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ASLESON, NESTINGEN, GULLIVER, HOZALSKI, AND NIEEIER SITE SELECTION AND DESCRIPTIONS Twelve sites in Minnesota were selected for the development and evaluation of the rain garden assessment during the 2006 field season (spring through fall). These sites were selected based on the following criteria: (1) permission and participation from the owner /operator of the site, (2) availability of site information (e.g., site plans, planting diagrams, etc.), and (3) proximity to the University of Minne- sota (UM). A summary of the rain garden character- istics and the levels of assessment used at each site are provided in Table 1. The areas of the rain gardens ranged from 28 to 1,350 m The smallest rain garden was located in a residential area and received stormwater runoff from the street via a curb cut inlet. Several other rain gardens received runoff from parking lot areas, or a combination of stormwater runoff sources. Three rain gardens were installed in the fall of 2003 and were online (i.e., receiving runoff) in the spring of 2004. Only the UM — Duluth (12) site had a pretreatment practice installed, a sediment forebay located at the inlet. Four of the rain gardens contained underdrains to compensate for the restrictive soils in the area. METHODS AND ANALYSIS Visual Inspection The rain gardens were examined for obvious drain- age problems or impediments to infiltration, such as ponded water present for more than 48 h after a rain- fall event, sediment accumulation in the basin from the drainage area, clogged inlet or outlet structures, and excessive erosion within the rain garden. The vegetation was then assessed with consideration of the age of the :rain garden, time of the growing sea- son, species present and their growth requirements, and condition of the site. A visual assessment of the health of the plants was made by examining and recording the color, size, and quality of the leaves, stem, and flowers. The available design plans along with a plant field guide (Shaw and Schmidt, 2003) were used to determine whether the correct species were present. The percent vegetative cover was esti- mated to determine if plants were established. The sites were also inspected for the presence of wetland plant species (e.g., cattail, arrowheads, and marsh smartweed) to determine if hydric soils may be pres- ent, indicating prolonged periods of saturation. Photo- graphs of each site were taken and observations made were recorded to develop a complete record of conditions at the time of assessment. The depth at which rain gardens are installed var- ies greatly and is dependant on local factors such as drainage area, surface area available for the rain gar- den, and underlying native soil type. To determine the existing soil profile a single soil core was taken at each rain garden near the center of the basin (as a representative sample) to a depth of —1.2 m. This was the maximum depth a standard auger could pen- etrate using a soil corer and was believed to be suffi- cient to profile the near - surface soils that are important to infiltration. The textures of the different soil layers in the core were determined in the field using the feel method (Thien, 1979) and the USDA Textural Triangle. The color of the soil from each distinct layer in the core was determined by match- ing with a color chip in a Munsell soil -color charts (X -Rite, Grand Rapids, Michigan). Special attention was paid to soils that were gray in color or contain TABLE 1. General Description of the Assessed Rair. Gardens ID Rain Garden Name Size (m Level of Assessment Year Built Source of Urban Runoff 1 Burnsville 28 1 and 2 2003 Residential street 2 RWMWD #4 29 1 and 2 2006 City street and office building roof A' 46 1 1999 Parking lot and turf 3 B' 50 1 2001 Residential street 4 5 RWMWD #5 59 1, 2, and 3 2006 City street and office building roof 6 UM — St. Paul 67 1, 2, and 3 2004 Turf and street 7 Cottage Grove 70 1, 2, and 3 2002 Parking lot 8 C 1 140 1 2001 Residential street 9 RWMWD #1 147 1 and 2 2006 City street and office building roof D 180 1 2001 Residential street 10 11 Thompson Lake 278 1 and 2 2003 Parking lot 12 UM — Duluth 1,350 1 and 2 2005 Parking lot Notes: RWMWD, Ramsey - Washington Metro Watershed District; UM, University of Minnesota 'Permission to publish the locale of these sites was not obtained. JAWRA 1022 JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION