WaterML 2.0 SWG

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WaterML 2.0 Standards Working Group

WaterML 2.0 Part 1 is an Open Geospatial Consortium encoding standard (opengeospatial.org/standards/waterml) for the representation of hydrological observations data, with a focus on time-series. Theis work activities defined in this charter extends WaterML 2.0 with the inclusion of WaterML2 Part 2 - Ratings, Gaugings and Sections.

WaterML 2.0 is implemented as an application schema of the Geography Markup Language version 3.2.1 and makes use of the OGC Observations and Measurements (O&M) standard and the OMXML GML Application Schema.
OGC WaterML 2.0 Part 2 will support encoding of hydrological reference data described as stream discharge ratings, stream gaugings and river cross sections in a variety of exchange scenarios.

Example areas of usage are: exchange of rating data for the calculation of derived values (e.g. enable the calculation of flow records from stream flow observations); exchange of  discrete river discharge flow measurements and river sections to enable quality assessment of rating tables.

Purpose of this Standards Working Group

The purpose of this Standards Working Group is to progress the candidate standard (OGC 13-021r3) of the Hydrology Domain Working Group to the state of an adopted OGC Standard. This goal will be achieved by conducting an Interoperability Experiment using the candidate standard, developing and publishing a draft standard, processing comments received during a public comment period and ensuring that the standard is consistent with the OGC Standards Baseline and Business Plan.

Scope of Work

This SWG is focused on the WaterML 2.0 Part 2 candidate standard submission (OGC 13-021r3), coordinating a public comment period, and processing any comments received during this period. The final deliverable of the SWG will be a version of the candidate standard for consideration by the OGC membership for approval as an OGC standard.

What is out of scope?

While OGC standard services, such as WFS and SOS, are the preferred mechanism for exchanging information, WaterML 2.0 does not specify a specific transport mechanism or service interface. Interoperability experiments led by members of the Hydrology DWG are testing compatibility of the draft WaterML2.0 part 2 with existing OGC services such as WFS and SOS as well as a RESTful API. Experiments are also testing approaches for alternate encodings to XML, such as JSON. Standariszation of the RESTful API and json encodings is out of scope.

This SWG will not address harmonizing or defining vocabularies sets, such as observable properties, for use with WaterML2.0 Part 2. The standard will define a number of URIs that will be used to convey the nature and state of observations, such as quality codes and data types with the aim of enhancing interoperability.

This SWG will focus only on processing comments received during the 30 day public comment period. Separately submitted Change Requests are out of scope, and will only be considered at the discretion of the SWG.

Specific Contribution of Existing Work as a Starting Point

The starting point for the work will be the draft WaterML 2.0 Part 2 submission (OGC 13-021r3). This will be sent out for public comment following any edits required to meet candidate standard requirements.

How it is to be Determined when the Work of the SWG has been Completed?

The work of the SWG will be complete when:

  • All comments submitted during the 30 day public comment period have been dealt with to the satisfaction of the SWG.

  • The SWG approves the WaterML 2.0 Candidate Standard and ATS document, for submission to the TC for approval as an adopted standard.

  • The candidate standard has been approved by the OGC Technical and Planning Committees as an Adopted OGC standard.

Description of deliverables

The following deliverables will result from the work of this SWG:
•    An annotated list of all comments submitted during the 30 day public comment period, including the comment, submitter, rationale, comment type/priority, and the response of the SWG.
•    A final version of the WaterML 2.0 Part 2 Standard and ATS documents for submission to the TC.
In recognition of the amount of effort from a number of groups that has gone into developing WaterML2.0 to its current state, the SWG should conclude its activities no later than Q4 2015. As such the following schedule of activities is planned:
•    SWG startup. 2014 August.
•    OAB/ONA RFC review; SWG prepares candidate standard for vote for public release. 2014  December
•    SWG votes to release WaterML 2.0 for public comment. 2015 January
•    OGC staff develops PR and announces availability for public comment. 2015 January
•    30-day public comment period. 2015 January  - 2015 February
•    SWG collects and collates comments into a single document. 2015 March
•    SWG discusses and votes on comments and makes resulting edits towards final WaterML 2.0 candidate standard. 2015 April
•    SWG votes to approve release of WaterML 2.0 candidate standard for approval as an OGC adopted standard. 2015 April
•    60 day IPR review period and associated TC e-vote to approve WaterML 2.0 candidate standard as an OGC adopted standard. 2015 April – 2015 June

IPR Policy for this SWG

RAND-Royalty Free.

Anticipated Participants

The target audience/participants of WaterML 2.0 includes: application developers; GIS and hydrologic software vendors; the hydrologic research and education community; international, national and local water-related agencies that set standards for, distribute and use hydrologic and hydrogeologic observation data; and the consumer.

Development of WaterML2.0 to date has been undertaken by the following OGC members:

a) Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO)
b) Australian Bureau of Meteorology (BoM)
d) Centre for Ecology & Hydrology (CEH) – United Kingdom
e) United States Geological Survey (USGS)
f) Aquatic Informatics

It is envisaged that these organization, at least, will participate in the SWG.

Other informative information about the work of this SWG

a. Similar or applicable standards work (OGC and elsewhere).

The following standards and projects may be relevant to the SWG's planned work, although none currently provide the functionality or domain focus anticipated by this committee's deliverables:
13-021r3 WaterML2.0 - part 2: Ratings, Gaugings and Sections
Discussion Paper
WaterML2.0 part 2 Interoperability Experiment Engineering report (to be published August 2014)
OGC Observations and Measurements 2.0, OGC AS Topic 20
(also ISO DIS 19156:2010)
OGC Geography Markup Language v3.2 (also ISO 19136:2007)
OGC Observations and Measurements XML (OMXML) Encoding Standard

The SWG intends to seek and if possible maintain liaison with each of the organizations maintaining the above works.

b. Details of the first meeting

The first meeting of the committee will be held at the August 2014 OGC Hydrology Domain Working Group  meeting in New York, USA. Call-in information will be provided to the SWG's e-mail list and on the portal calendar in advance of the meeting. The main items of business will be to select (co-)chair(s) for the SWG, and the primary editor for the standard, and agree on a schedule of work, including regular meetings if required.

c. Projected on-going meeting schedule

The work of the committee will be carried out primarily by email and conference calls, every other week, with face-to-face meetings at each of the OGC TC meetings. Other face to face meetings may be called if this can expedite the work of the SWG.

d. Supporters of the Proposal

The following people support this proposal and are committed to the Charter and projected meeting schedule. These members are known as SWG Founding or Charter members. Once the SWG is officially activated, this group is immediately “opted-into” the SWG and have voting rights from the first day the SWG is officially formed. Extend the table as necessary.

Peter Taylor


David Lemon


Tony Boston

Australian Bureau of Meteorology

Paul Sheahan

Australian Bureau of Meteorology

Michael Natschke


Peter Heweston


Matt Fry

Centre for Ecology & Hydrology

David Briar


Stuart Hamilton

Aquatic Informatics

Brian Gouge

Aquatic Informatics




IETF RFC 2616, Hypertext Transfer Protocol – HTTP/1.1. (June 1999)

ISO 8601:2004, Data elements and interchange formats — Information interchange —
Representation of dates and times.

ISO 19101:2002. Geographic information -- Reference model

ISO 19107:2003, Geographic Information — Spatial schema.

ISO 19111:—1), Geographic Information — Spatial referencing by coordinates.

OGC 07-136, OGC Geography Markup Language

OGC 10-004r3, OGC Observations and Measurements v2.0

OGC 00-014r1, Guidelines for Successful OGC Interface Specifications

OGC Document 08-095r5 - Hydrology Domain Working Group Charter, , 26th April 2008 updated 2 OGC Document 07-041r1 WaterML (OGC Discussion Paper)

OGC Document 10-126r1 WaterML2.0: An O&M Profile for Water Observation Data (OGC Implementation Profile)

OGC Document 09-124r2 - Harmonising Standards for Water Observation Data (OGC Discussion Paper)

WMO-168: Guide to Hydrological Practices, Sixth edition, 2008.