In this fifth episode of RaboTalk’s Growing Our Future Catchment Catch-Up series, host Blake Holgate speaks with Mark Chrystall, a northern Rangitikei sheep and beef farmer and founding member and current Vice Chairman of the Rangitikei Rivers Catchment Collective (RRCC). Mark shares how the collective formed in 2017 to tackle localised riverbank feed-lotting issues and evolved into an expansive, data-driven entity. Today, the RRCC coordinates 125 monthly water testing sites and manages projects spanning sub-catchments across the Rangitīkei, Turakina, and Whangaehu rivers.
The conversation explores how catchment collectives can build regional trust, transition from raw water testing to advanced ecological indices, and address emerging environmental challenges. Mark highlights how spatial mapping, collaborative university research, and unified pest control projects help hill-country farmers take ownership of their landscapes, protect local freshwater quality, and build resilient rural communities.
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Show Notes:
Empowering Farmers Through Local Water Testing
Rather than relying solely on regional council monitoring, the RRCC established 125 monthly water testing sites across its sub-catchments. Testing for nitrogen, phosphorus, E. coli, and turbidity provides producers with transparent, localised data. Placing these real-time results directly in front of landowners creates instant buy-in and inspires peer-driven environmental improvement.
Uncovering Environmental Context via Science
In the Waikākahi tributary, monthly testing revealed phosphate levels nearly 20 times higher than expected. Rather than assuming agricultural runoff was the cause, the collective partnered with Massey University and Horizons Regional Council on a three-year PhD project. Geologic analysis revealed the elevated phosphate stemmed from natural rock formations rather than farming practices, illustrating the power of raw data over assumptions.
Moving Beyond Single-Metric Water Testing
The collective has expanded its environmental monitoring to include Macro-invertebrate Community Index (MCI) testing and habitat assessments across 80 sites. By training local coordinators to evaluate stream life, silting, and aquatic plants alongside regional council teams, the RRCC creates a complete, long-term picture of freshwater health across hill-country catchments.
Transitioning from Farm Plans to Integrated Catchment Plans
Building on individual Sustainable Land Use Initiative (SLUI) maps, the collective is aggregating farm data into comprehensive digital catchment plans. Layering spatial data for winter grazing, biodiversity, slope, and critical source areas allows the group to move past a scattered approach and direct environmental funding straight to high-priority hotspots.
Targeting Hotspots with Infrastructure and Pest Control
The RRCC actively tackles non-traditional environmental risks across the region. Projects range from fencing and planting native vegetation below gully wool-sheds to capture nutrient runoff, to launching a multi-regional thermal drone survey to map wild deer populations. Quantifying pest damage on winter forage crops allows the collective to design coordinated, landscape-scale control strategies.
Final Advice: Understand Your Footprint and Stay Connected
Mark encourages farmers and community leaders to proactively understand their environmental footprint rather than waiting for regulatory mandates. Keeping local sub-catchment groups active, sharing spatial data, and gathering at the local hall for a cup of tea or a sausage sizzle creates the social cohesion needed to navigate future land management challenges together.
