**1. Introduction**

Annual course closures in the U.S. have exceeded new course openings since 2006. On average, 0.8 percent of the total supply in 18-hole equivalents has closed over the last 30 years, increasing to as high as 2.1 percent immediately prior to COVID-19 [1]. Closed golf courses are mostly repurposed for residential and commercial real estate but some are converted for agricultural or recreational uses. Because of the large areas of open space they comprise, closed golf courses provide an unmatched opportunity to maximize the ecosystem services they provide [2]. In a national study of golf course closures across the United States, Cederberg [2] found that 42 percent of the closed courses examined had no clear plans for future use. Of the courses that

had been converted to parks and open spaces, the results indicated that large areas of former courses were converted to open spaces or natural areas with services limited to trail walking, nature viewing, and outdoor education [2].

Since Petrosillo et al. [3]. make the case that urban planners consider early in the planning phase the ecosystem services that new golf courses may provide, it is equally, if not more, important in planning for course closures. Particularly with respect to publicly owned courses facing closure, leaders need to consider whether a closed golf course can support critical ecosystem services beyond cultural services associated with health, well-being, and education. Golf courses account for as much as 29 percent of all urban greenspace and are the most accessible form of greenspace for approximately 3.4 percent of the U.S. urban population [4]. Course closures, by virtue of their extent alone, provide a unique opportunity to integrate those services with others that more directly address current and future challenges that face a community (e.g., water regulation in the case of communities with combined sewer overflows or climate amelioration in urban heat islands).

In the upper Great and Little Miami River watersheds, comprising an area of approximately 8000 km2 , of the 53 golf courses identified, nine have closed since 2012. One of these courses was converted for residential use and another for agricultural use, but the remaining seven are green spaces, mostly fallow since the time of closure. Only one of them (the former Larch Tree Golf Course west of Dayton, Ohio) was assessed for its conservation value and converted into a wetland mitigation bank. In addition to trails, wildlife, and educational opportunities, the former course provides wetland habitat and improves water quality, regulates runoff, and reduces erosion in addition to the host of other regulating and supporting services. Another one of the closed courses, the former Snyder Park Golf Course (SPGS), an 18-hole municipal course in Springfield, OH, is the subject of this study. It was closed in 2014 without a post-closure plan.

The goal of this chapter is to provide an example of how a select ecosystem service can be assessed to maximize the sustainable reuse of a golf course. The former golf course could provide a number of ecosystem services, including provisioning services (food, fresh water, fiber, and fuel), regulating services (climate regulation, water regulation, erosion control, water purification, and pollination), cultural services (education, recreation, and tourism), and supporting services (soil formation, nutrient cycling, and primary production) [5]. The focus of this study is on the role the former golf course plays in water regulation. Two different processes are associated with water regulation, flood prevention, associated with runoff generation occurring at the watershed scale, and flood mitigation, associated with storage of water once it has accumulated in the stream [6]. In cases of prevention, the need for vegetation biomass and forest to prevent runoff is critical, whereas available storage space for stormflow along the stream corridor is critical for mitigation [6]. In this study, I examine the stormflow conditions under which the former course floods, the surface water-groundwater interaction during flooding, and the volume of flood storage it provides.

### **2. Study area**

Snyder Park Golf Course opened in 1920 as an 18-hole public golf course operated by the City of Springfield and National Trail Parks and Recreation District. The original course was constructed on the floodplain at the confluence of Mad River and
