BUREAU OF ENVIRONMENTAL SERVICES • CITY OF PORTLAND YEAR Portland Area Watershed Monitoring and Assessment Program Executive Summary–First Year Data 1 Nick Fish, Commissioner Michael Jordan, Director OCTOBER 2015 EXECUTIVE Portland Area Watershed Monitoring and Assessment Program SUMMARY FIRST YEAR DATA (FY 2010-2011) PAWMAP gathers and The Portland Area Watershed Monitoring and Assessment Program analyzes data from these Portland-area watersheds: (PAWMAP) redesigned the city’s watershed monitoring to more • Columbia Slough directly support the 2005 Portland Watershed Management Plan. • Fanno Creek The program: • Johnson Creek • Coordinates and integrates watershed monitoring across all watersheds, to make results comparable. • Tryon Creek • Collects all watershed measures at the same locations to support more • Tualatin River powerful analysis of patterns in the data. • Willamette River • Uses a strong statistical design that increases the accuracy and efficiency of tributaries only data collection. • Adopts an approach designed by national monitoring experts, providing information that is directly comparable to state and federal monitoring efforts. • Supports regulatory compliance requirements under the Clean Water Act and the Endangered Species Act. Portland watersheds are very diverse, including steep Forest Park streams, moderate-gradient streams like Tryon and Johnson creeks, and low-gradient waterbodies like the Columbia Slough and Columbia and Willamette Rivers. Stream sizes range from small seasonal streams to the fourth largest river in the country. Land cover ranges from the heavily forested Forest Park and Tryon Creek State Natural Area to the highly industrialized Portland Harbor. PAWMAP samples the habitat, water quality and biological communities of Portland’s watersheds1. This document summarizes the results of the first year data sampling in each watershed. TERMS AND DEFINITIONS Please refer to the Glossary starting on page 16 for definitions of the technical terms used throughout this summary. 1 Monitoring in the major rivers—the Columbia and Willamette—has not been incorporated into PAWMAP yet due to the large amount of existing information and complexity of issues in Portland Harbor. Developing the approach for incorporating large river monitoring into PAWMAP is in progress. EXECUTIVE SUMMARY: Portland Area Watershed Monitoring and Assessment Program 2 Report on First Year Data (FY 2010-2011) Portland area watersheds with first year sampling sites In the first sampling season (July 2010 – June 2011) BES Field Operations staff monitored 20 sites along perennial streams and 12 sites along intermittent streams. First Year Sampling Sites Perennial Watershed Boundary Intermittent Portland City Limits C O L U M B I A R I V E R 0121 TLAND0329 RD N. POR 0017 0105 WILL AIRPOR COLUMBIA BL T WA AMET VD 0345 VD 0273 Y T E R I V E R Columbia Slough MLK JR. BL WATERSHED 0137 0129 0078 0506 0080 0298 0014 0250 0378 0122 BURNSIDE Tualatin 0186 Willamette River River WATERSHED WATERSHED POWELL 0314 Johnson Creek WATERSHED 0636 0272 0188 0124 0426 0012 0524 McLOUGHLIN Fanno Creek 0058 0060 0016 WATERSHED 0352 0476 0208 SIMPLIFIED MAP. NOT TO SCALE 0144 WS 1311 JULY 2013 Tryon Creek WATERSHED TERMS AND DEFINITIONS Intermittent: Streams which typically do not flow year- round and lack flow during the dry summer months. Perennial: Streams which typically have water flowing year round. City of Portland Bureau of Environmental Services 3 October 2015 Summary of First Year Sampling by Watershed This Columbia Slough site (0129) is an example of a typical slough site. The slough is a naturally low-gradient, slow-flowing system which is very different from the other streams in Portland. WATERSHED: COLUMBIA SLOUGH The Columbia Slough begins at Fairview Lake and meanders west for 19 miles to Kelley Point Park where it empties into the Willamette River. Historically, the Columbia Slough waterway was a low-gradient collection of wetlands, lakes and streams that formed the Columbia and Willamette river floodplains. The slough is Portland’s most altered watershed and waterway. Over the years, the area was heavily altered to accommodate industry, transportation and agriculture. Beginning in 1918, levees were built to provide flood protection. Wetlands and side channels were drained and filled to allow for development. The waterway was channelized, and dozens of streams were filled or diverted to underground pipes. Field staff measuring a common carp, a non-native fish species common in the Columbia Slough. Non-native fish are abundant in the Columbia Slough. While most Portland streams typically have less than 1% non-native fish The Columbia Slough at Whitaker Slough (site 0273) comprising their fish communities, is an example of a “boatable” survey site, where deep the Columbia Slough has well water does not allow field staff to traverse the stream over 35% non-native fish in its fish safely and sampling must be done from a boat. communities. EXECUTIVE SUMMARY: Portland Area Watershed Monitoring and Assessment Program 4 Report on First Year Data (FY 2010-2011) First year data summary—Columbia Slough HABITAT WATER QUALITY BIOLOGICAL WOOD TEMPERATURE2 AQUATIC INSECTS Like most Portland watersheds, large Most of the stations sampled in the first year exceeded The Columbia Slough had the lowest wood is very scarce, in part because of temperature standards until fall. The one exception aquatic insect community scores of limited riparian vegetation and the need was Whitaker Slough, which never exceeded standards all the watersheds. It is important to maintain flood control capacity. after the probes were placed in mid-July. to note, however, that most metrics used to evaluate the health of aquatic EUTROPHICATION insect communities are developed for pool-riffle stream systems. They The Columbia Slough is one of the few watersheds are not as effective in addressing in which signs of eutrophication – excessive low gradient systems like the slough. nutrients that lead to overproduction of algae and Poor aquatic insect communities in low dissolved oxygen – are present. The slough is the slough are likely a result of two naturally susceptible due to low gradient, slow flows factors: macroinvertebrate metrics are and long residence times, but human alterations not designed for slough systems and including removal of wetlands that process nutrients, watershed conditions are also poor. segmentation by culverts, and discharges that increase nutrient loads have created the problem. SUBSTRATE TOTAL SUSPENDED SOLIDS FISH The Columbia Slough substrates are The slough had the highest median TSS of all the Fish communities are dominated by naturally fine grained due to its low watersheds, but maximum TSS values were not as high invasive species in the slough whereas gradient, slow flows and floodplain as some other watersheds (e.g., Willamette Streams, they are a minor component in other deposits. Johnson Creek). The slough tended to have higher TSS watersheds. While the most abundant than other watersheds during the seasonal (non-storm) species was the native three-spined sampling, but lower values during storms because of stickleback, six of the ten most abundant lower gradients and less flashy flows. species were non-native. E. COLI The slough was tied with the Willamette Streams for lowest overall median E. coli concentration (20 MPN), and had only one measurement above the single sample criterion of 406 MPN, the lowest of any watershed. RIPARIAN CONDITIONS METALS RIPARIAN BIRDS The levee system precludes the presence The slough had moderate levels in comparison to Riparian bird communities typically of riparian vegetation along many parts other watersheds for zinc and lead, and low values for had low integrity in the slough. This of the slough, and this is reflected in copper and mercury. The slough was one of the only was likely due to the low percentage of percentages of riparian canopy far below watersheds that did not have at least one exceedence riparian canopy, which was an important the other watersheds. of the copper criterion during storm flows. determinant of bird community health. However, a site in the Upper Slough PORTLAND WATER QUALITY INDEX near Big Four Corners had the highest number of Special Status and At-Risk Three of the five stations sampled in the first year bird species (7 species) of all the first year were above the PWQI Properly Functioning Condition sites. benchmark of 60. One station in the upper slough had a PWQI of 50 and in Elrod Slough had a PWQI of 34. 2 Because of the time required to secure access to sample stream reaches through private property, temperature probes were often not installed until mid- late-summer. This will be an issue in sampling the four rotating panels for the first time, but since access permissions have been acquired, will not be an issue for the second and subsequent rounds of sampling each panel. City of Portland Bureau of Environmental Services 5 October 2015 Summary of First Year Sampling by Watershed Riparian vegetation sampling location #0058 in Woods Creek includes western red cedar, vine maple and sword fern. WATERSHED: FANNO CREEK Fanno Creek is one of a series of streams that drain the west slope of the Tualatin Mountains to the Tualatin River, then flow to the Willamette River above Willamette Falls. Fanno Creek is a tributary to the Tualatin River Basin, which drains about 20,500 acres. Of that land area, 4,528 acres are within the City of Portland jurisdiction. Land use in the Fanno Creek Watershed is dominated by residential, industrial, and commercial activities. Above: Water quality is sampled quarterly on the Fanno mainstem to capture seasonal changes, and once during storm flows at each site. Stormwater can be a major threat to the health of urban watersheds, and sampling during storm flows helps to understand how stormwater affects stream health. Left: Fanno Creek sampling location #0314 is adjacent to the Beaverton- Hillsdale Highway. Culverts are common along urban streams and have major impacts. They can limit the ability of fish to move between different habitats seasonally, impact water quality, and alter natural stream flows.