Today is a big day for the Greens' Catherine Delahunty, who's taking the Party's rivers campaign to the Manawatu.

She's dropping by schools this morning, meeting with Iwi, then heading to the Horizons Regional Council to catch up on what they're doing to improve water quality.

Ms Delahunty said she'll then be heading down to the Manawatu River, where they'll do a water test with a new prototype Wai NZ water sensor.

She said the device "can measure oxygen in the water" as well as detect the pH level, the clarity of the water and how warm the water is.

"Eventually it'll be able to test the nitrates, phosphates and all kinds of things. So, what this does is it takes continuous readings and then sends that back to an app on your phone"

Ms Delahunty said it'll allow individuals and communities who have concerns about the quality of their rivers, to run tests without engaging local Councils.

Ms Delahunty plans to bring up the ongoing legal proceedings over the Council's 'One Plan' project.

She said the plan was meant to clean up pollution running off farms, but Fish and Game and Forest and Bird are taking the council to court because it hasn't been properly implemented.

Ms Delahunty believes the plan gives farmers an out.

"Even though the plan is really strict about reducing nitrogen in the river, there is an escape clause which means so long as they can show they are doing something to reduce their current levels they can get a 20-year consent, and that's not good enough."