An Update on the Status of Iowa's Shallow Lake Renovations

Vince Evelsizer – Iowa Dept. of Natural Resources

Talk Outline • Intro/background of our shallow lakes

• Update on progress

• Successes

• Challenges

• Individual shallow lake profiles

• What’s been learned - future management

Introduction/Background

What Changed – Shallow Lakes Died

• Major changes in hydrology

• High and stable water levels

• Wetland loss in their watersheds

• Increased nutrients and sediment

• Little to no aquatic vegetation

• Open, wind swept

• Abundance of rough fish

(carp, bullhead and fathead minnows)

Some have been this way for 50 – 80 years!

Scientific Literature to Support Changes….

Fortunately many studies have documented several aspects of shallow lake ecology and the management implications

Studies produced from: • Canada • Minnesota • Netherlands/Europe • Other Midwest States

Diamond Lake Dedication, July 2009

Partners

• NAWCA

• Lakes Restoration Program

• Lake Associations

• Hundreds of local citizens and businesses

• Ducks Unlimited

• Pheasants Forever

• Iowa Natural Heritage Foundation

• The Nature Conservancy

• U.S. Fish and Wildlife Service

• U.S. Dept. of Ag (WRP, CRP, etc.).

• DNR programs and staff

• others

The vision for Living Lakes is to establish stepping-

stones of perpetually protected and managed shallow

lake/marsh complexes from southern Iowa through

northern Minnesota to provide quality wetland food

and habitat resources for waterfowl. The initiative will

help preserve this region’s rich waterfowling heritage

and support conservation of the primary source of its

birds, the prairie breeding grounds.

The Living Lakes Vision

Courtesy of DU

Diamond Lake, 2009

Shallow Water Management requires a

watershed and in-lake approach

In – Lake “Renovations” Getting water level control !

Drawdown and Carp Removal

In-Lake; Replacing old water control structures

Pickerel Lake July 2014 – New Control Structure

Updates on Progress

The top priority for renovating shallow lakes is getting back their

Ecological Health

Successes

• 37 projects; >14,000 acres affected

• Shallow lakes/wetlands – positive abiotic/biotic response in all cases so far

• Lots of partnering and communication

• Monitoring

• Funding has been available

• In many cases several types of recreational use has spiked upward

• Some examples…..

West Hottes/Marble

Renovated in 2014 – series of water control structures

Wildlife Use – West Hottes/Marble

West Hottes Opening day of duck season

Trumbull Lake

Renovations started in 2012; more done through 2014 ‘Mini-drawdowns’ (~14 inches) occurring 2014 – 2016 Challenge: Carp re-entry

Ventura Marsh

Renovation: 2009 – 2012

Aquatic Veg, clearer water, muskrats!

Challenge – Carp re-entry

Dan Green Slough Pre - renovation

Dan Green Slough - Post - Renovation

A large marsh renovated 2009 – 2012

Rice Lake

Renovation started in 2012

Challenges – phosphorous/algae blooms

New WCS – Rice Lake

IA DNR Shallow Lakes Monthly

Monitoring Schedule

Sample Months Number of Lakes

to Monitor Regular Sampling (WQ and Nutrients)

Plankton Plants Inverts Fish

May

16

X X

June

16

X X

July

16

X X X X

August

16

X X X

Sept

16

X X

Challenges

• Trees

• Fish

• The wrong kind of aquatic vegetation response

• Weather

• Nutrient/pollutant/broken watersheds

• Different opinions – recreational use

• Some examples….

Diamond Lake – Renovation completed by 2009

Diamond Lake – Aquatic Vegetation

Diamond Lake – Post Renovation

Illustrates Annual Changes - Dynamic

Virgin Lake – October 2014

Challenge – ‘Looks’, dead trees; however very good wildlife response

Ethan’s 1st Duck – Virgin Lake

Lizard Lake – Post Renovation

Challenge - Hybrid Cattail Domination

Things can get complicated ! Shallow Lake & Marsh Management is a Science and an Art

A perfect example of “adaptive resource management”

Hmmm…Should I put some more stop logs in? How many? How much will it rain?

This can be complicated for a multi-use shallow lake. People care about the outcome; the managers hope it works out!

It’s an iterative, dynamic process!

• Shallow Lake Mgmt – Rapid Evolution

– Fairly finite resource in Iowa

– Active mgmt on places that hadn’t had it for yrs

– A big deal locally

– New and old partners are needed

– Community support needed for success

– Manage for WQ and ecol health

Future

• Wide variety of partners; community support; waterfowl managers need to embrace this!

• Shallow lake management plans – clear up details

• Monitoring parameters will document and trigger mgmt decisions – science

• Each shallow lake is unique

• Some compromises are needed, any positive changes to a system is better than nothing…

Take – Home Messages Shallow lake renovations: Are they working? - YES! ……so far anyway - Not easy, require a lot of steps, money, patience, - Shallow lakes are dynamic - Communication is key - Community support is key - Partners and cooperation is key - Monitoring and follow-up are necessary - Whole system/Ecological/Water Quality Driven

Questions?

Fish Complicate the Management Process - What assemblage of game fish? - Fish take awhile to grow - Shallow Lakes are dynamic; not stable - Effects the timing of renovations