Rain-Garden Design & Maintenance – Lee R. Skabelund (2012) Project Team: Lee R. Skabelund, Project Coordinator and Co-Designer Cary Thomsen, MLA Student (Spring 2007), LAR Dept. – Co-Designer Dennis Day, Professor LAR Dept. - Construction Advisor; Level-Spreader Designer Mark Taussig, Interim Assoc. Director, KSU Facilities – Project Approvals Jackie Toburen, Physical Plant Supervisor, KSU Facilities & Grounds – Project Support Client: KSU International Student Center (ISC) Project Name/Location: KSU ISC Rain-Garden; Manhattan, Kansas Project Completion (Construction): June 2007 (gardens and pathways) May 2008 (rain-bowls) Existing Land Use Type: Existing urban development (turf grass to garden; pipe to non-pipe) Project Type: Campus Design, Construction & Maintenance Issues Addressed by the KSU-ISC Rain-Garden Helps restore and reveal the natural hydrologic cycle by collecting rooftop runoff in an aesthetically pleasing manner between the Taiwan Wing of the Kansas State University International Student Center (ISC) and Campus Creek (a tributary of the Kansas River). Demonstrates (to KSU administrators, campus facilities/grounds personnel, KSU faculty and students, and a wide range of visitors) how rooftop water can be readily collected and re-used to nourish a perennial garden consisting of plants native to the Flint Hills Eco-region and Central United States while responding to the unique characteristics of the site and adjacent architecture. Re-uses leftover (salvaged and donated) limestone from a local stone company. Demonstrates the creative use of permeable pavers (using salvaged cut stone and native flagstone) and a level- spreader – to slow, temporarily hold, and infiltrate stormwater runoff falling on or entering the rain-garden. Addresses important aesthetic desires by the client (KSU Facilities) and visitors, connecting the garden to the eight-foot grid of the adjacent ISC buildings and courtyard. The project is part of a larger vision for creating a more sustainable campus at Kansas State University – with water conservation, stormwater management, and energy efficiency as primary drivers of proposed activities. In October 2006, over 125 students, faculty, staff, and professionals participated in a stormwater management planning/design charrette that helped kick-start this design-build demonstration project. The KSU ISC Rain-Garden (the first rain-garden in the community) has created tremendous excitement on campus about the prospect for retrofitting poorly designed and water-and-energy- intensive buildings and landscapes, and creating a more sustainable campus environment. With a grant of $5,000, the rain-garden was constructed employing all volunteer labor (more than 60 KSU faculty, staff, and students assisted) and rented or donated tools and equipment. Local contractors and businesses donated time and equipment to haul and stone to the site. Most plants were purchased; some were donated. Other materials were purchased or donated as needed to meet design intentions and reduce costs. ISC staff and KSU students were invited to temporarily water and help weed the rain-garden (as volunteers and/or for extra credit). Staff from KSU Facilities & Grounds staff are assisting with maintenance and weed control and desire to see additional water-sensitive design projects implemented on campus. Monitoring Data Visual observations indicate that the rain-garden collects and infiltrates all precipitation falling on the Taiwan Wing, the rain-garden, and the garden’s “watershed” for most storm events less than 1-1/2 to 2 inches. Monitoring of vegetative health is ongoing as plantings were completed in late April, May, and June of 2007. The rain-garden is used to educate KSU students and other visitors about the importance of ongoing site/rain-garden maintenance and monitoring. Four soil density probes and four infiltration tests were completed in April 2008 and provide an idea of soil conditions within and immediately down slope of the KSU ISC rain-garden. Infiltration tests indicated rates of 0.62 to 14.10 cm/hr (with the highest rate recorded directly over one of the native forbs planted as a 4-inch container plant). Soils are very heavy clay with bulk densities of 1.05 g/cm^3 to 1.29 g/cm^3. Additional infiltration testing may be done in the coming years to see how quickly water infiltrates into the rain-garden. Bulk density tests will may also be done to see if densities decrease over time (which should occur if compaction/foot traffic is minimized and as the native grasses and forbs mature). Ongoing monitoring will help the project team learn which plants are best suited for the particular site conditions and show how infiltration rates and soil densities change over time, thus providing important information for future rain-garden and bio-retention designs within the Flint Hills Eco-region. Project Costs Spring and Summer 2007 expenditures for the project were $4,982.86, and were covered by a Campus Compact WaterLINK grant. Not including volunteer time by KSU faculty and students, total donations from external partners and non-academic departments during Spring and Summer 2007 were estimated to be approximately $7,800. Hundreds of hours of donated time were also provided. Financial support for a small portion of the time provided by the two co-designers came from a USEPA/KDHE grant, noted below. KDHE provided financial assistance to the KSU ISC Rain-Garden Project through EPA Section 319 Nonpoint Source Pollution Control Grant #C9007405-12. Three WaterLINK (Water Quality Restoration and Protection Service Learning Mini-Grants awarded to KSU by KDHE utilizing EPA funds) provided financial assistance for the Fall 2006 KSU Campus Creek Planning/Design Charrette, Spring & Summer 2007 ISC Rain-Garden construction for the KSU ISC Rain-Garden. Maintenance and Management Strategies Staff members from KSU-Grounds assist with maintenance and weed control in collaboration with Landscape Architecture Department faculty and students and other student volunteers. Maintenance costs are modest (low), however, the time spent to care for the garden is typically greater (than the time it would take to simply run a mower across a similar sized lawn). Spot treatment of weeds using herbicides were selectively used to keep invasive grasses of the rain-garden in check during the first growing season. Future treatments using chemicals are deemed unnecessary. Shredded hardwood mulch was used to minimize the growth of weeds and make weeding easy to perform during the first two years but leaves from the American Sycamore and decaying plant material in the garden now make mulching unnecessary. Challenges and Unique Constraints Weed species transported by birds and wind are the major maintenance challenge. We knew this going in and so we decided to place weed barrier beneath our porous pathways on the north and south sides of the rain-garden. Weeding is the common lot of gardeners! Making time to regularly monitor and weed (before weeds go to seed) is essential. Plan to budget at least a few hours a week during the first growing season to monitor and maintain (especially watering and weeding) your rain-garden; it will save you loads of time down the road! This was the first rain-garden designed and implemented on campus or within the city and so we did not have any local models to learn from. We drew upon ideas from across the country (including award-winning projects posted at www.asla.org, and from Topeka (especially Jackson Stree), Lenexa, and Kansas City (especially The Discovery Center). KSU-Grounds staff members were initially skeptical about the ability of the very heavy clay soils to properly infiltrate water. However, after breaking up the soil and getting plants established (which only took two months in 2007) the soil readily infiltrates, and plants evapo- transpire stormwater runoff quite rapidly. After large storm events we rarely see stormwater in the basins for more than a few hours and rarely see water in the upper, wetter basin for more than a day. Mosquitoes typically need 4-5 days to breed and hatch so properly functioning rain- gardens do not contribute to producing theses pesky insects. The project relied heavily on donated time, equipment, tools, and labor and took many, many hours to effectively coordinate. The rain-gardens at Sunset Zoo (2009 and 2011 projects) were also a lot of work, but we think it is well worth the effort to move from eroded grass and underutilized asphalt parking and concrete sidewalks to a series of pocket rain-gardens and terraces. ISC staff love both perennial garden and their dynamic presence through the seasons! Lessons Learned Persistence is required to create initial demonstration projects on a campus or in a community. Interest in energy and water savings opens the door for creative, multi-benefit projects that create more sustainable landscape structure and functions. Deep-rooted prairie plants and small-scale rain-gardens can make an immediate impact on stormwater runoff. When carried out in an integrated and holistic manner – especially as usable garden spaces – even very small scale projects can make a very important and positive impact. Any garden requires dedicated maintenance. Weeding is essential. Fertilizing is not needed if native plants adapted to the location are used. Pruning is rarely needed, though clipping back perennials before spring is important. Watering during the first growing season is vital Building institutional interest and capacity for ongoing maintenance is essential. Universities, colleges, and other educational institutions can play an important role in assisting local communities monitor sites, helping them and others build increased understanding about the sustainability of specific planning, design, and construction practices. Key Ideas to Remember in regards to Maintenance: 1) Rain-Gardens need to be maintained (there is no free lunch when it comes to maintaining gardens and created or disrupted landscapes). 2) Weeding is essential (although a good hardwood mulch can reduce the number of weeds and make weeding easier). Fertilizing is not needed if you use plants adapted to the region and site.