City of Modesto - Secondary Wastewater Treatment Facility
City of Modesto - Secondary Wastewater Treatment Facility
ACCESS UPDATE: As of 7/9/2025: DUE TO ONGOING CONSTRUCTION THE PONDS ARE CLOSED UNTIL FURTHER NOTICE.
ACCESS PROCESS: To request access, birders must contact the Facility no later than the Monday preceding Public Access Day using the birdwatching@modestogov.com email address.
**When you arrive onsite, please call the senior operator (209) 652-8662 for access onto the plant. Be sure to ask the operator which entrance thay prefer to meet you at. It is often the northern entrance (no stoplight). Please sign in and out in the Admin Building.
July: Sunday 13th & 27th
August: Sunday 10th & 24th
September: Sunday 14th 7 28th
October: Sunday 12th & 26th
November: Sunday 9th & 23rd
December: Sunday 14th & 28th
DIRECTIONS: This wastewater treatment plant is located at 7007 Jennings Road in southwest Stanislaus County.
From downtown Modesto, drive on H Street for 2.7 miles until you get to Carpenter Road. Make a left (south) and go for 3.5 miles until you come to Keyes Road [J16]. Turn right (west) for 1.9 miles until you come to Jennings Road. Make a left on Jennings Road and go south for 2.0 miles until you arrive at the closed entrance gate.
Assuming you have received permission, you may call the plant operator with the number you have been given. A worker will be at the gate shortly to let you in. You must sign in at the main office, sign a liability waiver form, and obtain a map that shows which ponds you are permitted to visit. Be careful to observe the “off limits” portions of the ponds, which are marked by signs prohibiting birding past that point. When you finish your tour, you must sign out. There is no help needed for exiting the facility. Just turn right past the composting area to continue to the exit gate.
HABITAT: The plant itself features large storage and circulation ponds bordered by graveled levee roads. Along the west side of the storage facility, there is an edge of good riparian habitat featuring a mix of cottonwood, willow, button willow, and box elder. The riparian habitat, though not birded nearly often enough, has produced two records for Indigo Bunting. Currently the riparian area cannot be entered, but you may still scan the area with binoculars and/or scope from the levee for birds. During spring and fall, this area features good numbers of passerine migrants, as well. California Thrashers, formerly common among the extensive areas of Atriplex, have become harder to find since most of the Atriplex plants were eradicated. The ponds and levees have featured all of the expected Central Valley wintering and resident waterfowl. The ponds and levee roads also attracts all of the expected species of gulls and shorebirds.
BIRDS: Pied-billed and Eared Grebe, American White Pelican, Double-crested Cormorant, Great and Snowy Egrets, White-faced Ibis, Canada Goose, Gadwall, American Wigeon, Mallard, Cinnamon Teal, Northern Shoveler, Green-winged Teal, Canvasback, Redhead, Ring-necked Duck, Lesser Scaup, Ruddy Duck, Northern Harrier, Red-tailed Hawk, Swainson’s Hawk, Peregrine Falcon, American Coot, Black-bellied Plover, Killdeer, Greater and Lesser Yellowlegs, Least and Western Sandpipers, Wilson’s and Red-necked Phalaropes; Ring-billed, California, and Herring Gulls; Forster’s and Black Terns, Tree and Cliff Swallows, Lazuli Bunting, Red-winged Blackbird, Blue Grosbeak.
RARE AND UNCOMMON BIRDS: The ponds have been a fairly reliable location to see Pacific Golden-Plover, often mixed in with Black-bellied Plovers. Other birds that are occasionally seen are Tundra Swan, Mew Gull, Semipalmated and Snowy Plovers, Willet, Marbled Godwit, Ruddy Turnstone, Sanderling, Bank Swallow, and Swamp Sparrow.
Uncommon to rare waterfowl have included Long-tailed Duck, Surf Scoter, Brant, Tufted Duck, and Eurasian Wigeon, mostly in winter. Rare shorebird records have included Black Turnstone, Red Knot, Wandering Tattler, Red Phalarope, American Golden Plover, as well as Baird's, Pectoral, Stilt, and Solitary Sandpipers. Uncommon gulls found there are Western, Thayer’s, and Glaucous. Rare gull records include one record each for Little Gull and Laughing Gull, and several records for both Franklin’s and Sabine’s Gulls. There are also single records for Long-tailed and Parasitic Jaeger. There are several records for Common Tern, one record for Least Tern, and one record for Arctic Tern. Most of the records for these ponds were documented when the ponds were open to the general public throughout the week. Though access is now restricted, almost anything is possible at this location almost any time. For example, the Little Gull was photographed on May 25, 2006, an unexpected but not uncorroborated date.