL Server database holds all the information to support our decision-making tools. The ORMGP data systems are active, in that they are automatically updated at near real-time. From hourly and daily intervals, a series of web-scraping routines have been written to access open data made available from many sources including international, federal, provincial, municipal and conservation authority agencies. The objective is to centralize hydrogeological and hydrological data for the south-central Ontario (Canada) jurisdiction that currently makes-up the ORMGP.

Data source references.


The Delft-FEWS platform offers a streamlined user interface that allows practitioners to visualize time-varying spatially-distributed data from a variety of sources and formats. For instance, spatial/vector/raster time-series datasets common to climatology differ from the point/location datasets contained in the SQL database. We maintain a Delft-FEWS platform to manage these data formats. Our ORMGP-FEWS system periodically ($\leq$ 1 day) scrapes data from federal, provincial, municipal and partner agencies to support a variety of APIs serving near-real-time historical climatologies to our partner users.

More information:

  1. About the Delft-FEWS product by Deltares.
  2. More information on ORMGP web data scraping.

Data Sources


Description of the geological layers, their interpreted depositional setting, and of the procedures used to interpolate the surfaces.


Monitoring locations with >35 monitoring dates

Elevation, Drainage and Topology

For groundwater elevations, digital elevation data are used to correct depths of measure to metres above sea level (masl). Therefore, vertical accuracy and datum are tied to the digital elevation (terrain) model (DEM) we used as reference. Currently, correction are taken to the 10m 2006 OMNR Digital Elevation Model - Version 2.0.0 - Provincial Tiled Dataset.

Overland flow drainage and their pathways (topology) are defined using the 30m Provincial Digital Elevation Model - South (CGVD2013).

Sub-watershed characterization and flow topology

Hydro-meteorological station data

see interpolated data below

Web Applications

Geocortex Data Portal

The ORMGP Geocortex Mapping hub has been divided into various Theme Maps to allow users to quickly hone in on the information they might be seeking. For example, the Documents Theme Map provides access to the program’s library of reports, The Boreholes Theme Map focuses on providing access to borehole specific information, and the Geology Theme Map provides access to all of the ORMGP geologically related mapping. The Theme Maps group specific related data sets or interpreted products (more info here).

Our current web-mapping system relies on Geocortex

Geological layers

The geological layers made available on the Geocortex portal are found in two places: the Geology Theme Map and the cross-section tool. More information on their interpreted depositional setting and of the procedures used to interpolate the surfaces.

In the Geology Theme Map, users can view either the tops of or the isopach/thickness of any of the layers. The Geological Picks made at each well, that are used to construct or interpolate each layer are also available. A screen capture from the website showing the Top of Halton Till as well as the picks is shown below.

Cross-section tool

The cross-section tool is designed to provide a cut, along a user-defined line, through the subsurface to display the regionally interpreted Quaternary geological layers down to the bedrock.

Included in the Cross-section tool (in addition to hydrostratigraphy):

Piper plots

The piper plot tool presents water chemistry in an informative way and can be sorted by location or geologic formation.

Shiny Hydrology (sHydrology)

R-Shiny-Leaflet mapping with access to our monitoring dataset. Go to online map.

Time-Series Analysis

Open Data Products


Our metadata repository, Table of Contents.


Geospatial Layers

Static 2D fields as hosted on the ORMGP image server, updated frequently


Geological Surfaces (2021)

The geology layers presented on the ORMGP Website have been created at different times, and in cases, by different parties over the years. ORMGP staff are regularly checking the geological layers, making adjustments over time. However, these incremental changes are only periodically updated onto the website. The Figure below shows the various sets of geological layers that have been built into a regional picture and that are currently reflected on the ORMGP website.

more info

Water Table Mapping

The Oak Ridges Moraine Groundwater Program (ORMGP) has been working on producing a reliable water table map for quite some time. Over the years several versions of the water table surface have been prepared as new information has become available or as the technical mapping methodology has been adjusted. Although it sounds straightforward to interpolate a water table surface, there are a number of factors that make the process difficult. Here we outline some of the considerations that have gone into creating the water table surfaces (and their derivatives) and can serve as a supplementary document for those that make use of these layers. For more information, see the Fact Sheet.

Land use

The source of the land use data is: Ministry of Natural Resources and Forestry, 2019. Southern Ontario Land Resource Information System (SOLRIS) Version 3.0: Data Specifications. Science and Research Branch, April 2019.

From this layer, the follow land use categorizations are derived:

more info

Surficial Geology

The source of the land use data is: Ontario Geological Survey 2010. Surficial geology of southern Ontario; Ontario Geological Survey, Miscellaneous Release— Data 128 – Revised. From this layer, approximations of percolation rates that affect recharge rates.

more info

Clip ‘n Ship
Source: ArcMAP Clip function.

Spatially interpolated, near real-time data

Distributed time-series data, updated nightly

Numerical Modelling

Numerical modelling are applied in two ways:

  1. A long-term data assimilation system that uses hydrological analysis tools (i.e., models) and leverages the ORMGP’s database. What amounts to data assimilation system (DAS) utilized modelling technology to provide real-time interpolation of the hydrological system, data we have access to. The computational structure of the DAS is specifically tailored to run as fast as possible, such that thousands of model “projections” made continuously on ORMGP servers. The results from this analysis will likely be offered as monthly ranges in long term seasonal water balance estimates.
  2. Other tools are intended for predictive use, but are restricted to short-term (less than 30 days) projections. The design of these models is more physically rigorous but will always be dependent on other models (existing groundwater models or the DAS described here) to prescribe the antecedent conditions. While computational time for this model is orders of magnitudes greater than that of the DAS, it continuous to share the philosophy of designed whereby computation efficiency is paramount.

Combined, these two tools will provide all water groundwater resources needs for the ORMGP partners in order to:

  1. utilize readily available datasets provided daily by government agencies of Canada and the United States without the need for data pre-processing
  2. capture long-term hydrological water budget estimates with an emphasis on its certainty
  3. project near-term hydrological response given a known antecedent state

Existing numerical model files, output and sharing

We have established a numerical modelling sharing process to assist consultants in moving forward on various projects by making use of previous interpretations/work. The mission of the ORMGP numerical model custodianship program is to provide numerical models to any consultant undertaking work within our partners’ jurisdiction.

Users (e.g., consultants) are expected to review the shared models’ suitability to their intended application. Considering the age of the models, the expertise who constructed the model, the model’s original intent, etc., it is the responsibility of the user to determine whether there is an approach more suitable than just using the model files as delivered. For instants, some consultants have only selected specific model file components (i.e. hydraulic conductivity distribution or geological layering, thicknesses etc.) to complete their task.

Users are free to update/modify the model in the hopes that the refinements are shared in return and knowledge preserved.

Often, within any geographical area of a new/proposed consulting project, there are several models that could be used to aid the new project. Given the nature of the proposed project (e.g. water supply, contamination investigation, proposed land development, etc.) we could make suggestions the most appropriate model or the consultant is free to select any or all models, where available.

The idea is that model sharing could perhaps reduce duplication of effort, thereby lowering consulting costs by providing previous modelling insights in a transferable digital format. Given that every project is different, the likelihood that a model can be transferred to address the needs of a another study may be quite low.

Set of numerical models maintained in the custodianship program

Particle Tracking web-tool

The ORMGP particle tracking tool shows both the forward or backward particle tracking from a site that is being studied. The tool is built upon numerical models which have organized, synthesized and interpreted a wealth of hydrogeological information (e.g., boreholes, geological mapping, previous studies, etc.).

Regional Water Budget, Long-term and Continuous

Short-term/event-based hydrology



A number of open-source and proprietary data analysis tools have been employed in our overall data management system. In contribution to the open-source community, much of our work has also left open on our Github.

ORMGP Servers

Databases and REST-APIs

Web Scraping


click here