Public access to utilities system data


Thread Starter

David Collins

I am a reporter for a newspaper in New Mexico examining public access to public data held by a small public water utility. The software manufacturer tells me data is stored in POCs as likely Modbus data, and hence would be public data under our state's public records laws.

The software configuration in this system does not provide an easy means for porting a public view of well activity or tank levels separate from secure areas of the Web accessible SCADA system controls. Generally, the company that wrote developed the SCADA system has never been asked to develop a public view, and a sales rep says it could cost thousands to develop such access.

For the sake of discussion, let's presume the public has a right, need and desire to know how much water is in the system at any moment. Can anyone cite a system where public access to water system data has been provided in a SCADA system, or a circumstance where the concept has been considered and rejected?
Interesting idea, but I can imagine a utility operator being a bit suspicious of your motive, he would be worried about the headlines
I'm sure your local utility provide the information when you ask for it.
I have seen a display in visitors area that allows the public to scroll around the DCS screens

You are right though, if we own the utility why not. I don't think cost is the issue, security more likely.


Old, Bob (SBT US)

Whatever the format of the data, you seem to be asking for the same information that is needed by the water department in order to operate, troubleshoot, and plan for the water system's growth.

I see three different sets of information one might be interested in: A report on where everything stands,e.g., this afternoon at 4:00 p.m., an archive of this same snapshot of data taken every day (or every hour) over the last year, and a few webpages displaying the information sliced up by geographic area or water system equipment(tanks/pumps/flow), updated in real-time and displayed as a graph or numeric values.

The mechanics of providing access to these different sets of information should be easy and inexpensive. Any scada system operator could pull the snapshot report and email it to you. A year's worth of data can't be so much that it won't fit on a DVD. You may have to fiddle with Excel or Access to pull it into reports. And web access should be the easiest. A guest account, with authorization only to view specific information is how we provide similar access to our HVAC control systems.

Since you mention that the system already has web access, a guest account should not cost thousands of dollars to set up. So, it sounds like a FOIA request will be needed. That seems to be the usual way of doing business here in Illinois.

Best, B.O. July 11, 2008
Robert Old
Siemens Building Technologies, Inc., HVAC Products
1000 Deerfield Pkwy., Buffalo Grove, IL 60089-4513 USA
Phone: +1(847)941-5623, Skype: bobold2
[email protected]

Michael Griffin

Many (probably most) SCADA systems were never designed to be securely operated directly on the internet. At present, water and power utilities in the US are getting hammered on by the US government for their lack of security, so there's probably not a lot of appetite for making the SCADA directly accessable to the public, regardless of what others may have done in the past.

Modbus is a communications protocol used in industry. It doesn't "store" the data (although the field equipment often has short term storage so you don't lose any data if your communications go down temporarily). The data is then gathered by the SCADA system. The SCADA system is a piece of complex software that gathers the data from various field devices (located at the wells or reservoirs), stores it in a database, and then acts as a control panel for the operators. The "history" is usually stored in a database.

I don't know the legal aspects in your country, but it is likely the "record" is the contents of the history database. Many utilities use this history to review how their system has been operating over the long term so they can find the sources of problems and plan future capital expenditures.

If all you really want is to make things like historical flow, pressure, etc. data available to the publice, probably the simplest way to do it would be for the water utility to produce regular (e.g. weekly, monthly) reports in PDF format and post them on an existing web site (most utilities or governments have a web site of some sort). If they can post PR nonsense and vanity pictures of their managers, I'm sure they can post regular operating reports. The reports could be produced automatically by the SCADA (although it would have to be reprogrammed to do this).

If you are looking for live (up to the minute) data, then that's a much more difficult problem. You would realistically need to set up a separate web server with a live feed update from the SCADA database (or a separate mirrored database). That would be a good deal more expensive.

David Collins

Thanks for all of your replies. I eventually located as an example that real-time data can be made available on the Web a system driving a real-time data presentation from lakes in the El Dorado Irrigation District in California.

Their data is available at