The patchwork governance of ecologically available water: A case study in the Upper Missouri Headwaters, Montana, United States

Institutional authority and responsibility for allocating water to ecosystems (“ecologically available water” [EAW]) is spread across local, state, and federal agencies, which operate under a range of statutes, mandates, and planning processes. We use a case study of the Upper Missouri Headwaters Basin in southwestern Montana, United States, to illustrate this fragmented institutional landscape. Our goals are to (a) describe the patchwork of agencies and institutional actors whose intersecting authorities and actions influence the EAW in the study basin; (b) describe the range of governance mechanisms these agencies use, including laws, policies, administrative programs, and planning processes; and (c) assess the extent to which the collective governance regime creates gaps in responsibility. We find the water governance regime includes a range of nested mechanisms that in various ways facilitate or hinder the governance of EAW. We conclude the current multilevel governance regime leaves certain aspects of EAW unaddressed and does not adequately account for the interconnections between water in different parts of the ecosystem, creating integrative gaps. We suggest that more intentional and robust coordination could provide a means to address these gaps.

meteorological, agricultural, hydrologic, and socioeconomic; Wilhite, 2000;Wilhite & Glantz, 1985).Recognizing that these categories leave out important ways in which humans and hydrology interact (e.g., hydrosocial cycle; Budds et al., 2014), recent research has sought to expand or reframe these traditional definitions.For example, Van Loon et al. (2016) reframed drought to include how human processes drive and modify the development of drought.Vörösmarty et al. (2010) argued that, "The success of integrated water management strategies depends on striking a balance between human use and ecosystem protection" (p.555).However, water governance and policies during drought are generally rooted in a human-centric perspective that focuses on minimizing economic losses to agriculture and municipal water supplies (Ding et al., 2011;Jaeger et al., 2019;Jedd, 2019;Kallis, 2008).The impacts of drought on ecosystems have traditionally received little attention.
Yet humans benefit from ecologically available water (EAW) through the various ecosystem services it supports (Meldrum & Huber, 2019;Raheem et al., 2019).Crausbay et al. (2017) introduced the concept of ecological drought to emphasize the significant effects drought can have on species, ecosystem function, and the ecosystem services that humans derive from them.According to the Ecological Drought Framework (Crausbay et al., 2017), what fundamentally determines the impacts on a species or ecosystem during a drought is the decline in EAW (Box 1).EAW is the amount of water available to ecosystems for meeting specific ecological requirements, or sustaining key functions (e.g., photosynthesis).The amount of EAW varies according to geographic factors (e.g., slope aspect, soil types, topography) and weather patterns, which in turn vary due to anthropogenic climate change.Importantly, EAW is also influenced by humans through direct regulation of streamflows and groundwater discharge or indirectly through activities such as land management (e.g., forest thinning or urbanization [Arthington, 2012;Wohl, 2020]).
Even when EAW is a priority, it can be difficult to maintain, because it is often difficult to precisely define the amount of water a certain system needs until that water is unavailable (Pedro-Monzonís et al., 2015).Given the threshold nature of many ecological impacts of drought (Crausbay et al., 2020), by the time managers or water users recognize a drought is occurring, it may be too late to remedy the damage to F I G U R E 1 Illustration of ecologically available water as it relates to selected components of the hydrologic cycle.Fluxes of water originating from atmospheric (precipitation) and hydrologic sources (e.g., streamflows, groundwater) influence species in many different ways and collectively drive ecosystem processes.Human manipulation of water fluxes through consumptive use (e.g., groundwater or surface water extraction), flow regulation (e.g., environmental flows), or other actions act synergistically to influence ecologically available water.The cross section of an ecosystem depicted here, ranging from the top of the canopy layer to bedrock, is roughly equivalent to definitions of the Critical Zone that are often employed in ecohydrology (Giardino & Houser, 2015).Direct use of water is indicated to mean direct uptake by an organism (e.g., drinking or use of habitat by aquatic species), whereas indirect use is related to processes that are not related to direct uptake (e.g., herbivory that is influenced by water uptake by plants).ecosystems.For example, rangeland managers and agricultural landowners may not take action when condition warnings indicate a "flash" drought is occurring (characterized by rapid intensification; Otkin et al., 2022) until they see unmistakable signs of damage, such as reduced forage growth (Haigh et al., 2019).Beyond limitations related to human understanding of EAW, the management of EAW is further complicated by the fact that governance is dispersed across various spatial scales, sectors, and administrative boundaries.

| Multilevel water governance
Water governance is a cross-cutting endeavor that spans sectors and levels (Gupta et al., 2013;Pahl-Wostl, 2015), forming a multilevel collection of institutions and governance mechanisms that has been termed a "quilt" of governance (Rosenau, 1995) or a "policy assemblage" of "complex networks of government and non-government actors and organizations working to develop and enact policy" (Savage & Lewis, 2018, p. 119).With regard to EAW, water governance describes an overlapping patchwork of water and other natural resource management institutions and mandates that together determine the net amount of water available to ecosystems under both normal and drought conditions.
Multilevel governance theory describes decision-making that crosses organizational and ecological levels (Andonova & Mitchell, 2010) and includes multiple and diverse actor types (Biermann et al., 2010); as such, it includes iterative processes to engage a range of interests (Nilsson & Persson, 2012).For example, public managers often collaborate with other agencies and are embedded in multi-organizational networks that allow them to solve problems that a single organization could not (O'Leary et al., 2009;Pahl-Wostl, 2015).Yet by their very nature, multilevel systems do not have a single organizing entity or set of principles (Rosenau, 1995); instead, decisions result from the aggregated actions of many individual and institutional actors (Cravens, Henderson, et al., 2021).Water management in the western U.S. is a quintessential example of multilevel governance (e.g., Nelson, 2012;Ulibarri & Escobedo Garcia, 2020).
In such a governance landscape, where responsibility for governing EAW belongs to many entities and is not clearly delineated, certain aspects of EAW may remain unmanaged.As a result, multilevel governance can also lead to situations where-rather than power being shared between entities-there is a power vacuum and governance tasks remain undone.Bergsten et al. (2019) identify two types of "governance gaps:" integrative gaps emerge when interdependent issues are not recognized and managed as such, and collaborative gaps arise when those managing the same issues do not work together (also see: Hamilton et al., 2021).Integrative gaps are particularly relevant to the challenge of EAW since management activities are often not aligned with ecosystem processes (Fried et al., 2022).For example, political jurisdictions are not generally organized according to ecohydrological processes (Cohen & Davidson, 2011).
Recognition of the challenge of coordinated water management in the western U.S. has been particularly acute in the face of significant water scarcity and/or widespread drought conditions.In response, the Western Governors' Association (WGA) has been a driving force in calling for the integration of water management (Wilhite, 2016).Following a severe drought in 1996, the WGA created the WGA Task Force; this body called for a comprehensive approach to drought management (Wilhite, 1997), leading to the passage of the National Drought Policy Act in 1998 (Public Law 105-99) and a report on preparing for drought (NDPC, 2000).Another drought in 2004 led to an updated report; in Creating a Drought Early Warning System for the 21st Century, the WGA argued that the lack of a coordinated federal drought policy results in an ad hoc, crisis management approach (WGA, 2004).Ecologically available water is the quantity, timing, and quality of water that is available to ecosystems considering all incoming (e.g., precipitation, runoff, groundwater) and outgoing (e.g., evaporation, transpiration, human water use) processes that alter the availability of water to organisms within the system (Figure 1).This definition is premised on the notion that a certain level of EAW is needed to directly meet basic physiological requirements for a species' growth and survival as well as to indirectly meet requirements for foraging, refuge, reproduction, movement, or other essential activities that allow species to persist and ecosystems to function.In other words, moisture or water thresholds in part define where species can persist and thrive (e.g., Stephenson, 1998).EAW is an integrated concept that encompasses all water available to ecosystem components, including the concepts of "environmental flows" commonly applied in rivers (Arthington, 2012) and "plant available water" (Kulik, 1962).This less species-specific definition is needed not only because key thresholds for species are challenging to determine and can vary geographically and over time, but also because different species in the same system would likely show different thresholds.Available measurements are often limited to system-level patterns, such as how soil moisture relates to plant productivity or how flow modifications affect water quality, a subset of "indicator" species, or the hydromorphological structure (Grizzetti et al., 2016).In this way, EAW complements the concept of ecological drought, which encompasses impacts on all terrestrial and aquatic ecosystem components, as well as impacts on related ecosystem services that support societal values (Crausbay et al., 2017).
drought resilience capacity (The White House Archives, 2016).Implementation of the NDRP focused on two demonstration projects, one of which, the NDRP Montana demonstration project, served as the focus of this research.
Analysis of multilevel and boundary-spanning water governance in the legal literature has been based largely on evaluating statute-based or judge-made "law on paper" (e.g., Engel et al., 2019;Merrill, 1997;Thompson, 2012).By contrast, this research proceeds from the long-held law and society objective to describe the "messy reality of the living law"-often a far cry from the formal law in books, and even, as known by lawyers (Macaulay et al., 2007, p. 19;Pound, 1910).It responds to calls for greater studies of "law in action" in environment-related legal contexts, noting that empirical studies dealing with state water law are rare (Fischman & Barbash-Riley, 2018).We contribute to a small, but growing body of law-based work that uses empirical methods, including interviews and a focus on a specific place (e.g., Kaiser & Binion, 1998;Loomis & Ballweber, 2012;Robison et al., 2021) and analysis of water-related planning documents (e.g., Arnold, 2010) to examine how waterrelated laws operate and are perceived by key stakeholders.We extend existing work dealing with environmental water (e.g., Kaiser & Binion, 1998;Loomis & Ballweber, 2012;Robison et al., 2021;Womble et al., 2022) by going beyond surface water flows to examine the broader context of EAW (Box 1).

| Governing ecologically available water in the Western United States
While society derives significant benefit from adequate EAW in an ecosystem, that benefit can be diffuse and difficult to isolate or quantify.
In economic terms, the benefits of sufficient EAW, like many services provided by healthy ecosystems, are a public good.A resource is considered a public good if it is (a) non-excludable, that is, it is infeasible for one user to exclude other people from using it, and (b) non-rivalrous, that is, one person's use does not prevent another person's use (Samuelson & Nordhaus, 2010).While economic damages during a drought can be used as a proxy measure for the value of functioning ecosystems (e.g., Banerjee et al., 2013), efforts to compensate water users for the benefits of EAW have historically been overlooked by water planners (Emerton & Bos, 2004).As is the case with many ecological resources, its public-good nature often results in a tendency to undervalue and thus under-protect EAW (Brunckhorst, 2002).Contributing to this issue is the diffuse governance of EAW.
A broad range of water-specific institutions are relevant to managing EAW, including water laws, water-sharing rules, irrigation practices, and beliefs about the use of rivers and lakes (Hassenforder & Barone, 2019).Furthermore, because EAW is integrated across many systems and sectors, we presume that an even broader range of governance mechanisms need to be accounted for.These include laws, policies, administrative programs, and planning processes aimed at managing other natural resources (e.g., forests or rangelands) or at helping communities prepare for and respond to drought (e.g., drought plans; McEvoy et al., 2018).
The heart of water governance in most of the western U.S. (including Montana) is the legal doctrine of prior appropriation (Fanning et al., 2014;Montana Code Ann. 85-2-401).Under this system, applicants are prioritized to receive water rights defining quantity, timing, and type of permissible use based on who used the water first, specifically for beneficial purposes.Under the original 19th century formulation of prior appropriation, "beneficial uses" included the diversion of water from streams for consumptive uses, such as agriculture, domestic use, and industry, thus leaving essentially all aspects of EAW formally ungoverned until the 1950s (Thompson et al., 2018).Water governance regimes have evolved significantly in the past century and a half.One of the most important trends has been increasing concern for EAW, in the context of Montana (MT DNRC, 2018), the western U.S. (e.g., Bushong, 2015;MacDonnell et al., 1993), and in other nations (e.g., Eckstein et al., 2010;Mount et al., 2016).Instream flow laws and policies now expand prior appropriation's definition of permissible "beneficial" uses to include leaving water in the river for ecological or recreational purposes (Stalnaker et al., 1995).
EAW may also be directly or indirectly influenced by a diverse set of planning and permitting processes, administrative operations, and other laws; this range of governance mechanisms provided the rationale for our study.Plans (e.g., water supply plans, drought plans, hazard mitigation plans), administrative operations (e.g., reservoir operating plans), permitting processes (e.g., dam licensing and relicensing), and other laws (e.g., Clean Water Act; 33 U.S.C. § 1251 et seq.) can directly affect EAW by governing water supply, water quality, and drought preparedness or response.Other governance mechanisms can indirectly affect EAW, such as land management plans and laws that shape the use and composition of forest, riparian, and other ecosystems, which then influence EAW, or wildlife management plans and laws (e.g., the Endangered Species Act [ESA; 16 U.S.C. § 1531 et seq.]) that aim to protect economically important or special status species and their habitats, in which EAW is a vital component.
In this study, we analyze the component parts of the multilevel governance quilt in the Western U.S. using a detailed case study of one location: the Upper Missouri Headwaters Basin in southwestern Montana (Section 3.1).We draw on two complementary datasets.First, as part of a larger project, we conducted 44 semi-structured interviews with managers and stakeholders in the basin (Section 3.2).Second, we analyzed planning documents created by institutions in the basin (Section 3.3).We combined analysis from the interviews and documents to investigate the following research questions: (1) Which agencies and institutional actors make decisions that determine how much water is available for ecosystems?; (2) Which governance mechanisms are used (including laws, policies, administrative programs, and plans) ?; and (3) To what extent do governance gaps exist?Which aspects of water for ecosystems remain unmanaged?We report on the range of agencies and institutional actors that play a role in governance in the UMH (Section 4.1) and the governance mechanisms, including laws, policies, and administrative programs, on which they rely (Section 4.2).We then mapped each governance mechanism to the ecosystem(s) in which it played a role, revealing where EAW is addressed and where gaps exist (Section 4.3).We end with a discussion and conclusion (Section 5), highlighting how the current multilevel governance regime leaves certain aspects of EAW unaddressed and does not adequately account for the interconnections between water in different parts of the ecosystem, creating integrative gaps.We suggest that more intentional and robust coordination could provide a means to address these gaps.

| Case study description
In 2014, the Upper Missouri Headwaters (UMH) Basin was selected as one of two NDRP demonstration projects (NDRP, 2017).The overall NDRP goal was to build drought resilience across jurisdictions through the development of watershed drought plans and other coordinating activities.The Montana demonstration project (MT NDRP hereafter) involved local drought coordinators from eight tributary watersheds.
Within its first several years, the demonstration project leveraged over $2.4 million for projects and capacity building (Schwend, 2016).This effort to develop watershed drought plans was led by the Montana Department of Natural Resources in coordination with local, state, federal, and non-governmental partners (see Montana Drought Demonstration Partners (2015) for a full list of partners).The UMH made an ideal case study to examine the intersection of EAW and multilevel governance because of the attention paid to water, drought, and ecological impacts by the diverse governmental and non-governmental partners working under the auspices of the MT NDRP (Cravens, McEvoy, et al., 2021).
The Upper Missouri Headwaters Basin is located in the southwest corner of Montana covering roughly 8.6 million acres bordering Yellowstone National Park (MT DNRC, 2014).It includes three forks of the Missouri River: the Jefferson, Madison, and Gallatin Rivers.These rivers are fed by the Red Rock, Beaverhead, Big Hole, Ruby, and Boulder Rivers.Streams in the UMH are mostly fed by snowmelt with highest streamflow between late May and mid-June.The basin contains a majority of publicly owned lands and fewer private lands (MT DNRC, 2014), which means there is a complex set of federal, state, and local institutions at play.The region is recognized for its high conservation and recreational value, including as habitat for iconic species like wolf (Canis lupus) and grizzly bear (Ursus arctos horribilis), as an international migration corridor for species like pronghorn antelope (Antilocapra americana) and for world-class trout fishing (Carparelli, 2016;Cline et al., 2022).Most communities are rural, and many livelihoods depend on agriculture or tourism.Across the larger Upper Missouri Basin, almost 98% of the annually diverted surface water is used for irrigation (MT DNRC, 2014).The UMH basin is prone to frequent drought and, according to the United States Drought Monitor, has been in moderate drought or higher approximately 62% of the time since the map began in 2000 (U.S. Drought Monitor, 2022, https://droug htmon itor.unl.edu/DmData/TimeS eries.aspx).The region is also experiencing rapid population growth; for instance, Gallatin County's population grew by 37.1% between 2010 and 2021 (U.S. Census Bureau, 2021).

| Interviews with MT NDRP partners
Our team of interdisciplinary researchers conducted 44 semi-structured interviews with 48 individuals representing 30 different local, state, or federal MT NDRP partners.The sampling strategy was to interview representatives from as many MT NDRP partners as possible.Most interviews took place with one individual, but in three cases, an individual requested additional staff from the same organization to participate.
Focusing particularly upon ecological drought, the interview protocol assessed participants' definitions of drought; drought impacts they managed or considered of particular concern; uses for drought science and monitoring data, and gaps within it; methods of drought preparation and response; and innovative drought management solutions used or encountered.(See Cravens, McEvoy, et al. (2021) for more detail about the sampling strategy and a copy of the interview protocol).
After the interviews were professionally transcribed, three researchers open-coded 10% of the sample to isolate emergent themes (Corbin & Strauss, 2008) and identified themes by consensus to generate a coding rubric.The remaining interviews were coded with these themes in NVIVO 11 (QSR International) by a single researcher.Later, more complex or larger themes (e.g., definitions of drought, ecological drought impacts) were broken down and re-coded.
In this paper, we report on the data originally coded as "Regulatory Context," much of which was generated in response to the question, "How does the regulatory context influence your ecological drought preparedness and response efforts?"Data coded as "Regulatory Context" in first round coding was re-coded to identify the agency or institutional actor involved; the specific governance mechanism being described; remarks about coordination between agencies; and (to the extent possible) whether the respondent believed those laws, polices, or programs to be an aid or hindrance to managing EAW.

| Analysis of planning documents
A range of local, state, and federal entities have mandated planning functions that affect EAW.To complement our interview data, we analyzed planning documents from the various overlapping political jurisdictions and hydrological subbasins that comprise the Upper Missouri Headwaters region (Figure 2).
Our goal was to analyze all plans pertaining to the study region that might impact the governance of EAW.We searched within jurisdictional categories, from federal to state to local.We categorized the resultant plans as follows:  S1 for definitions and general plan format description; see Table S5 for statutory frameworks for plans).
Through internet research and contacting agencies, we generated a final list of 33 relevant plans that applied to the study region (see Table S2 for plan details).The sample included all plans that we were able to identify and obtain, including local (i.e., municipalities, counties, conservation districts), state, and federal agencies as well as watershed and basin plans.Note that since the plan search was based on the geographical region boundaries, there is not perfect correspondence between NDRP partner organizations and selected plans.For instance, the Red Rock Lakes National Wildlife Refuge was not an active NDRP partner, but we included the conservation plan from the refuge in the study.Combining interviews with NDRP partners and documents selected based on the study region itself provided us two complementary lenses for assessing the complexities of how and by whom EAW is governed in the UMH.
After gathering electronic copies of plan documents, each plan was qualitatively coded in two rounds.In the first round, each plan was analyzed by at least two researchers, using an initial set of criteria to capture the plan name, type, lead agency, date of adoption, plan rationale, extent to which it addressed drought, if it included general measures to be more prepared for drought, whether there were mitigation foci on water supply or conservation, if there were triggers for action, specific response measures, and if it required coordination with other jurisdictions.Extensive discussion among the whole research team ensured interrater reliability.When the results of this initial coding revealed significant variation in whether and how the various types of plans addressed water in general and ecological impacts of water shortage in particular, we created a detailed second round coding scheme through extensive team discussion (Table S3) to analyze whether and how each plan addressed EAW and ecological impacts of drought.A single researcher then used that scheme to reanalyze the entire document dataset.For each plan, we coded all text related to preparing for, responding to, or identifiable indirect effects on (e.g., city water use efficiency upgrades) shortages in EAW.We identified influences on EAW broadly as any mention of water currently or anticipated to affect health or function of ecosystems or non-human species, or other uses of water that were identified as resulting in increasing or decreasing the amount of water available for ecosystems or species.We report here the findings from this second round of coding.

| Agencies that can influence EAW
As a resource that does not easily fit within traditional agency divisions, responsibility for EAW is spread across multiple jurisdictions and types of agencies across a large spatial scale.Agencies or institutional actors that make decisions or take actions related to water quantity, quality, and natural resources that depend on water all may influence EAW. Figure 3 depicts the agencies and other institutional actors we identified in the interviews and plan analysis that influence EAW in the Upper Missouri Headwaters.Table S4 provides Seaber et al., 1987) within the study area (HUC 6 size), while also showing the range in elevation that provides the natural boundaries for the subbasins within the study area.Within the study area, many of the drought plans and watershed restoration plans are implemented at the subbasin scale.Map (d) provides an overlay of the counties (political boundaries) that overlap the study area, while also including the City of Bozeman, which also has its own water management plan, separate from those at the subbasin level.Map (e) shows the two Bureau of Land Management (BLM) field office areas that overlap with the study area.Finally, Map (f) shows the major national forests within the study area (Beaverhead-Deerlodge and Custer Gallatin National Forests) that the United States Forest Service (USFS) manages.Map (c) through Map (f) show the complexity of water governance due to overlapping hydrological unit, local, state and federal management boundaries.
(which are then described further in Section 4.2).While we attempted to be as thorough as possible, this may not be a comprehensive list of every agency and institutional actor that influences EAW in the study region, in part because not every entity has produced a relevant planning document or was mentioned in interviews.We also note that in a few cases, interviewees made passing references to agencies and/or governance mechanisms that may affect drought preparedness or response.However, we have left these out of Table S4 as not enough detail was provided to draw a clear link to EAW.For instance, one interviewee (UMH29) discussed U.S. Department of Agriculture (USDA) programs that provide insurance to ranchers and commented how these are probably "deleterious to actual drought planning," another (UMH23) described challenges landowners experienced participating in soil-focused conservation programs administered by the National Resources Conservation Service (NRCS), and a third (UMH40) described climatological information provided by the National Oceanic and Atmospheric Administration (NOAA).
We identified seven federal agencies, six state agencies, 18 local entities, seven watershed-scale institutions, and one basin-scale actor involved in the management of EAW in the study region, as well as one actor whose scale of operations is cross-cutting (Figure 3; Table S4).
Most are comprised of government employees from the same agency, though three types are comprised of a mix of governmental and F I G U R E 3 Actors involved in governance of ecologically available water at the federal, state, local, water basin, and watershed level, as well as one cross-cutting actor, in the Upper Missouri Headwaters Basin, southwestern Montana.Actors operating at levels with politically determined boundaries (i.e., federal, state, local) are on the left side of the graphic, whereas actors operating within ecologically determined levels (i.e., water basin, watershed) are on the right.Actors are derived from water-related planning document analysis and qualitative interviews.CD, Conservation District.See Table S4 for additional details.
non-governmental actors representing various agencies, entities, and interests (i.e., Montana Climate Change Advisory Committee, the Upper Missouri River Basin Advisory Council, the Watershed Committees/Councils).The Montana Drought and Water Supply Advisory Committee is comprised of representatives from multiple state government agencies (MT DNRC, 2021).The National Drought Resiliency Partnership (NDRP) was the only cross-jurisdictional actor we identified; the NDRP MT demonstration project was explicitly designed to address the problem of drought in a way that bridged scales and unified local knowledge with state and federal resources and capacity (Montana Drought Demonstration Partners, 2015).
The role of some entities is directly related to managing water quantity (e.g., US Bureau of Reclamation, Montana Department of Natural Resources and Conservation water resources division).However, the scope of most entities is broader, encompassing the management of water quality or other natural resources (e.g., US Environmental Protection Agency, US Fish and Wildlife Service, Conservation Districts).Some entities have both relevant regulatory responsibilities as well as influence on EAW as holders of water rights and/or instream flow rights (e.g., US Forest Service, Montana Fish Wildlife and Parks [MT FWP], Counties, and the City of Bozeman).This diversity of roles-sometimes played by the same entity simultaneously-means that understanding whose actions could influence EAW requires paying attention to the institutional actor being considered as well as the capacity in which an entity is acting.Interviewee comments suggested that actors may take action that is helpful for ecosystems and positively influences EAW in the system (e.g., MT FWP choosing to acquire a new instream flow right on a sensitive stream reach) or else decline to take action or actively impede others' actions so as to negatively influence EAW.For instance, one interviewee perceived that a lack of participation in water planning by the US Bureau of Reclamation was serving as a barrier to planning for drought resilience and ecological impacts: "Until the Bureau of Reclamation is actually willing to come to the table and talk about their role…I see any planning kind of running up against a wall administratively" (UMH30).
Thus, regardless of whether their role and scope are directly or indirectly related to water management, we found that a diverse range of entities influenced (or could influence) EAW in the Upper Missouri Headwaters.Given the importance of precisely understanding the role each entity is playing and how the entities relate to one another, the next section analyzes the governance mechanisms used by each institutional actor.

| Governance mechanisms that can influence EAW
The institutional actors described in Section 4.1 rely on diverse governance mechanisms-including laws, policies, and administrative programs, as well as local, state, and federal planning processes.The interaction of governance mechanisms across institutional actors and jurisdictional levels comprises the multilevel governance regime in the UMH.Some mechanisms enable or require organizations to take actions that provide water for ecosystems; conversely, some mechanisms enable or require action that provides water for other uses and thus indirectly contributes to insufficient EAW, especially in fully appropriated subbasins or during late summer scarcity or drought.
Figure 4 presents the laws, policies, administrative programs, and plan types mentioned by interviewees or included in the analysis of planning documents.It summarizes the role each governance mechanism plays in influencing EAW.(More detailed information about each governance mechanism can be found in Table S5) Given the complexity of any multilevel governance regime, we note this list is likely not comprehensive.However, it reflects how interviewees from NDRP partner organizations understand the relationship between governance and the management of EAW, particularly in times of water shortage, combined with insights about the management of EAW derived from analyzing an extensive corpus of planning documents that apply to the study region.Note that in some cases, the analysis suggested that the same governance mechanism can positively influence some aspect of EAW and simultaneously negatively influence another aspect.For instance, the Clean Water Act provides temperature standards designed to protect certain cold-water fish species from the impacts of water shortage (Section 303).But interviewees also described how the Clean Water Act can create disincentives for watershed restoration action on private land or by smaller organizations by requiring a Section 404 permit for restoration projects that result in sediment or other fill material discharge into certain streams.

| Laws
Interviewee comments emphasized the centrality of water law to the multilevel governance regime.Prior appropriation repeatedly emerged as an institutional barrier to effectively managing EAW.While perhaps not surprising given the extensive attention to this issue in the literature (e.g., Anderson et al., 2017;Ghosh et al., 2014;Macdonnell, 2014), these comments highlight the way that water law provides the baseline understanding of how and to whom water in the basin is distributed, which is the foundation for interviewees' understandings of the amount of water available for ecosystems.
The inflexibility of prior appropriation (e.g., Craig, 2020) and difficulty of transferring water rights (e.g., Womble & Hanemann, 2020) restricts creativity "in terms of using water in a different way" (UMH22) and shapes "how you can respond to drought, and particularly how you can mix in conservation of resources that are water dependent" (UMH24).Some managers felt that prior appropriation actively works against managing for EAW in times of drought, serving as a "pretty significant disincentive to thinking about drought response and drought resilience" (UMH21), particularly because of the constraints of the law's "first in time, first in right" provision.Other interviewees mentioned the "use it or lose it" rule (Montana Code Ann.85-2-404).A state official observed that although individuals might want to conserve water or pursue projects for ecological purposes, "they might hear that if they do so, that they're going to lose a part of their right" and alter their behavior accordingly (UMH34).
Interviewees also made many comments about instream flow rights, that is, water rights held by Montana Fish Wildlife and Parks for ecological purposes (McKinney, 1990).Instream flow rights were seen as one of the primary safeguards for aquatic ecological health within Montana's legal system.Interviewees agreed that instream flow rights provide a useful corollary to prior appropriation that allows for consideration and protection of EAW.However, they noted that instream flow rights as currently implemented focus primarily on the needs of fish, especially salmonid species.Instream flow rights also were noted as having significant limitations; notably, in many watersheds, they are junior to other rights, which means they provide little protection in times of water shortage.As one interviewee summarized, "We've spent 50 years trying to make sure that instream flows and aquatic protections are [sufficient].The way we've done that may turn out to be wholly inadequate to meet those expectations…we have such junior water rights for protecting the public resource…that [it] may give really poor protection of the ecological systems" (UMH26).
The other two laws mentioned by interviewees were the National Environmental Policy Act (NEPA) and the Endangered Species Act (ESA).Interviewees generally viewed NEPA's procedural requirements as a constraint to reacting as needed when drought occurs (e.g., to change terms of a grazing permit on BLM lands), though they did point out that in the best circumstances, the law's requirements can lead to F I G U R E 4 Governance mechanisms that influence ecologically available water, at the federal, state, local, water basin, and watershed level, in the Upper Missouri Headwaters Basin, southwestern Montana.Governance mechanisms are categorized as laws, plans, or administrative mechanisms.See Table S5 for additional details.
comprehensive assessment of ecological impacts before federal agencies take action.The ESA was much more extensively discussed by study participants, particularly the case of the Big Hole watershed, where the threat of listing arctic grayling (Thymallus arcticus) has led many water users to develop a plan to proactively mitigate the impacts of drought by participating in a Candidate Conservation Agreement with Assurances program (McEvoy et al., 2018).This suggests that in the Big Hole the ESA served as a "catalyst" (UMH6), motivating people to proactively address a problem before the law forced their hands.As one interviewee summarized, often the "threat of [action under the ESA] is actually far more persuasive than the actual regulatory mechanism itself, anything that can trigger people to work together" (UMH7).

| Administrative policies, permits and programs
We identified six relevant administrative policies, permits, or programs that influence EAW in the basin.Four of these were described by interviewees as mechanisms that can be used to protect water quantity (i.e., special use permitting, FERC licensing), quality (i.e., Superfund), and the species that are sensitive to water shortage (i.e., fishing closures).It was less clear whether the final two mechanisms, grazing regulations and Federal Emergency Management Agency (FEMA) floodplain regulations, have a positive or negative impact on EAW.Interviewees described the impact of grazing regulations as dependent upon how they are implemented, since rules governing grazing on lands managed by multiple-use agencies like the BLM require balancing long-term ecological health with the current productivity of rangelands (Bureau of Land Management, https://www.blm.gov/programs/natur al-resou rces/range lands -and-grazi ng/range land-health).FEMA floodplain regulations were the sixth mechanism in this category.One interviewee (UMH6) stated that the agency has traditionally only considered flood risks and not the "natural benefits of floodplains," impeding the protection of wetlands and the EAW they contain.However, FEMA has more recently recognized a wider range of floodplain benefits such as fish and wildlife habitat, biological productivity, erosion control, improved water quality, groundwater recharge, and recreational opportunities (e.g., birdwatching; FEMA, 2022).

| Plans
The study identified 12 types of plans (Table 1; also see Table S1 for full details) that play several roles in the governance of EAW in the study region.A first group of plans (HMPs, DPs, CPs) prepare for or respond to the hazard of drought, thus affecting EAW to the extent that they considered drought impacts on ecosystems.HMPs and DPs generally prioritized the human impacts of drought, considering EAW only as it relates to fishing and agriculture.The CP acknowledged that climate change may lead to increased drought, but most of the recommendations did not focus on drought or EAW.For example, it addressed wildfire, but did not connect drought to wildfire risk.A second group of plans (ROPs, WPs) managed water availability and reservoir water release, with direct implications for EAW.While the ROP for the region planned to release water for seasonal fishery needs, the fishery was not described as the priority during times of water scarcity.WPs may positively influence EAW if they accomplish stated management objectives (e.g., co-management of surface water and groundwater, maintenance of instream flows, reduced water consumption during drought, research on natural water storage).The basin water plan (WP2) explicitly discussed TA B L E 1 List of planning document types that play a role in the governance of ecologically available water in the Upper Missouri Headwaters Basin.For more detailed descriptions of each plan type, see Table S1. the need to manage forests and rangelands for watershed health and natural water storage and planned to consider ecological health in all new water storage and management decisions.The Bozeman city water plan (WP1) considered effects of planning on instream flow and the environment.While these plans provided important examples of incorporating EAW into the planning process, they could have been even more explicit in terms of goals and actions to address EAW.For example, the state water plan's (WP3) section on climate change did not mention drought nor fire.
A third group of plans (WSPs, HCPs) managed for water quality; actions called for in these plans such as streamside vegetation rehabilitation may also affect water availability.Due to funding constraints, proposed actions in WSPs appeared to be mostly suggestions or required enactment by other organizations.HCPs also managed water quality impacts on species (see final group description below), though none of the management objectives in HCP1 mentioned drought or low water levels, even for fish.A fourth group (FPs, WRPs, RPs, RMPs) managed their designated land units for mixed uses, ranging from recreation and mining to ranching, species conservation, and forest health.These plans influenced EAW mostly indirectly, such as through riparian vegetation management, though sometimes directly, such as through stream channel maintenance or cattle grazing management.The Forest Plans (FPs) in our document corpus played made almost no direct references to drought, and did not explicitly plan for it, despite planning for related events such as pine beetle outbreaks and wildfire.In contrast, the WRP we analyzed (WR1) planned extensively for the impacts of drought and climate change on wetland and instream habitat and recognized the need for "hands on" or adaptive management to address future challenges.A last group of plans (WHPs, HCPs) affected EAW in their management of specific species.While species management was the primary focus of WHPs, the HCP we analyzed (HCP1) managed species only insofar as they were affected by timber harvest and subsequent water quality issues, to comply with the Endangered Species Act.Generally, only aquatic species management, particularly fish, recognized an explicit or direct interaction with EAW.Most terrestrial species' management plans did not list drought as a threat, even for wetland species.
The publication date of the plans ranged from 1986 to 2017, with more recent plans more likely to address contemporary concerns such as climate change.For example, the two most recently created HMPs, from Jefferson and Madison counties in 2017, were the only two hazard plans to connect climate change to drought.However, later publication dates did not necessarily mean greater attention to ecological impacts of drought.For instance, the Red Rock Lakes National Wildlife Refuge Plan (WR1) and Beaverhead/Deer Lodge National Forest Plan (FP1) were both published in 2009, but the former planned much more extensively than the latter for drought and climate change, suggesting a significant amount of local discretion may have influenced the contents of an individual plan.
Within a multilevel governance system, certain responsibilities may not belong to an individual actor but rather are shared between multiple agencies or institutional actors.In these cases, vertical and horizontal coordination becomes an essential part of an agency's role (Pahl-Wostl, 2015).Federal, state, and local plans overlap in their coverage of aspects of EAW in the UMH.Coordination actions we coded within the planning documents took multiple forms, including collaboration on production of the document; coordination for management consistency between geographical areas or focal species; coordination between levels of government; coordination regarding planning documents made by one organization; explicit coordination with specific, relevant government organizations, tribes, non-profits, or other stakeholders to implement a plan; statements of broad intent to coordinate; intent to act as coordinator between other organizations; required compliance with state or federal laws (e.g., NEPA); and communication with local stakeholders when developing or implementing a plan.For instance, most federal plans (RPs, RMPs, FPs, WRPs) are tools to help agencies manage specific geographies within the UMH region and thus aimed for management consistency with neighboring landowners.In contrast, some state plans (CP1, DP6, WP3) are not geographically limited in their focus; thus, they served to coordinate actions among other actors.Local plans (HMPs, DPs, WSPs) applied only to specific counties or watersheds, with little apparent coordination.Interviewees overall made few comments about coordination and planning, but those they did make focused on how plan development (e.g., Forest Plan development) can serve as a framework for negotiating collaborative solutions to water use challenges, especially during drought (UMH36, UMH44).

| Governance mechanisms for EAW by ecosystem type
Ideally, to account for the public-goods nature of EAW, all valued aspects of EAW would be managed by one or more agencies and/or governance mechanisms within a multilevel governance regime.Our third research objective was to move beyond description to assess the extent to which the existing multilevel system of governance mechanisms and institutions in the UMH collectively manages EAW.To meet this goal, in this section, we compile insights from the two preceding sections to identify the ecosystems in which EAW is adequately accounted for by existing governance mechanisms and, conversely, identify the ecosystems in which EAW governance is less developed.
Figure 5 maps the governance mechanisms described in Section 4.2 to a set of six ecosystem types, adapted from Gregg and Kershner's (2019) description of U.S. West ecosystems affected by ecological drought (also see Table S6).For ease of interpretation, governance mechanisms within each ecosystem are roughly grouped according to the aspect of EAW affected (e.g., affecting water quantity or quality).
Governance mechanisms that positively influence EAW are displayed with black icons, and governance mechanisms that negatively influence EAW are displayed with red striped icons.More detailed explanation of how we mapped each governance mechanism to ecosystem type appears in Table S6.Taken as a whole, Figure 5 serves as a rough heat map for the level of EAW governance within each ecosystem type.However, most governance mechanisms affect EAW in specific ecosystems.Our analysis indicates that EAW in the aquatic ecosystem is addressed by the largest number of governance mechanisms, followed the riparian ecosystem.In contrast, EAW in the "marsh, bog, wetland" ecosystem category as well as the "shrubland, grassland, rangeland" category have far fewer governance mechanisms, and the "forest and woodland, sub-alpine, and alpine" ecosystem category has almost none.

| D ISCUSS I ON AND CON CLUS I ON
EAW is critical for ecosystems and associated ecosystem services.However, governance of EAW is not always explicit, spans multiple agencies, and can be influenced by a range of institutions that determine how scarce water is allocated between competing uses.The functions that water serves in the ecosystem go far beyond the habitat for specific aquatic species (e.g., salmonids), or even the management of the riparian corridor.Our finding that EAW is most directly accounted for through mechanisms focused on instream flows for salmonid fishes aligns with our previous findings from the analysis of indicators used in watershed-scale drought plans (McEvoy et al., 2018).EAW governance thus extends beyond traditional water management to include a wider range of resource governance actors and institutions that have the potential to influence the quantity, timing, and quality of water available to terrestrial and aquatic ecosystems.
To better understand EAW governance, we used a "law in action" and qualitative institutional analysis approach in the Upper Missouri Headwaters (UMH) basin to empirically (a) describe the patchwork of agencies and institutional actors whose intersecting authorities and actions influence the EAW in the study basin; (b) describe the range of governance mechanisms these agencies use, including laws, policies, administrative programs, and planning processes; and (c) assess the extent to which the collective governance regime creates gaps in responsibility.
Using a combination of semi-structured interviews and document analysis, we identified 40 agencies and institutional actors-across federal, state, local, basin, and watershed scales-that can influence EAW in the study region (Figure 3).It is notable that no single agency has explicit authority for managing EAW.Montana Fish, Wildlife and Parks, which holds water rights for instream flows under the Montana Water Use Act, is arguably the agency most directly associated with the management of EAW via instream flow rights and responsibility for aquatic species (see McEvoy et al., 2018).However, instream flows address only a narrow range of EAW concerns, leaving many other important ecological water needs unaddressed (e.g., Martin-Ortega et al., 2015;Vári et al., 2022).
We also identified a range of governance mechanisms, including six key laws; seven relevant policies, permits, or programs; and 12 types of plans that could influence EAW in this region (Figure 4; Table S5).Our interviews provided insights into the diverse ways that these governance mechanisms can positively and/or negatively influence EAW (Tables S5 and S6).For example, the Clean Water Act's temperature standards protect aquatic species (a positive influence) but interviewees emphasized that Section 404 may disincentivize watershed restoration because permits are difficult for landowners to obtain.We found that some governance mechanisms are more influential than others.For example, the Endangered Species Act served as a catalyst to incentive cooperation and action, particularly in the Big Hole watershed.We also found that more governance mechanisms are available for managing EAW in aquatic systems.In contrast, there are only a few governance mechanisms available for managing EAW in "shrubland, grassland, and rangeland" systems, as well as in "forest and woodland, sub-alpine, and alpine" systems (Figure 5; Table S6).
Lastly, we identified two integrative gaps (i.e., gaps that arise when interdependent issues are not recognized and managed as such [Bergsten et al., 2019]).The first integrative gap, as noted above, is that some ecosystems have more governance mechanisms available than other ecosystems.Given that water is important across ecosystem types, this leaves EAW in some ecosystems weakly governed.Furthermore, one of the premises of multilevel governance theory is that outcomes result from the aggregate governance regime.Thus, in riparian and aquatic ecosystems, the diversity and abundance of mechanisms may compensate for mechanisms (such as prior appropriation) that have a negative impact on EAW.Conversely, in ecosystems with fewer governance mechanisms for EAW, governance mechanisms that negatively influence EAW likely have more deleterious consequences.
The second integrative gap we found is that some agencies may not see EAW as within their scope or mandate even though they govern habitats or species that depend upon having sufficient water.Overall, we found that EAW exists at the margins of most agencies' mandates.
For example, the Montana Climate Change Advisory Committee's Climate Plan focuses on climate change mitigation, not adaptation; their recommendations did not directly relate to EAW or drought.Similarly, despite the U.S. Forest Service's mandate to manage fish and wildlife habitat, including riparian vegetation and instream flow, the Forest Plans we analyzed made few direct references to drought, soil moisture, or ecological uses of water (Table S5).
However, there is growing interest and attention to EAW, ecological drought impacts, and drought planning within the USFS, which presents one opportunity for addressing integrative gaps within this agency.For example, there have been updates to the Custer and Gallatin National Forest plans (FP2 and FP3), which have merged and created the 2020 Land Management Plan since our data analysis was completed.This new FP might pay more explicit attention to drought given the USFS' growing focus on it (U.S. Forest Service, https://www.fs.usda.gov/detail/custe rgall atin/landm anage ment/plann ing/?cid=fsepr d733838).The Forest Service has long recognized the challenge of comprehensively addressing water issues, noting that "forests are not adequately staffed with technical experts to handle the issues related to water that faster than they can be inventoried" (Sedell et al., 2000, p. 15).
Previous literature on integrative gaps emphasizes that failure to address these intersections can lead to inefficient management responses or unintended, negative consequences (Bergsten et al., 2019).However, when integrative gaps are closed, the management system will better reflect underlying ecological processes, making sustainable outcomes more likely (Fried et al., 2022).The complex biophysical interdependencies that directly and indirectly influence EAW require a governance regime that accounts for these interdependencies (Fried et al., 2022).
While "merely establishing a collaborative network does not guarantee successful governance," collaboration may provide one means to address integrative gaps, if collaborative forums serve as venue to improve the fit between institutions and biophysical realities (Bergsten et al., 2019, p. 28).
A first step for closing gaps and improving the governance of EAW would be for agencies to thoroughly assess the scope of their current management responsibilities and the degree to which their actions (directly or indirectly) influence EAW.Second, recognizing that responsibility for EAW is spread across many agencies, greater coordination between agencies, social learning, and other "bridging measures" are needed (Bergsten et al., 2019, fig. 7).Bergsten et al. (2019) found "a reinforcing feedback in which collaboration on common issues creates leverage for more integrative management on those issues, and vice versa, thus amplifying each other" (p.35).The present study did not extensively investigate collaboration, though we did include it as a code in the plan analysis and it was occasionally mentioned by interviewees; we suggest it is a fruitful area for future work.We note that our study sample was organized around one particular collaborative effort, the National Drought Resilience Partnership Montana demonstration project, which we previously found served an important bridging function for ecological drought in the UMH (Cravens, McEvoy, et al., 2021).Other scholars have noted that collaboration can happen formally, between institutional actors, or more informally, based on personal relationships and voluntary actions (Anderson et al., 2016;McNeeley, 2014).
We note that even where governance structures recognize the importance of EAW, maintaining EAW may still be difficult in practice.It is possible that agencies may have the authority to manage EAW, but either do not execute that management well or may choose not to exercise their authority to the fullest extent.During drought or times of water shortage, agencies may choose to prioritize other uses (e.g., traditional and/or human-centered water uses) (O'Donnell, 2018).In such instances, formal governance mechanisms such as the Endangered Species Act and Clean Water Act may serve as necessary levers to incentivize cooperation or prompt action (e.g., Fischman et al., 2021).
In summary, we conclude that while the building blocks for governing EAW exist in the UMH, gaps occur when agencies do not recognize the significant connections between management responsibilities, governance mechanisms, and functions of water on the landscape.At present, governance remains fragmented by political jurisdictions (see Cohen & Davidson, 2011), ecosystem type (e.g., terrestrial vs. aquatic resource management), and focus on particular species (e.g., watershed drought plans that focus on salmonids or wildlife and habitat plans which provide species-specific management guidance).Furthermore, many plans are anthropocentric, focusing on water use for-and by-humans (e.g., reservoir operating plans) or human vulnerabilities (e.g., hazard mitigation plans, drought plans), making EAW especially vulnerable during times of water shortage or frequent drought (Mount et al., 2017).
We attempted to be as comprehensive as possible in our description of the current governance regime, but given its complexity, it is likely that we overlooked some actors and/or mechanisms.We also recognize that new planning documents have been released since the conclusion of our analysis.Furthermore, research aimed at revealing absence (e.g., governance gaps) is particularly difficult (Saunders, 1985).
For example, many watershed plans specifically mention salmonid fishes and their habitat, but the habitat of most other aquatic or terrestrial species was rarely discussed.We interpret the narrow focus of watershed plans on salmonid fishes and lack of attention to these areas as a governance gap.Being able to confidently describe the existence of this gap required describing not only the watershed plan itself but also carefully cataloguing the other actors and governance mechanisms in the watershed.Ideally, an ecologically comprehensive watershed plan would recognize the interdependency between aquatic species, aquatic and riparian habitat, and human uses elsewhere in the watershed that affect water quality and quantity within a river (Dunham et al., 2018;Humphries et al., 2014;Naiman, 1992).Advances in our understanding of EAW suggest the need for an evolution of the existing governance system, towards a system that recognizes the roles and responsibilities for managing EAW across agencies and ecosystem.A governance regime that accounts for these interdependencies is likely to result in more sustainable outcomes.
Despite these challenges, literature on adaptative governance suggests that environmental governance regimes are dynamic and continually evolving (Chaffin et al., 2014;Gosnell et al., 2017).For example, instream flow law has expanded prior appropriation's original understanding of "beneficial use" and continues to evolve (Gillian & Brown, 2013;McEvoy et al., 2018).Planning processes generally require periodic updates to plans, representing an opportunity to reassess their contents and approach.Montana is currently in the process of updating their state drought response plan, which was previously updated in 1995 (DP6).Since that time, there have been new efforts to develop indicators that account for EAW (e.g., Kovach et al., 2019;NOAA, 2022) as well as investments in monitoring that can inform the management of EAW during drought and times of water shortages (e.g., the creation of the Montana Drought Impact Reporter, which encourages local reports of drought impacts to a range of sectors including wildlife, forests and fish, Montana Department of Agriculture, https://agr.mt.gov/Topic s/A-D/Droug ht-Impac t-Repor ter?msclk id=00e44 4cdd0 b711e c9f43 10843 04fa205).More recent planning efforts in the state, such as the 2016 Beaverhead Watershed Drought Resiliency Plan (DP4), provide a more extensive assessment of ecological drought impacts than older watershed drought plans (McEvoy et al., 2018).In addition, drought professionals in Montana are acutely aware of the ecological impacts of drought (Cravens, McEvoy, et al., 2021).Given these advances in drought monitoring and planning, we expect that the updated state plan (that was development at the time of writing) will pay greater attention to EAW.
As Wilhite and Wood (1985) noted, state drought plans create an organizational structure to coordinate the assessment and response of state and Federal agencies.Thus, the state plan update presents an opportunity to address gaps related to EAW by creating a structure that fosters collaboration, integrates across agencies, and bridges diverse mandates.From the Western Governors' Association support of NIDIS (WGA, 2004) to the Obama Administration's NDRP (The White House Archives, 2016), the complex multilevel governance regime for water in the western U.S. has led to calls for bridging entities to collectively address this interconnected challenge.
Recommendations in this report led to the passage of the National Integrated Drought Information System Act of 2006 (NIDIS Act; Public Law 109-430).Responding to the WGA's request for additional assistance following the 2012 drought (NOAA-NIDIS, 2012), the White House established the National Drought Resilience Partnership (NDRP) to further increase BOX 1 Ecologically available water (EAW).
(a) climate plans, (b) drought plans, (c) National Forest plans [federal, USFS], (d) habitat conservation plans [state, location-focused], (e) hazard mitigation plans, (f) reservoir operating plans [water planning], (g) reservoir plans [land use planning], (h) resource management plans [federal, Bureau of Land Management], (i) water plans, (j) watershed restoration plans, (k) wildlife and habitat plans [state, species-focused], (l) National Wildlife Refuge plans [federal].(See Table greater detail, describing their role and scope as it relates to EAW in the Upper Missouri Headwaters basin and listing relevant governance mechanisms used by each agency F I G U R E 2 (a-f) Location of study area, Upper Missouri Headwaters Region, along with the overlap of relevant natural and political boundaries involved in water governance in the study area.Map (a) and Map (b) provide spatial context of the study site.Map (a) shows where Montana lies within the U.S. and in North America.Map (b) shows where the Upper Missouri Headwaters Region is located within the state of Montana.Map (c) delineates the eight subbasins (HUC 8 size; Several cross-cutting governance mechanisms may indirectly affect EAW in all or multiple ecosystems, either via encouraging reductions in human water consumption (HMP, WP, WSP) or as a result of water storage decisions that take into account ecological health (DP4, NEPA, WP, WRP).Other governance mechanisms (ESA, RMP, WH2) manage broadly for species health, with the ability to affect various ecosystems, depending on the species.Governance mechanisms that manage ecologically available water and governance mechanisms that create governance gaps, organized by ecosystem type and main focus within the ecosystem.Governance mechanisms are categorized as laws, plans, or administrative policies, programs, and permits."310Permits",Montana's Natural Streambed and Land Preservation Act; CWA, Clean Water Act; DP, Drought Plan; FERC, Federal Energy Regulatory Commission; FP, Forest Plan; HCP, Habitat Conservation Plan; HMP, Hazard Mitigation Plan; RMP, Resource Management Plan; ROP, Reservoir Operating Plan; RP, Reservoir Plan; WHP, Wildlife & Habitat Plan; WP, Water Plan; WRP, Wildlife Refuge Plan; WSP, Watershed Restoration Plan.See TableS6for details of how mechanisms were classified.
F I G U R E 5