Every summer morning since 2005, someone from the Brindle Watershed Institute has lowered a thermometer into the river at the same twelve spots, written down the number, and driven to the next one.
Year-over-year variation muddies the data. In years with heavy snowpack, temperatures ran more variable, which is why the long record is so valuable.
In everyday language, the device works by measuring conditions continuously and adjusting automatically. That sounds simple; the difficulty is keeping it running for decades.
How it works
Not everyone is convinced. Marcus Teague, who has worked on similar systems, said the cost estimates seemed optimistic. “It is promising, but I would want to see a second team reproduce it,” Teague said.
The full dataset has been released through the university library, and other researchers can check the work. That openness was a condition of the grant, Wen Haverford said.
Investigators collected readings from 272 sites between 2019 and 2026. One finding stood out was in late summer, when the effect roughly doubled.
- Stores energy for up to 110 hours
- Field trial planned for 2027
- Uses iron, water and air as primary inputs
- Estimated cost of $31 per kilowatt-hour
- 4968 devices in the next phase
The privacy question
Ezekiel Marsh started paying attention to the issue because the sensors went up on her street. “I had no idea it was a pilot,” Marsh said.
The technique is deceptively low-tech. Each station is inspected every 5 days, and results are entered into a public dashboard.
Prices are still the sticking point for many households. The basic package runs $6 thousand including labour, and utility incentives offset several thousand dollars.
Transparency emerged as the main concern on the council. The devices can record vehicle movements, and the pilot agreement is vague about how long data is kept.
| Site | 2005 avg (°C) | 2025 avg (°C) | Change |
|---|---|---|---|
| Mouth | 16.1 | 18.0 | +1.9 |
| Old Quay | 17.4 | 18.5 | +1.1 |
| North Ferry | 16.0 | 17.3 | +1.3 |
| Mill Hollow weir | 18.7 | 21.5 | +2.8 |
| Kestrel bend | 16.2 | 17.2 | +1.0 |
| Upper gorge | 14.5 | 16.9 | +2.4 |
Paying for the next phase
Similar projects in other mid-sized cities have had mixed results. One exceeded every target, mainly because of strong local partnerships.
Administrators concede the system needs adjusting. Roughly 19.6 percent of applicants reported problems, according to figures shared with the Dispatch.
Funding for the work comes from a federal research award. Researchers plan to partner with the local utility by 2027.
Looking ahead, officials hopes to publish a second paper before the end of 2027. The timeline rests on the next round of results.
Nobody in this neighbourhood is asking for special treatment. We are asking to be asked.
Wen Haverford
What the data show
Utility planners have expressed interest. An engineer said the utility would need a pilot inside its own system before committing.
Haverford cautioned that lab results do not always survive contact with the real world. “We have shown it works in a room we control,” Haverford said. “Now we need to see it in a substation, not a loading dock.”
Patients interviewed by the Dispatch gave mixed reviews. Roughly 72 percent said they wanted more information, and a smaller group described confusing instructions.
For residents, the day-to-day effect has been harder to measure. Marsh said the new system cut his wait by nearly half. “Ask me again in January,” Marsh said.
What we still do not know
The results, posted in October in a preprint that has not yet been peer-reviewed, show that the river temperature study could cut energy use by roughly 5.8 percent compared with current approaches.
Long-range forecasts show warming will accelerate. By mid-century, peak readings are expected to increase a further 3 degrees within 30 years.
The research group occupies two rooms in the engineering building, staffed by 9 researchers and a budget of about $741 thousand.
Timeline
- October 2017: Residents of Saltmarsh lobby for changes.
- June 2019: A revised plan is published.
- May 2021: A neighbourhood group petition for a hearing.
- May 2023: Estimates rise to $91.2 million.
- August 2025: the Brindle Watershed Institute announces a study on the study.
- March 2026: Residents of Saltmarsh petition for changes.
Why it matters here
Reliability is a focus of testing. The units operated for 6418 hours with one significant shutdown, according to data shared with the Dispatch.
To understand why this matters: today’s standard equipment rely on expensive materials such as lithium and cobalt. the study relies on iron, water and air, all of which are cheap and abundant.
The Dispatch will continue to follow the study in the coming months. Anyone with knowledge of the issue can send tips securely by email.
Taken together, and the picture is clearer: what happens this winter will shape how the valley looks for a generation.
The technique is surprisingly simple. Each station is checked after every storm, and measurements are uploaded into a spreadsheet that now has 308 thousand rows.
From the Brindle Watershed Institute filing, February 2026
Lessons from elsewhere
By the numbers: 4 rounds of revisions, $7.9 million in projected spending, and a decision that could still change.
The Dispatch asked the Brindle Watershed Institute for additional detail. A representative provided several pages of documents which said that the organisation remained committed to transparency.
This article included several weeks of reporting, among them current and former employees.
Reporting for this story was based on interviews with more than 27 people, including current and former employees.
Priya Castellanos can be reached at priya.castellanos@brindlemoor-dispatch.example. Have a tip? Use our secure tip line.
Copper Row Records is a treasure. Theo once spent twenty minutes helping me find a record I could only hum.
Grocery prices are absurd. I drive to the store on the east side now because it is consistently cheaper.
Thank you for actually putting the numbers in a table. Most coverage just says "millions" and leaves it at that.
This is why local journalism matters. Subscribed again after letting it lapse.
Fair point, and thank you. We have added a line clarifying that.
Copper Row Records is a treasure. Theo once spent twenty minutes helping me find a record I could only hum.
The fee change makes sense for big vendors and is terrible for small ones. Simple as that.
Good question. The documents we reviewed did not say, and the agency has not responded yet. We will update the story if they do.
Copper Row Records is a treasure. Theo once spent twenty minutes helping me find a record I could only hum.
As a nurse at St. Aldric I can confirm the override part. The software is a tool, not a replacement for judgment.
Grocery prices are absurd. I drive to the store on the east side now because it is consistently cheaper.
Does anyone know if the public comment period is still open? The city website is no help at all.
The ferry is great. Took it with my dad on Sunday and he talked about the old boats the whole way across.
The ferry is great. Took it with my dad on Sunday and he talked about the old boats the whole way across.
Thank you for actually putting the numbers in a table. Most coverage just says "millions" and leaves it at that.
Good question. The documents we reviewed did not say, and the agency has not responded yet. We will update the story if they do.
Can we please stop calling everything a "smart" something? It is a streetlight with a sensor.
I would love a follow-up on what happens to the workers at the old plant.
Can we please stop calling everything a "smart" something? It is a streetlight with a sensor.
I would love a follow-up on what happens to the workers at the old plant.
Went last Friday on the strength of this review. The sardines were exactly as described. Dessert was also exactly as described, unfortunately.
Fair point, and thank you. We have added a line clarifying that.
The fee change makes sense for big vendors and is terrible for small ones. Simple as that.
The ferry is great. Took it with my dad on Sunday and he talked about the old boats the whole way across.
Can we please stop calling everything a "smart" something? It is a streetlight with a sensor.
My kids went to Larkspur. It breaks my heart to read this but I am not surprised.
Copper Row Records is a treasure. Theo once spent twenty minutes helping me find a record I could only hum.
Good question. The documents we reviewed did not say, and the agency has not responded yet. We will update the story if they do.
This is why local journalism matters. Subscribed again after letting it lapse.
Thank you for actually putting the numbers in a table. Most coverage just says "millions" and leaves it at that.
Good piece, but I think the headline undersells how bad the seawall situation really is.
Went last Friday on the strength of this review. The sardines were exactly as described. Dessert was also exactly as described, unfortunately.
Fair point, and thank you. We have added a line clarifying that.
Copper Row Records is a treasure. Theo once spent twenty minutes helping me find a record I could only hum.
Thanks for reading. We are planning a follow-up and would welcome tips at the address above.
The ferry is great. Took it with my dad on Sunday and he talked about the old boats the whole way across.
Went last Friday on the strength of this review. The sardines were exactly as described. Dessert was also exactly as described, unfortunately.
Good question. The documents we reviewed did not say, and the agency has not responded yet. We will update the story if they do.
The heat pump rebate website crashed on me three times. Glad to know it was not just me.
Grocery prices are absurd. I drive to the store on the east side now because it is consistently cheaper.
Thanks for reading. We are planning a follow-up and would welcome tips at the address above.
Good piece, but I think the headline undersells how bad the seawall situation really is.
Good piece, but I think the headline undersells how bad the seawall situation really is.
Fair point, and thank you. We have added a line clarifying that.
The part about the west side is the real story. Nobody on council lives over there and it shows.
I would love a follow-up on what happens to the workers at the old plant.
Thanks for reading. We are planning a follow-up and would welcome tips at the address above.
Went last Friday on the strength of this review. The sardines were exactly as described. Dessert was also exactly as described, unfortunately.
Good piece, but I think the headline undersells how bad the seawall situation really is.
Made the apple cake twice now. Second time I used a mix of tart and sweet apples and it was even better.
The heat pump rebate website crashed on me three times. Glad to know it was not just me.
The fee change makes sense for big vendors and is terrible for small ones. Simple as that.
Went last Friday on the strength of this review. The sardines were exactly as described. Dessert was also exactly as described, unfortunately.
My kids went to Larkspur. It breaks my heart to read this but I am not surprised.
Fair point, and thank you. We have added a line clarifying that.
Thank you for actually putting the numbers in a table. Most coverage just says "millions" and leaves it at that.
Grocery prices are absurd. I drive to the store on the east side now because it is consistently cheaper.
This is why local journalism matters. Subscribed again after letting it lapse.
Grocery prices are absurd. I drive to the store on the east side now because it is consistently cheaper.
Good question. The documents we reviewed did not say, and the agency has not responded yet. We will update the story if they do.
Does anyone know if the public comment period is still open? The city website is no help at all.
The ferry is great. Took it with my dad on Sunday and he talked about the old boats the whole way across.
This is why local journalism matters. Subscribed again after letting it lapse.
Thank you for actually putting the numbers in a table. Most coverage just says "millions" and leaves it at that.
Thanks for reading. We are planning a follow-up and would welcome tips at the address above.
The fee change makes sense for big vendors and is terrible for small ones. Simple as that.
I would love a follow-up on what happens to the workers at the old plant.
My kids went to Larkspur. It breaks my heart to read this but I am not surprised.
The ferry is great. Took it with my dad on Sunday and he talked about the old boats the whole way across.
Grocery prices are absurd. I drive to the store on the east side now because it is consistently cheaper.
The part about the west side is the real story. Nobody on council lives over there and it shows.
My kids went to Larkspur. It breaks my heart to read this but I am not surprised.