Wetlands Page Banner
KWERI Mission Values Goals Vision Organization Wetlands Projects Strategy Publications Progress

Agency Lake Treatment Wetlands

Executive Summary

We are developing a conceptual design for a treatment wetland restoration project for Agency Lake and Barnes Ranches (collectively referred to as Agency Lake Wetland [ALW]) with the intent of capturing agricultural return flow from Wood River Valley ranches and sequestering a large fraction of the nutrients it contains for the purpose of rebuilding peat and reversing subsidence. We expect, this will effect the reduction of phosphate in the water and have a substantial effect on the water quality of Agency Lake and possibly Upper Klamath Lake. The conceptual design will hopefully allow us to project the range of possible outcomes and potential impacts this will have on the birds, fish and other wildlife and plants in this system. We hope to also develop an aspect of this project that will investigate the use of high-efficiency nutrient sequestration zones within the wetland that will make use of biological or chemical chelation/precipitation methods to further enable nutrient capture. This may have particular application in recirculating waters already in the lake system through such zones in a manner that will further reduce lake nutrient loads.

Introduction

As discussed on several other pages on this site, Upper Klamath and Agency Lakes have become hypereutrophic primarily because agricultural diffuse source phosphorus pollution has added to the naturally phosphorus-rich surface and groundwaters to overload the system. {Bortleson:1993ta, Bradbury:2004vn} A major contribution to the problem has been the diking and draining of the majority of historical wetlands for agricultural production, particularly lake fringe wetlands, which might have otherwise cleared these waters of a significant portion of the phosphorus (P) {Bradbury:2004vn}. This has led to massive algal blooms that over the past century to a near monoculture of Aphanozomenon flos-aque (AFA), a species that was either nonexistent in this system, or was present only as a very minor player. {Bradbury:2004vn}.

Cyanobacteria
Left panel is microscopic view of Microcystis colonies
Righe panel is a ball of AFA filaments with several loose surrounding in a soup of Microcystis
AFA is a filamentous cyanobacterium (Blue-Green Alga) that is special in the sense that it is a vigorous fixer of atmospheric nitrogen. That is it takes nitrogen gas (N2) which comprises about 80% of the atmosphere, and through a very energetic process, converts it to ammoninium (NH4)+ in a process called Nitrogen Fixation. It forms large filaments quite visible to the naked eye.

This project begins by developing a conceptual design for a treatment wetland restoration project for Agency Lake and Barnes Ranches (collectively referred to as Agency Lake Wetland [ALW]) with the intent of capturing agricultural return flow from Wood River Valley ranches and sequestering a large fraction of the nutrients it contains toward rebuilding peat and reversing subsidence. We expect, this will effect the reduction of phosphate in the water and have a substantial effect on the water quality of Agency Lake and possibly Upper Klamath Lake. The conceptual design will hopefully allow us to project the range of possible outcomes and potential impacts this will have on the birds, fish and other wildlife and plants in this system. We hope to also develop an aspect of this project that will investigate the use of high-efficiency nutrient sequestration zones within the wetland that will make use of biological or chemical chelation/precipitation methods to further enable nutrient capture. This may have particular application in recirculating waters already in the lake system through such zones in a manner that will further reduce lake nutrient loads.

WRW N Levee looking SW
Looking SW from Wood River Wetland north levee
twoard Pellican Butte and the Mountain Lakes

Our primary measurable goal is to improve water quality to the point of substantially reducing the Aphanizomenon flos-aquae population in the lake as measured by comprehensive remote sensing technologies. Our goal is to prevent ‘blooms’ in the lake in a vast majority of years.

Our primary indirect goals are to:

Agency Lake should become the primary target for water quality improvement in the near future for three reasons:

Hydrological models and a detailed P budget of Agency Lake should be developed. This has been done (Walker, 1995; CH2M Hill, 2012; Walker, et al., 2012), but these should be updated with the capacity to include elements of water treatment for improving water quality.

KWERI maintains that the elements of this proposal can guide a long-term solution (i.e. 5-100 years until the situation is fully remediated) to the UKL Watershed water quality problem. We also assert that the suggested process presents a short term rescue scenario for endangered sucker species by cleaning the system in stages providing refugia. By applying carefully designed processes one by one and gaining further research findings, KWERI believes that there is a strong probability that the work on AL can be a model for expanding treatment for the entire UKL system such that the entire system can be returned to a much lower level of eutrophication.

Agency Lake: A Keystone Water Body

Agency Lake is often thought of as simply an extension of UKL. In fact, some authors early in their papers just note that they consider them one and the same and then no longer mention AL. However, we take quite a different view. Agency Lake is a much smaller volume of water, and hence it will be cleaned much more quickly than the whole of UKL. The FWS has recently included the Wood River and Crooked Creek, both tributaries of AL as critical habitat for the endangered suckers. Redband trout are also resident in this lake as are a plethora of the minnows they feed upon. With the vast improvement in sucker larval habitat being provided by the WRD restoration and its reconnection to Agency Lake by direct levee breaches at the south end of AL, can juvenile sucker find refuge in Agency Lake and benefit substantially in the short run? Could this be the answer to improving adult sucker recruitment during this critical period when the late summer die-off of young-of-the-year suckers seems to be negating at least some of the benefit of the WRD larval sucker habitat improvements? Concomitant with efforts to restore water quality in Agency Lake, we would like to do much more research on this lake as sucker habitat, especially during this critical period of their maturation.

Another aspect of how key AL is to the lake system and especially to the endangered suckers, is its position in the flow of waters through the watershed. Waters from the watershed surrounding the Wood River Valley (WRV) flow through AL and Agency Strait and into the northern reaches of UKL. Due to the substantial flow of cleaner, cooler water already entering this zone of UKL from Crystal Creek, Mossy Creek, the southern Fourmile Creek and Thompson Creek, this zone of the lake is already cleaner and cooler than the southern reaches. These waters have already been cleansed by passage through the historical wetlands of the UKLNWR. Suckers and other fishes are known to take refuge in this area during the late summer. Effective cleaning of AL waters would add to these waters and increase greatly the size of this refuge zone, and this attachment with cleaner water inflows may lead to increasing use of AL as refuge water for all these fishes

Table of Contents

  1. Introduction to Expanded Vision Discussion
  2. Upper Klamath Lake Watershed
  3. Historical Function of the Lake System
  4. Lake System Restoration Opportunities - these sections still in draft
    1. Treatment Wetlands
    2. Links below have not yet been populated... Sorry for the delay!
    3. Recirculating Wetlands
    4. Subsidence Reversal
    5. Reconnection of Large Band Lake Fringe Wetlands to the Lake System
    6. Public Outreach and Education
    7. UKL Water Quality Economic Analysis
    8. Ramsar Convention Recognition
  5. Walker Rim Groundwater Dependent Ecosystem