Thread by @WardHydro

🚨New Pub🚨
Love #WOTUS & #CleanWaterAct? Us too! A state-wide analysis of #wetland protections in #NewYork

New pub from @JeffWadeHydro @hydrochrista @BeckySchewe30 dropped today in @HydroProcesses

Key findings 🧵

doi.org/10.1002/hyp.14…

We ask how changes to the legal definition of #WOTUS under the Clean Water Rule & Navigable Waters Protection Rule alter which wetlands are protected as a function of landscape position and size, taking New York as our case study (largest geographic analysis to date)

Methods for landscape analysis follow closely after existing studies, largely this one from @RileyKWalsh
doi.org/10.3389/frwa.2…

Bottom-line-up-front.
On a HUC-by-HUC basis, both rules have the potential to reduce wetland protections. The Clean Water Rule has the more severe impact to federal protections.

Now deeper dive - which wetlands exist in New York? We stratified them based on their size (y-axis) + distance from a stream (x-axis). Awesome #DataVis to communicate: how many? how large? where? in a single panel! So these are the wetlands we may want to protect.

Here's how those same wetlands shake out if we look at the ones that are:
(left) protected by rule in the CWR;
(middle) possibly protected pending a Significant Nexus determination in the CWR
(right) protected by rule in the NWPR

Note the NWRP doens't have any 'conditional' category. Either you're protected by virtue of adjacency, or you're not.

Both the CWR & NWRP preferentially protect (a) wetlands that are closer to streams (see prior figure), and (b) larger wetlands.

Put another way - the biggest changes are for the smallest, non-adjacent wetlands. We know these matter from an ecological perspective, but they are where the regulatory battle is being waged, so to speak.

In comparison to the CWR, the NWPR decreases the total area and number of wetlands protected in NY. State-wide, we estimate that the NWPR protects 13.6% less total wetland area than the CWR, with a potential for greater losses depending on the CWR's significant nexus test.

This ⬆️ is in good agreement with another recent pub, tracing how the need for clarification in rulemaking has been pushing upstream and out of the flowing channel for 50+ years
doi.org/10.1002/wat2.1…

Finally - good stuff buried in the supplement.

Here's a look at how this plays out on a HUC-by-HUC basis. No clear gradients in space nor with geologic setting.
(this figure is for % of total wetland area)

More good stuff buried in the supplement. Same structure and findings (no clear spatial patterns) but on the basis of number of wetlands instead of wetland area.

Is this perfect? Far from it. Site-specific evaluations and decisions with boots-on-the-ground study will always be needed - we strongly agree with the agencies on this front.
See their mapping fact sheet here:
epa.gov/sites/default/…

The fact sheet notes:
IT IS THE CONSISTENT POSITION OF THE AGENCIES THAT NO MAPS EXIST THAT IDENTIFY THE SCOPE OF “WOTUS”

So then why do this analysis? Because if we allow the 'we can't map it' argment to prevail, that means policies are being made without ANY sense of the implications.

We DO have the ability to assess potential changes in federal protection as part of the rulemaking process.

To be clear, when agencies make maps they have regulatory meaning - their mapping jurisdiction is a weighty and consequential matter.

When academics like us make maps, we are exploring the possibilities & accepting uncertainties, but we still believe these are meaningful.

While regulatory determinations based on spatial data may be imperfect, broad-scale geospatial evaluations of wetland policy still provide considerable utility. For example, preliminary assessments of wetland jurisdiction and changes may be quite informative to policymakers.

@EPA @EPAwater are actively revising #WOTUS rules, and we are providing the evidence they need to understand potential impacts. #EnvironmentalPolicy #WaterPolicy

With yet another #WOTUS revision on the horizon, it is a crucial time to consider the implications of existing science and to evaluate how changes to federal regulations will impact wetland protections and the environment at large.

The impacts of regulatory change on wetland protections are highly variable across regions. We discourage the extrapolation of watershed-scale policy outcomes to broader regions and suggest that a comprehensive approach is necessary to understand regulatory impacts.

Given ⬆️, we suggest an approach like this one could be carried out across all states or eco-regions to provide some comprehensive, uniform, preliminary assessment of implications

Finally, with its use of a surface water connection as criteria for jurisdiction, the NWPR preferentially protects larger wetlands close to the stream network, leaving smaller and more geographically isolated wetlands particularly vulnerable.

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