By Michael Wilmar and Misti Schmidt

On May 31, the Court of Appeal for the First Appellate District endorsed the State Water Resources Control Board’s four-part test of whether groundwater is a “subterranean stream flowing through known and definite channels.” The Board first used this new test in its 1999 decision, In re Garrapata Water Co., which expanded the Board’s authority over groundwater.

Historically, the Board’s authority has been restricted to a few known riparian subterranean flows and has excluded ambiguous or unknown bodies of water from permitting requirements. The expansion of this authority via a liberal reading of the Garrapata test received a nod from the court, which painstakingly walked through each element of test to determine if:

  1. A subsurface channel is present
  2. The channel has a relatively impermeable bed and banks
  3. The course of the channel is known or capable of being determined by reasonable inference ; and
  4. Groundwater is flowing in the channel.

This case came before the court when the North Gualala Water Company (“NGWC”) protested its obligation to file for a permit from the State Water Resources Control Board (“Board”) for its two groundwater pumps. According to Water Code Section 1200, the only groundwater the Board has jurisdiction over is that found in subterranean streams flowing through a known and definite channel. Using the Garrapata test, NGWC claimed that its groundwater did not fall into this category because it failed to satisfy three of the elements: 1) the channel does not contract or narrow in the direction of the flow, 2) the bedrock is permeable, and 3) the groundwater is not flowing in the channel.

Because the test comes from the 1899 California Supreme Court Case, City of Los Angeles v. Pomeroy, (1899) 124 Cal. 597, from which the Water Code language was derived in 1914, the court laboriously analyzes the facts of the case and each contested step of the test in light of Pomeroy. The court determined that the Board’s broad interpretation of each test element was proper. First, the channel does not need to contract or narrow in the direction of the flow. Although the high court in Pomeroy states that a “defined” channel means a “contracted and bounded channel,” the First Appellate District Court states too much weight must not be placed on the word “contracted.” Contracted merely means that the channel constrains and controls the groundwater, as opposed to how the groundwater would flow without the channel.

Similarly, on the second question of impermeability, too much emphasis must not be placed on the channel’s boundary. According to Pomeroy, the bed and banks must present a “significant boundary to groundwater flow.” The Board’s position focused only on whether the groundwater can leave the channel through permeable banks and compares the permeability of banks with that within the channel, a position with which the court agrees. The source of the water or the direction from which the water originates is unimportant. If a smaller portion of water leaves the channel as compared to the amount of water that entered it and if the bank of the channel is two and one-half to three orders of magnitude less permeable than the soil within the channel, then the bank is relatively impermeable and thus passes the Garrapata test.

The final contested element, that of flow direction, also must not be too strictly construed. At any one place, the water flow need not be flowing in the general direction of the channel because there can be different sedimentation or topographical changes in that small area while the entire stream is unaffected overall.

The Board’s decision on these points were upheld on the basis that substantial evidence was present in the administrative record to support the Board’s findings. The court explicitly endorses the Board’s use of the Garrapata test over an alternative test proposed by NGWC.

For more information please contact Michael Wilmar and Misti Schmidt.  Michael B. Wilmar is special counsel in the Real Estate, Land Use and Natural Resources Practice Group in the firm’s San Francisco office.  Misti Schmidt is an associate in the Real Estate, Land Use and Environmental Practice Group in the firm’s San Francisco Office.