Origin of the Cole Creek Levee

Background: Flooding in Big Valley and Early Flood Control Efforts

The Big Valley area near Kelseyville (including Green Acres and Soda Bay) has a history of flooding. Tributary streams like Manning, Adobe, Kelsey, and Cole Creeks drain the southern and southwestern shores of Clear Lake, and severe floods in 1955 and 1958 caused significant property damage in Kelseyville, all around Lake County, as well as in neighboring counties.

In response, local authorities sought to reduce flood risk by channelizing and leveeing these creeks in the mid-20th century. Indeed, many Clear Lake tributaries were straightened, deepened, and bounded by levees during the 1950s–1960s as a flood mitigation measure. This trend was not unique to Cole Creek – for example, nearby Kelsey Creek through Kelseyville was substantially modified by the mid-1960s (deepened by ~10 feet, with bank stabilization and straightening) to confine its flow. Formerly, Kelsey Creek had a shallow, braided channel up to 1,500 feet wide that frequently overflowed; the 1960s channelization greatly reduced such flooding around town. These projects, however, also had environmental costs (e.g. loss of riparian habitat and impaired fish passage).

The Cole Creek Levee’s Construction (Circa 1958–1959)

In the specific case of Cole Creek, U.S. Geological Survey maps indicate that the creek’s course in the Green Acres/Soda Bay area was straightened and a levee appeared sometime between 1958 and 1959 (the levee runs along the engineered channel just upstream of the Clark Drive bridge). This timing strongly suggests the levee was built in direct response to the 1955 and 1958 floods.

While detailed construction records have proven elusive, the absence of any federally authorized project for Cole Creek in that era points to a local initiative. The Lake County Flood Control and Water Conservation District, established in the 1950s, was likely the lead agency. Contemporary studies and reports hint at local and state collaboration: for example, a 1970s ecological assessment notes that flood-control channelization of Clear Lake tributaries was carried out to protect farms and homes. A consultant’s report in the late 1960s (by George S. Nolte & Associates) was prepared for the Lake County Flood Control District and the Big Valley Soil Conservation District (with state/federal assistance), indicating that local soil conservation authorities and the State may have been involved in planning improvements in Big Valley. It appears that landowners and local government, possibly with state aid, constructed the Cole Creek levee in the late 1950s to contain the creek’s flow within a fixed channel and thereby shield adjacent properties from frequent inundation.

Was the U.S. Army Corps of Engineers Involved?

There is a local rumor that the Cole Creek levee was built by the U.S. Army Corps of Engineers (USACE). However, available evidence does not support a direct Corps role in Cole Creek’s project. It’s important to note that the Army Corps was active in Lake County in that era – but on a different project: the Middle Creek Flood Control Project near Upper Lake (north of Clear Lake). Congress authorized that project in 1954, and the Corps constructed a system of levees and a diversion channel on Middle, Scotts, and Clover Creeks beginning in 1958. (For instance, a levee along Rodman Slough at the north end of Clear Lake – built atop earlier reclamation dikes – was finished by the Corps in 1959.) Those federally-built levees are in the Upper Lake region, not near Kelseyville. In contrast, Cole Creek in Big Valley was not part of any federally authorized flood-control project. The Army Corps’ Sacramento District did produce a 1974 Flood Plain Information report for “Big Valley Streams (Manning, Adobe, Kelsey, and Cole Creeks)”, but that was a technical study to assist local planning, not a construction project. Nowhere in that report (nor in Corps civil works histories) is there mention of a USACE-built levee on Cole Creek. In fact, modern Corps databases treat the Cole Creek levee as a non-federal local levee: the National Levee Database entry for “Lake County Levee 4” (a 0.46-mile levee along Cole Creek at Soda Bay) has no listed construction date or federal project number, indicating it was not built under a Corps civil works program. Lake County officials have likewise implied that after mid-century channel improvements were made, maintenance of Cole Creek fell to local authorities – unlike the Middle Creek levees which had ongoing state/Federal involvement.

In summary, the rumor that the Army Corps “built the Cole Creek levee” appears to be misplaced. It likely arose by association with the Corps’ 1958–1960 Middle Creek project or from the general fact that many creeks were channelized in that period. Primary sources and official records point to the Lake County Flood Control District (and possibly the Big Valley SCD/State) as the entities responsible for straightening Cole Creek and constructing its earthen levee in 1958–59, not the U.S. Army Corps of Engineers. This local project was undertaken to alleviate chronic flooding in the Green Acres/Soda Bay community, by confining Cole Creek to a new straight channel with a levee to contain high flows. There is no record of federal authorization or funding for Cole Creek’s levee – all evidence indicates it was a local/state initiative, with the Army Corps’ role limited to later advisory studies and inspections.

Supporting Evidence

• Flood History & Channelization: By the early 1970s, studies noted that many Big Valley creeks were channelized and leveed in response to frequent flooding in the 1950s–60s. Major floods in 1955 and 1958 had inundated the Kelseyville area, prompting calls for flood control measures. Cole Creek’s realignment and levee date to this post-1958 period (the USGS Kelseyville topo map was updated by 1959 to show the new straightened channel).
• No Corps Project Authorization: The Middle Creek Project (Upper Lake) was the only Lake County flood-control work built by the Corps in that era (authorized 1954, built 1958–1966). Cole Creek is geographically separate and was not included in that federal project. The Army Corps’ 1974 report on Big Valley streams treats the Cole Creek levee as an existing condition, not as a Corps-constructed feature.
• Local Agency Responsibility: Lake County documents and environmental analyses consistently describe the Cole Creek levee as part of the local flood infrastructure. For example, a biological assessment in 2012 explains that Scotts, Middle, Clover (Upper Lake) were straightened and leveed with federal involvement, whereas Big Valley’s creeks (like Cole) were locally channelized to protect farms and homes. Modern inspections by the Corps list the Soda Bay/Cole Creek levee in the National Levee Database without a construction year, implying no federal record. Maintenance and improvements (or lack thereof) on Cole Creek have been overseen by Lake County’s Watershed Protection District (the successor to the Flood Control & WCD) in the decades since.

In conclusion, primary source evidence points to the Cole Creek levee being built circa 1958–1959 by local authorities (Lake County Flood Control District, likely with state and landowner support), in the wake of destructive floods. The U.S. Army Corps of Engineers was not the builder of this particular levee – a misconception likely stemming from confusion with the separate Corps-built levee system in a different part of Lake County. The Cole Creek levee’s origin lies in local flood control efforts to straighten the channel and protect the Green Acres/Soda Bay community, under local jurisdiction and state guidance, rather than any direct federal Corps project.

Sources:

• Lake County Watershed Protection District – Middle Creek Flood Control Project history (Upper Lake levees, built by USACE starting 1958).
• U.S. Army Corps of Engineers, Sacramento District (1974) – Flood Plain Information: Big Valley Streams (Manning, Adobe, Kelsey, and Cole Creeks) – documents channelization and levees on Cole Creek and others as existing flood-control works.
• Clear Lake Hitch (Lavinia exilicauda chi) State Petition (2012) – summarizes mid-century creek modifications: notes a local reclamation levee on Rodman Slough later built up by USACE in 1959, and that other creeks (Scotts, Middle, Clover) were straightened/leveed to protect land (implying Cole Creek’s levee was a similar local effort, since only the Rodman Slough levee is attributed to USACE).
• Lake County Groundwater Management Plan – Big Valley (1999) – describes how Kelsey Creek’s channel was deepened and stabilized in the 1960s to mitigate flooding, reflecting the local flood-control interventions around Kelseyville.
• USACE National Levee Database – Entry for “Lake County Levee 4 (Soda Bay, Cole Creek)” – lists Cole Creek levee (0.46 mi) with Cole Creek as the flood source, but no construction date or federal project info, consistent with a non-federal, locally built levee.
• Historical flood accounts in Big Valley – e.g. Lake County/USGS reports noting flood impacts in 1955, 1958, 1964/65 on Kelseyville streams (context for why the levee was built).