Rice Lake Management Plan

Water Quality

History

Water Clarity

Target Secchi Disc Summer Average – 4.6 feet

Range of Summer Averages – 2.2 feet (1995) to 5.2 feet (2000)

Target met or exceeded in 2000 (5.2 feet) and 2001 (4.5 feet).

Total Phosphorus

Target TP Summer Average – 36 ppb

Range of Summer Averages since 1995 – 152 ppb (2002) to 469 ppb (1998)

Target was not met in the 1995 to 2003 sampling period.

Chlorophyll-a (Algae)

Target Chloro-a Summer Average – 12 ppb

Range of Summer Averages since 1995 – 18 ppb (2002) to 44 ppb (1995)

Target was not met in the1995 to 2003 sampling period.

Current Trend

Water Clarity

Nine year summer average (1995 – 2003) – 3.5 feet

Five year summer average prior to 2000 – 2.8 feet

Four year summer average since 2000 – 4.3 feet

This is 23 % better than the long term average.

Total Phosphorus

Nine year summer average (1995 – 2003) – 286 ppb

Five year summer average prior to 2000 – 344 ppb

Four year summer average since 2000 – 213 ppb

This is 26% better than the long term average.

Chlorophyll-a

Nine year summer average (1995 – 2003) – 30.3 ppb

Five year summer average prior to 2000 – 35 ppb

Four year summer average since 2000 – 24.5 ppb

This is 19% better than the long term average.

In spite of the improvement over the last four years the total phosphorus levels are still in the hypereutrophic range and the water clarity and the chlorophyll-a levels are in the eutrophic range.

1

Phosphorus

This element is the primary focus in water quality management.  By reducing phosphorus loading externally and internally to the lake, algae blooms will begin to decrease and water clarity will begin to increase.  However, this is a slow process.  Just as the lake didn’t deteriorate overnight so to it isn’t going to improve overnight either.  Through persistence in good water quality practices, improvements should be steadily realized.

External Phosphorus Load – These are sources of phosphorus that come from outside the  lake in the watershed.

Watershed – The watershed for Rice Lake is 17,200 acres excluding the lake area of 333 acres.  This is about a 52 to 1 ratio when comparing the size of the watershed to the lake size.  Due to the stormwater drainage system everyone in the watershed is essentially a lakeshore owner since what comes off of their lawns runs directly into the lake.

Development – This is continuing to expand and change the watershed.  Phosphorus loads normally increase as more of the watershed becomes impervious.

Shoreline – This area is essentially fully developed so now the goal is to reduce the adverse impacts.  Much of the immediate shoreline is covered with natural vegetation, but there are some areas where buffer strips could be reestablished.

Solutions

Watershed Analysis – The watershed should be modeled to determine phosphorus loading and locate hotspots where stormwater ponds or rainwater gardens would be most effective.  It would also identify those stormwater ponds near the lake and Elm Creek where alum treatments could be done to improve their phosphorus removal efficiency.  It is recommended that this be done this winter so that the construction and treatments can begin next spring.  The portion of the watershed around Rice Lake could be done first and then as funding assistance became available for the Elm Creek portion, work could start later on it.

Cost for area around Rice Lake:  60 hours @ $75.00/hr. = $4500.00

Cost for area along Elm Creek:  60 hours @ $75.00.hr. = $4500.00

2

Rainwater Gardens – Shallow depressional areas planted with water tolerant plants that catch and absorb up to 60% of annual runoff. These can be placed anywhere in the watershed, especially in areas where there are no stormwater ponds.

Cost:    $5.00/sq. ft. to do it yourself.

$12.00/sq. ft. for a professional.

Check Dams – These can be placed in grassy swales to slow down and help runoff to absorb into the soil before entering the lake.  They can also be planted similar to rainwater gardens.

Cost:  Same as for rainwater gardens

Buffer Strips – Strips of natural vegetation planted along the shoreline from 15’ to 25’ wide that filter and absorb yard runoff before entering the lake.

Cost:  About $100.00/lineal foot of shoreline.

Lake Scaping – A combination of the above along with trees, shrubs, and emergent aquatic vegetation planted in yards along the shoreline.

Cost:  Same as for buffer strips.

BMP’s – Best management practices other than those above such as pet waste pickup, keeping grass clippings and leaves off the streets, etc . (See brochure)

No Phosphorus Fertilizer – Encourage compliance with new state law restricting use of phosphorus fertilizers.

Stormwater Ponds – These are required on all new developments and are quite effective, however they are absent from most of the lakes’ watershed.

Aluminum Sulfate (Alum) Treatment of Stormwater Ponds - This is a non-regulated chemical that absorbs phosphorus and inhibits its release for utilization by algae.  It comes in liquid or dry powder form and can be used to make stormwater ponds more efficient in removing phosphorus before it enters the lake.  Dry alum can be placed at inlet pipes to treat incoming stormwater.  Also the stormwater ponds can be treated by a professional from a boat using either dry or liquid formulations.

3

Cost to treat inlet pipes:

Dry alum is about $86.00 for 100 lbs.

-First hour @ $125.00 (includes travel time) and each additional hour - $75.00

-Total treatment cost would be about $215.00 per treatment.

It is proposed to treat stormwater ponds in the watershed of Rice Lake with alum to remove phosphorus and increase their efficiency.  It is recommended that this be done by a professional lake treatment company.

It is estimated that three treatments per summer would be needed and the estimated cost for each treatment would be about $1000.00/acre.

It is also recommended that before and after treatment monitoring be conducted to evaluate success and longevity of treatments.

-First hour @ $125.00 (includes travel time) and each additional hour - $75.00

-Cost of samples - $50.00 each

-Total monitoring cost = $350.00 per treatment

DNR Grant - An application will be prepared and submitted in 2005 to the DNR for a grant to plant buffer strips on several adjoining lots.  A survey will be done to locate a suitable area.

The Aquatic Plant Restoration Program of the DNR provides funding for shoreline buffer strips.  The process would involve submitting an application and having the DNR staff visit the sites.

The time needed for this process would be two one-hour site visits and seven hours to prepare the application.

The cost for the site visits would be $125.00 each totaling $250.00 and $75.00 per hour for the grant application totaling $525.00.

The total cost to complete the grant application would be $775.00.

Goose Control – Their droppings are high in phosphorus and anywhere native tall grass prairie can be restored in turf grass areas along with buffer strips will discourage geese because it limits their visibility.

Cost to establish native prairie strips along sidewalks - $25.00/lineal foot

4

Local Control and Funding – It is recommended that the association conduct fundraisers to provide funding of these projects along with government agencies funds.

Internal Phosphorus Load – These are the sources of phosphorus that come from within the lake.

Sources

Curlyleaf pondweed – This is an exotic aquatic plant from Eurasia that crowds out native aquatics and dies in midsummer releasing its nutrients.  These nutrients are then utilized by algae to cause a bloom.

Carp – Where they are found in significant numbers, their spawning and feeding behavior cause increased turbidity and make phosphorus more available for algae.

Bottom Sediments – These also contain high levels of phosphorus which can become resuspended in the water column as a result of heavy wind storms.  Phosphorus can also be released from the sediments when dissolved oxygen levels drop below 1 ppm.

Solutions

Curlyleaf pondweed control

Drawdown – This was done in the winters of 96,97; 97,98; and 02,03 to a depth of 5.5 feet and is the least expensive and most effective method to control curlyleaf pondweed and should be utilized as often as necessary.

Harvesting – This should be done in early to mid-June when the plants are at peak biomass and before the winter buds (turions) drop off.  It is effective to about six feet of depth.  However, this may not be possible without a suitable boat launch.

Herbicide treatment – Early spring application of Aquathol K has been shown to be effective at controlling curlyleaf pondweed without damaging native aquatic plants.  However, only 15% of the lakes’ littoral area can be treated with an herbicide.

To exceed the 15% limit (50 acres) will require a variance and an Aquatic Plant Management Plan will need to be developed to get the variance from the DNR.

5

Aquatic Plant Management Plan - Both of the exotic species of submerged aquatics, Eurasian Water Milfoil and Curlyleaf Pondweed, are found in Rice Lake.  In order to develop the APMP several aquatic plant surveys would need to be done.  The time needed to conduct a plant survey is about 3 hours and would cost $125.00 for the first hour and $75.00 for each additional hour or $275.00 per plant survey.   It is estimated that three surveys would need to be done each year for an annual total of $825.00.  This monitoring would be required for five years.

The time required to write the Aquatic Plant Management Plan would be about 10 hours at $75.00 per hour for a total of $750.00.  It is recommended that this be done this fall or winter to allow time for DNR approval so that treatments can begin next spring.

The cost for treatment of the area of the lake not affected by the drawdown would be about $475.00/acre.

The cost for treatment of individual patches of curlyleaf pondweed that may reappear in the affected area would be about $375.00/acre.

Carp Management

Carp are detrimental to good water quality and the DNR Fisheries Supervisor has agreed to give a permit to remove them to another commercial fisherman if necessary.

An optimal time for the removal would be after the drawdown this fall but before the lake freezes.

War on Carp – It is recommended that catching and keeping carp of all sizes be encouraged and promoted.  To start with a commercial fisherman should be encouraged to take as much as he can.  Seines could also be utilized by volunteers to take advantage of opportunities.  Another possibility would be to hold a fishing tournament where prizes would be given to the largest number of carp caught.  Funds for the prizes could be raised from a concession stand.  The state of Virginia encourages removal of carp and stocking of gamefish such as largemouth bass, crappies and northern pike that are heavy fish feeders because carp graze on larger sized zooplankton which feed primarily on algae.

6

After the commercial fisherman has taken all that he can or wants it is recommended that the association apply for a permit from the DNR to remove as many of the carp that remain as possible using two bag seines.  One 200’ by 6’ and the other 50’ by 4’.

Cost of two seines = $1100.00

If the DNR will not grant a permit, dipnets up to a 2 foot diameter, spears, harpoons, and bow and arrow can still be used after May 1st to take carp in unlimited number and may be bought or sold.

Time for coordination - $75.00/hour

Time for field visits or surveys

-First hour @ $125.00 (includes travel time) and each additional hour - $75.00

Alum Treatment

In-lake alum treatments are very effective in lowering phosphorus levels in the water column and binding up the phosphorus in the sediments, which results in greatly improved water transparency.  However currently only one treatment is allowed by the MnDNR and it is recommended that this be done only after the watershed is totally developed and stabilized.

The estimated cost would be about $530 per acre.

Iron Treatment

This is being done experimentally on Eagle Lake and if it proves successful in lowering inloading of phosphorus by binding up the phosphorus in the bottom sediments and possibly impacting curlyleaf pondweed, it could be considered it in the future.  This would also require a permit from the DNR.

Copper Sulfate Treatment

In-lake copper sulfate treatments do not directly lower phosphorus levels like alum, but it may have an indirect effect by killing the algae, thereby keeping the water clearer to promote continued growth of macrophytes.  One-half of the lake would be treated at a time about a week apart in July at estimated cost of $8400.00.

7

Fishing

Fisheries Surveys – The MnDNR Fisheries last surveyed the lake in 1994 in mid July and because there is no boat launch there are no resurveys currently scheduled.  There was a winterkill over the 1995-1996 winter and there have been no surveys since then.  However, bass, sunfish, crappies, and northern pike were stocked by the association in 1998 and 1999.  This increases the importance of such methods as spawning bed checks, creel surveys, and carp removal to assess the fish population status.

Spawning Bed Checks – These will be conducted for largemouth bass, crappies, and sunfish to determine numbers and size of spawning fish and the amount of spawning habitat available.  A determination of spawning interference by carp will be made.

Populations of panfish such as bass, crappies and sunfish can be assessed by observing spawning beds, since they usually construct nests in shallow water.

Crappies are the first ones to use these spawning beds once the lake temperature reaches about 60 degrees.  This usually occurs in late April to early May.

Largemouth bass follow the crappies once the lake temperature reaches about 65 degrees, usually in mid to late May.

Sunfish species follow the bass when the lake temperature reaches about 70 degrees, usually in late May through mid-June.

By observing these spawning beds at the right time the size and abundance of the adults can be determined.

Three separate checks are needed and the time needed for each check would be three hours.

-First hour @ $125.00 (includes travel time) and each additional hour - $75.00

-Total = $275.00 per check

-Grand Total = $825.00

8

Creel Surveys – This is recommended to monitor the amount, species and size of the fish being caught by anglers.

Cost:  First hour @ $125.00 (includes travel time) and each additional hour - $75.00

Estimated Total = $200.00 per survey

Stocking – This will be recommended based on the findings of the spawning surveys.  The fish for stocking will need to be purchased from a private fish hatchery and a permit from the DNR will be required.

Catch and Release – It is recommended that this be encouraged for all of the larger gamefish since it will help protect the spawning size adults.  This could be promoted through the newsletter.

Winter Aeration – It is recommended that the current program be continued as necessary as determined by dissolved oxygen checks.

Cost for dissolved oxygen checks is $125.00.

Fishing Pier – This is recommended to be placed at a suitable location to enhance the fishing opportunities for local youth.

Cost for pier is about $20,000.00.

Shore Fishing Areas – These are areas comprised of large limestone blocks at suitable locations to designate areas along shore for fishing and protect against erosion.

Cost per shore fishing area is about $2000.00

Slot Limits – This is a technique also used to protect mature gamefish from over fishing.  It would need to be coordinated and approved by the MnDNR Fisheries Section.

9

Project Cost Summary

Consulting Fees - $75.00/hour

Transportation Cost - $25.00/hour

Watershed Analysis - $9000.00

Rice Lake - $4500.00

Elm Creek - $4500.00

Alum Cost - $0.86/lb. or $43.00 per 50 lb. bag

Rain Garden Construction Cost (do it yourself) - $5.00/sq. ft.

Rain Garden Construction Cost (professional) - $12.00/sq. ft.

Check Dam Construction – Same as rain gardens.

Buffer Strips - $100.00 per lineal foot.

Lakescaping - $100.00 per lineal foot.

Native Prairie Strips - $25.00/lineal foot

Alum Treatment of Stormwater Pond Inlets - $86.00 for 100 lbs. of alum and same as above for labor.

Estimated Time – 1 hour ($125.00 plus $86.00 for alum)

Alum Treatment of Stormwater Ponds - $1,000.00 per acre

Alum Treatment of Rice Lake - $530 per acre

Stormwater Pond Monitoring - $350.00 per treatment

Copper Sulfate Treatment - $25 per acre

DNR Grant Application - $775.00

Aquatic Plant Management Plan - $750.00

Aquatic Plant Surveys – Same as above for labor.

Estimated Time – 3 hours ($275.00)

10

Herbicide Treatment of Area Not Affected by Drawdown - $475.00/acre

Herbicide Treatment of Area Affected by Drawdown - $375.00/acre

Carp Management – Same for labor

Estimated Time – 2 hours per visit ($200.00)

Spawning Bed Checks - $125.00 for the first hour and $75.00 for each additional hour

Estimated Time – 3 hours ($275.00)

Creel Surveys - $125.00 for the first hour and $75.00 for each additional hour

Estimated Time – 2 hours ($200.00)

Dissolved Oxygen Checks - $125.00

Fishing Pier - $20,000.00

Shore Fishing Areas - $2000.00

Board Meetings - $125.00

Terms for Projects:  50% downpayment and 50% upon completion.

11