Water Quality Improvement Project
Lake Loma Area:
Total Phosphorus


Lake Loma is a 23-acre lake located in the Seven Lakes area, north of the Tulalip Reservation in western Washington State. The Seven Lakes form three separate drainage basins: (1) Lake Martha Watershed and Howard Lake drain northwest to Port Susan; (2) Lake Ki drains to the Stillaguamish River; (3) Lake Loma is the first in the chain of the four lakes which include Crabapple, Goodwin and Shoecraft. These lakes eventually drain west into Tulalip Bay. (See Study Area map)

Water quality issues

Since the mid-1980s water quality studies have shown that conditions in Lake Loma have steadily declined. The lake has a maximum depth of 28 feet and an average depth of 11 feet. Water clarity is low and algal blooms are consistently present in the summer months. According to the Snohomish County Surface Water Management’s (SWMM) 2012 State of the Lakes Report, Lake Loma is one of the most developed lakes in the county. There are approximately 58 homes and 52 docks on the lake, encompassing 0.35 acres of shoreline. Lake Loma has about one mile of shoreline with 16 percent having some type structure, such as a bulkhead or barricade separating the lake from land. Only 45 percent of Lake Loma’s natural shoreline remains intact. Lake Loma is currently on the 2008 303(d) list of polluted waterbodies for total phosphorus.

Loma Lake, Washington State.  Photograph courtesy of Tricia Shoblom, WA Department of Ecology.


Why this matters

Excessive amounts of phosphorus can be detrimental to Lake Loma’s water quality and beneficial uses. High levels of phosphorus can cause excessive plant and algae growth, which in turn may have unfavorable impacts to water clarity, aquatic habitat, fish survival, swimming, boating, aesthetic enjoyment, and human health.

Status of the project

Ecology is developing a straight to implementation (STI) project to determine the source(s) of phosphorus pollution and develop a strategy to bring Lake Loma back in to water quality standards.


Technical information

Lake Loma Phosphorus Screening-Level Assessment

Snohomish County State of the Lakes Report

Related information

WRIA 7: Snohomish Watershed Information (Environmental Assessment Program website)

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Last updated May 2015
  Water Resource Inventory Area (WRIA) 7 map, Washington State.


WRIA: #7 (Snohomish)
County: Snohomish

Water-body Name:
Lake Loma

Total Phosphorus

Status: Under development as a straight to implementation project

Contact Info:
Tricia Shoblom
Phone: 425-649-7288
Email: Tricia.Shoblom@ecy.wa.gov

Northwest Region
Department of Ecology
3190 160th Ave. SE
Bellevue, WA 98008-5452