Water Resources Inventory Area 1 Watershed Management

Science Center Objects

In recent years, increased use of ground- and surface-water supplies in watersheds of Washington State has created concern that insufficient in-stream flows remain for fish and other users. In response, the Washington State legislature passed the Watershed Management Act of 1998 (ESHB 2514; see also Ch.90.82 RCW - Watershed Planning), which encourages and provides some funding for local watershed planning and delegates the planning to the local level. As part of this planning, stakeholders within a Water Resources Inventory Area (WRIA) need to assess the status of water resources in the WRIA and, through a water-quantity analysis, determine how much water is available for additional allocation within the WRIA.

The Watershed Management Project for WRIA 1 was established by members of the Initiating Governments; the Lummi Nation, the Nooksack Tribe, the City of Bellingham, Public Utility District No. 1 of Whatcom County, and Whatcom County. The area covered by WRIA 1 includes the Nooksack River and several adjacent watersheds. Federal and State government participation is by the U.S. Forest Service and the Washington State Department of Ecology, respectively. 

WA432 - Water-Quantity Analysis of Water Resources Inventory Area 1, Washington - Part 1, Data Assessment - Completed FY2001

Problem - The water resources of Water Resources Inventory Area (WRIA) 1, which includes the Nooksack River and several adjacent watersheds of Washington State, need to be quantified to determine if sufficient water resources remain for future allocation. The water resources of the WRIA are used for diverse and competing purposes that include timber harvest, mining, industry, recreation, agriculture, and fisheries. Quantifying the water availability of the WRIA includes assessments of both the naturally occurring ground- and surface-water resources and the current and possible future cumulative effects of multiple water uses on the available supply.

Objectives - The evaluation of the water resources of WRIA 1 will be done in two parts and only the first part is included in this proposal. The objectives of Part 1 are to complete the following by December 31, 1999:

  1. compile currently available hydrologic data for WRIA 1;
  2. identify the additional data needed to quantify the water resources of the WRIA using a hydrologic model; and
  3. develop a proposal for Part 2, the development of a hydrologic model for those parts of WRIA 1 where the necessary data are currently available.

It is anticipated that the hydrologic model will consist of a surface-water model for the uplands that may be linked to a ground-water model for the lowlands. It is also anticipated that ground-water/surface-water interactions in the lowlands will be simulated using a monthly timestep.

Relevance and Benefits - The proposed work (Part 1) forms the basis of work to be conducted during Part 2, which will be relevant to the USGS mission. During Part 2, the study will address several priority water-resource issues identified in the strategic plan of the Water Resources Division for 1998-2008 (described in http://wwwqvarsa.er.usgs.gov/~gcomfort/Strategic_direction/). Specifically, the issues that are addressed in whole or in part are

  1. Effects of urbanization and suburbanization on water resources
  2. Effects of land use and population increases on water resources in the coastal zone
  3. Drinking water availability and quantity
  4. Suitability of aquatic habitat for biota
  5. Effects of climate on water-resource management
  6. Surface-water and ground-water interactions as related to water-resource management
  7. Hydrologic-system management, including optimization of ground-water and surface-water use.

A comprehensive study of the water availability in WRIA 1 includes assessing the effects of land use and land cover, water use, and climate on the quantity of ground- and surface-water resources (issues 1, 2, 3, 4, 7, and 8). Although ground- and surface-water quality are not addressed in the study, information about water quantity will form the basis for possible future water-quality assessments and optimum-use scenarios. For example, as future ground-water withdrawals increase in WRIA 1, upconing of conate seawater and seawater encroachment may occur in parts of the lowlands and the coastal areas, respectively, and in-stream flows help determine TMDLs.

Results of the study will allow the cooperators to manage the water resources of WRIA 1 as one integrated system. In future phases, the USGS may assist the cooperators in identifying optimum ground-water and surface-water use scenarios (issue 9).

In its Science Plan, the USGS Washington Water Science Center identified water availability as one of the five most important water-resource-related issues in the State of Washington. Part 2 of the study addresses the water-availability issue by quantifying the relations in space and time between water availability and water use, using currently available data and by determining what additional data are needed to improve the quantification of those relations in the future.

Specific benefits to the USGS that will be provided by the proposed work are opportunities to

  1. Help define the best methods and approaches to quantify water availability in WRIAs to be studied in the future by private industry and other entities. The Washington State Department of Ecology is considering making water-quantity studies of four WRIAs examples for future studies of other WRIAs by investing more heavily in these studies. It is expected that WRIA 1 will be selected as one of the example areas;
  2. Identify the parameters that are most important to define the ground-water/surface-water interaction. This information may be used to help direct future data collection in WRIA 1 and other basins with similar characteristics;
  3. Quantify the interactions between the ground-and surface-water systems of the WRIA 1 lowlands with a ground-water flow model using currently available data. These interactions are poorly understood, but their understanding is of vital importance if available water resources are to be quantified; and
  4. Link surface- and ground-water models.

Approach - Available data will be compiled or, if applicable, estimated, to complete the following tasks that are outlined in the workplan of the Watershed Management Project: delineations of watersheds; descriptions of the ground- and surface-water systems; descriptions of soils; descriptions of historical, current, and potential future land use and land cover; and estimations of reference evapotranspiration, average monthly precipitation, and water use.

Links to compiled data and data descriptions will be provided on a public-access world-wide web page. Limited interpretive information will be published on-line and in paper format as U.S. Geological Survey Open-File Reports.