engineer’s report drainage district no. 33

Engineer’s Report

Drainage District No. 33 Main Open Ditch & Proposed Lateral 9 Facility Improvements Cerro Gordo County, Iowa

Filed February 19, 2019 Submitted by:Bolton & Menk, Inc. 1609 U.S. Hwy 18 East Algona, IA 50511 P: 515-395-3140

Proj. No. P13.115455

Prepared by: Bolton & Menk, Inc. Table of Contents Drainage District No. 33, Main Open Ditch and Proposed Lateral 9 ǀ P13.115455 i

Table of Contents I. INTRODUCTION ................................................................................................................... 2

SCOPE OF WORK ................................................................................................... 2

LOCATION & DISTRICT FACILITIES ......................................................................... 2

HISTORY SUMMARY .............................................................................................. 2

II. INVESTIGATION ................................................................................................................... 3

SURVEY & INVESTIGATION ................................................................................... 3

CAPACITY ANALYSIS .............................................................................................. 3

III. PROPOSED REPAIR .............................................................................................................. 4

OPEN DITCH IMPROVEMENT ................................................................................ 4

PROPOSED LATERAL 9 TILE IMPROVEMENT......................................................... 4

WORK LIMITS & DAMAGES ................................................................................... 4

ROAD CROSSINGS .................................................................................................. 5

IV. OPINIONS OF PROBABLE COST ........................................................................................... 5

V. DISTRICT RIGHT-OF-WAY .................................................................................................... 5

VI. FARM PROGRAM COMPLIANCE .......................................................................................... 6

Farm Program Wetland Conservation Rules ........................................................ 6

Converted Wetland Mitigation Alternatives ........................................................ 7

Wetland Mitigation Policy .................................................................................... 8

VII. CLEAN WATER ACT COMPLIANCE ....................................................................................... 8

VIII. WATER QUALITY ................................................................................................................. 9

IX. ANNEXATION .................................................................................................................... 10

X. RECLASSIFICATION ............................................................................................................ 10

XI. SUMMARY & DISCUSSION ................................................................................................ 11

Appendices Appendix A: Petitions

Appendix B: Tile Capacities

Appendix C: Opinions of Probable Cost

Appendix D: Right-of-Way Tabulation

Appendix E: Preliminary Plans

Prepared by: Bolton & Menk, Inc. Drainage District No. 33, Main Open Ditch and Proposed Lateral 9 ǀ P13.115455 2

I. INTRODUCTION

SCOPE OF WORK

The purpose of this report is to provide information relative to drainage relief requested by landowners of Drainage Districts No. 33, Cerro Gordo County, Iowa (DD33). The Board of Supervisors appointed Kent L. Rode, P.E., Bolton & Menk, Inc. to complete the necessary preliminary survey, study, and engineering report.

This report addresses landowner requests for annexation and establishment of an additional facility associated with DD33. This report examines the conditions that would be necessary to extend drainage relief to landowners that are underserved by the current drainage infrastructure. In addition, this report discusses the annexation of materially benefited lands laying outside of the current assessment boundary along with reclassification of all benefited lands. A copy of the drainage petition is attached with this report in Appendix A.

LOCATION & DISTRICT FACILITIES

The watershed of DD33 lies within Cerro Gordo County located generally west of the City of Rockwell. The current watershed of DD33 is in Sections 4, 5, and 8 of Geneseo Township (T-94-N, R-20-W) and Sections 32 and 33 of Bath Township (T-95-N, R-20-W). Based on existing maps there are approximately 730 acres currently assessed for benefits on the existing district schedule. The petition requests annexation of lands in parts of Sections 5 and 6 of Geneseo Township (T-94-N, R-20-W) and parts of Sections 29, 31, 32, and 33 of Bath Township (T-95-N, R-20-W).

Drainage Districts No. 33 consist of an open ditch and main tile system with eight lateral tile systems. The Main Open Ditch of DD33 outlets to the East Branch of Beaverdam Creek. The East Branch of Beaverdam Creek becomes Beaverdam Creek which outlets to the West Fork of the Cedar River and eventually the Cedar River. The Cedar River continues south and drains to the Iowa River and then the Mississippi River.

HISTORY SUMMARY

Bolton & Menk conducted an investigation based on records found at the Cerro Gord County Courthouse. This information was gathered in order to better understand the drainage district’s history. A summary of events based on these records is as follows:

July 29, 1915 Application to Board of Supervisors for County Drain

August 2, 1915 Commission to Engineer for survey and examine lands for Drainage District.

May 17, 1916 Hearing for establishment of district. District Established. No claims for damages filed and no objections filed.

August 16, 1916 Notice to bidders published. Completion date of January 1st, 1917 agreed on. Commission to assess benefits for classification

September 5,1916 Bids accepted and awarded. Contractor, Martin Jenson, awarded job for Drainage District 33.

September 12, 1916 Contract and specifications for Drainage District 33 filed


December 22, 1916 Contractor request for extension of completion date to June 1, 1917.

September 1st, 1917 Certified that contractor has completed Drainage District 33 and has been paid in full

October 15, 1917 Resolution fixing date of hearing on report of commissioners to benefits in drainage district 33. Levied an assessment that estimated cost of reclamation and improvement of district 33 to be greater than should be levied.

January 8, 1918 Bid bond resolution for Schanke & Company for Improvements

November 27, 1922 Reassessment to pay deficit in construction for repairs

July 2, 1962 Board rules that no farm animals are to be in the drainage ditch.

II. INVESTIGATION

SURVEY & INVESTIGATION

During the fall and winter of 2018/2019, a field review and preliminary survey was performed for the Main Open Ditch and an existing private drainage tile that outlets to the Main Open Ditch. Topographic data was gathered along the open ditch to determine the outlet status of the existing private tile. Additional data was gathered above the approximate location of the existing private tile to determine existing cover amounts and facility condition.

Based on information obtained in the survey, the general size, slope, and condition of the existing private drainage tile were determined. The existing 12-inch private tile drains land west of DD33. The tile is plugged and failing underneath the Union Pacific Railroad near the center of Section 5 of Township 94N Range 20W. Additionally, the existing tile is undersized based on the current recommended drainage coefficient.

CAPACITY ANALYSIS

The standard design method for sub-surface tile drains utilizes drainage coefficients. The drainage coefficient is the rate at which water can be removed and is expressed as the equivalent depth of water covering the design area that can be removed in 24 hours. Because the existing tile is a private line, no profile was on file with the district history. However, during the survey of the existing tile, the outlet and intakes along the private tile were documented and used to determine an approximate grade. The calculated drainage coefficient for the existing private tile is between 1/16 inch and 1/8 inch per day. However, because the theoretical drainage coefficient is calculated using the size, grade, and drainage area, the actual capacity of the tile systems could be considerably less due to factors such as material age, tile damage, tile blockages, sedimentation and joint displacement. Appendix B displays the tile estimated capacities for the private tile.

The current drainage standard is ½” per day with good surface drainage and up to 1” per day for depressional areas. It is recommended the landowners consider additional actions to gain a minimum of a ½” per day drainage coefficient for DD33 Lateral 9 with improvements to the open ditch and tile system.


III. PROPOSED REPAIR

OPEN DITCH IMPROVEMENT

Currently, the existing tile line being outlet into the Open Ditch are limited in both size and ground cover by the existing elevation of the open ditch and the existing culvert crossing 150th Street. Being able to improve the tile and better guaranty the longevity of the tile facilities depends upon having an outlet elevation lower than what is currently available. Additionally, the size and shape of the open ditch facility would also be made uniform. A proposed cross section with an 8-foot bottom and 2 to 1 side-slopes would allow for a deeper outlet while maintaining ditch stability without removing excessive amounts of soil. The open ditch would also have all debris removed within the top of banks. This debris would include but is not limited to trees within the right-of-way of the ditch and beaver dams. The spoil material would be uniformly leveled and shaped to a typical cross section with a relatively flat top (2% slope) that is 14-18 feet wide, adjacent to the ditch with a 10:1 back-slope onto the adjacent land. These leveled berms would be placed in locations that would minimize disturbance of existing farm buffer zones. Fertilizing and seeding of disturbed areas within the open ditch would be completed to further control erosion. Where needed, new CMP tile extensions would be placed at the ends of field tiles entering the open ditch and new CMP surface drains would be installed at required locations as well as replacing existing surface drains. Appendix C contains a cost estimate for this improvement option.

PROPOSED LATERAL 9 TILE IMPROVEMENT

If the open ditch improvement is approved, the existing private tile could be replaced with the appropriate sized Reinforced Concrete Pipe Tile at the correct grade to provide the ½” drainage coefficient or greater while also being installed at a depth to provide a minimum of approximately 3 feet of ground cover.

The proposed Lateral 9 tile is currently a private tile however, it serves at least 10 different landowners west of DD33 and outlets to the open ditch facility of DD33. Therefore, it would be prudent to make this tile a facility of the district as new Lateral 9.

Appendix C contains a cost estimate for the ½”, ¾”, and 1-inch drainage coefficient improvement options. These options were included in order to compare drainage coefficients if a drainage coefficient greater than ½” is desired. Appendix B contains the proposed tile sizes to provide the ½”, ¾”, and 1-inch drainage coefficient, and Appendix E contains a preliminary plan set that outlines the size, slope, and position of the proposed tile.

WORK LIMITS & DAMAGES

Landowners are entitled to full reimbursement for damages resulting from the work on their lands outside of the district right-of-way. These damages will be established at a project completion hearing after the work is complete. The contractor will be assigned temporary work limits along each side of the ditch and tile lines to allow for construction activities. The work limits for the open ditch will be set at approximately 35 to 50 feet outside of the toe of the spoil pile of the ditch and tile limits would be set at approximately 40 to 65 feet on either side of the tile centerline.

It is anticipated that the work will commence in the late summer of 2019 and continue into the fall of 2019. Crops that are damaged during construction would be paid for by the District based on crop appraisals. The construction zone would be minimized and the work scheduled


to minimize the loss of crops.

Buffer Strips may exist within the work area. Seeding of these areas is typically performed by the landowner with reimbursement being made at the project completion hearing. Seed mixes for these lands is often very specific for the type of conservation practice which is utilized.

ROAD CROSSINGS

There are three road crossings and one railroad crossing included in the proposed project. All three of the road crossings (150th St., 160th St., & 170th St.) are controlled by the Cerro Gordo County Secondary Roads Department and the railroad line is owned by the Union Pacific Railroad.

The proposed 150th Street (B60) crossing would be sized to provide the desired drainage coefficient. This crossing would also be sized to provide an outlet through the road for all the tile facilities that currently outlet into the existing culvert under 150th Street. This would allow for additional tile improvements throughout the district without the need to construct through 150th Street again. The cost of this crossing would be paid by the Cerro Gordo County Secondary Road Department as required by Iowa Code.

The proposed 160th Street and 170th Street (B55) crossings would be sized to provide the desired drainage coefficient for the proposed Lateral 9. Similarly, the cost of these crossings would be paid by the Cerro Gordo County Secondary Road Department.

These crossings could be installed by either open cut or jack and bore. Open cut installation would be less expensive, but would require pavement removal on 150th Street and would require additional traffic control on all routes. Jack and boring these crossings would be more expensive, but would require far less disturbance of the existing roads. The cost estimates have calculated the cost of jack and bore for 150th Street and open cut for 160th Street and 170th Street.

The crossing on the railroad tracks would be bored to avoid interfering with the operation of the line.

IV. OPINIONS OF PROBABLE COST

The cost estimate for the repair option is contained in Appendix C. This estimate represents our best judgment of the probable cost based upon our experience with similar projects. The quantities and unit costs for construction are believed to be reasonably accurate for use in this report and hearing. Actual costs are subject to the market for the respective components and to other economic forces. These estimates carry no actual or implied guarantees.

V. DISTRICT RIGHT-OF-WAY

Open ditch right-of-ways are essential to maintaining district quality and efficiency. These right-of-way purchases include the right of ingress and egress across adjoining land and the right of access for maintenance, repair, improvement, and inspection. A review of the existing right-of-way for DD33 Open Ditch was performed, starting with the district history found at the Cerro Gordo County Courthouse. No claims for damages caused by the taking of land for the right-of-way for the open ditch were found. Therefore, the landowner records for each


parcel of land along the open ditch were examined for the existence of right-of-way. From this review, it was determined that a right-of-way width has not been defined.

Under Iowa Code Section 468.27 Dismissal or Establishment – Permanent Easement – second paragraph “Following its establishment, the drainage district is deemed to have acquired by permanent easement all right-of-way for drainage district ditches, tile lines, settling basins and other improvements, unless they are acquired by fee simple, in the dimensions shown on the survey, plat and profile, if one is made.” And also under section 468.126 Repair, Subsection 8 – “If the drainage records on file in the auditor’s office for a particular district do not define specifically that land taken for right-of-way for drainage purposes, the Board may at any time upon its own motion employ a land surveyor to make a survey and report of the district and actually define the right-of-way taken for drainage purposes.” Typically, it is necessary to have a minimum width of right-of-way to contain the top width of the ditch and to have 20 feet on each side of the ditch for access. The current top width of the open ditch is approximately 40 feet. Therefore, to provide 20 feet on each side of the ditch would necessitate a width of right-of-way of 80 feet.

Drainage district open ditch right-of-ways are exempt from real estate taxes and drainage assessments. Therefore, deductions should be made to the net acres of those affected parcels and the property records for those affected parcels should be adjusted accordingly. It is recommended 80 feet be established as the width of record and their acres exempt from taxation adjusted accordingly. Under Iowa law, landowners have the right to the beneficial use of the spoil bank in the right-of-way subject only to the district’s use of the right-of-way to protect and maintain the open ditch. Appendix D has a tabulation of the acres of land required from each forty tract or fraction thereof as right-of-way.

VI. FARM PROGRAM COMPLIANCE

Farm Program Wetland Conservation Rules

The farm program wetland conservation rules are administered by the USDA Farm Service Agency. The USDA Natural Resources Conservation Service provides technical assistance. This technical assistance includes policing for program violations and making certified wetland determinations. At the time of the filing of this report, we will have not made requests of landowners receiving benefits from the proposed improvements to secure certified wetland determinations from the USDA/NRCS and to provide them to the district. Only landowners or their authorized agents may request the determinations from the USDA. Most landowners will have valid wetland determinations in their USDA files. If the improvement option is approved, wetland determinations will be needed for all of the agricultural or potentially agricultural land in the district.

The USDA has in recent years adopted a few revised interpretations of the farm program wetland conservation rules which are applicable here.

● For any improvements constructed by a drainage district, the NRCS will make a rebuttable assumption that every farmed wetland in the drainage district will be converted. (This assumption can be appealed by the impacted landowners, but not by the drainage district.

● Mitigation of converted farmed wetland must compensate for all lost wetland functions and must also be made at a minimum acre for acre basis.


● A plan for the mitigation of all converted farmed wetland in the drainage district must be approved by the NRCS prior to the beginning of the construction of the improvements. After all opportunities for appeals are exhausted, the farmed wetland not covered by that mitigation plan would be found converted and the landowner and tenant would be in technical violation of the farm program. Penalties can be avoided when a drainage district causes the conversion but only at the price of abandoning farming of the converted farmed wetlands or ceasing to participate in the farm program.

● The planned mitigation must be in place and functioning no later than the completion of the project which converts the farmed wetlands.

If a landowner does not provide a certified wetland determination and he happens to end up with a converted farmed wetland which he continues to crop, he will find himself in technical violation of the farm program rules and be subject to a USDA claim for the forfeiture and possibly refund of farm program payments when the work commences.

The boards of supervisors in Iowa may approve and authorize construction of the proposed improvements without accruing risk to the drainage district from farm program wetland conservation rules violations. Obviously, the board will want to know the wetlands status of all landowners and to help to keep them all in farm program compliance, but the board cannot allow the failure of an individual landowner to share wetland information to influence the very important decisions they are charged to make for all of the benefitted landowners. By the rules, the program penalties will fall solely to the owners of the converted farmed wetlands for which cropping continues and compensatory mitigation is not secured. It is then fully up to each landowner to cooperate with his drainage district toward keeping himself/herself in farm program compliance.

Converted Wetland Mitigation Alternatives

Since 1987, the USDA has assumed jurisdiction over the conversion (or improved drainage of) what has become commonly termed “farmed wetland”. It being the rebuttable assumption of the current USDA policies that all farmed wetlands will be converted and that acre-for-acre mitigation will be necessary to put the converted farmed wetlands back into production, the decision process is actually made a little easier—although mitigation is made costlier.

Mitigation options include the purchase of wetland credits in a mitigation bank. Mitigation banks are not very common and their credits are not cheap. New sites for mitigation are currently available from the Iowa Agriculture Mitigation Bank, Inc. (IAMBI). The current price for mitigation at the IAMBI is approximately $12,000 per acre.

Another alternative is for the district to self-mitigate, wherein a mitigation plan to use a suitable site inside or outside the district on which to create wetlands for mitigation of impacted wetlands is developed for review and approval by the NRCS.

A third alternative is to have the district pay the owner of a converted farmed wetland a portion of the cost for mitigation. The landowner may then either purchase mitigation on his own or let the land lay idle until mitigation is acquired.

Farm program rules clearly provide that when a farmed wetland is converted by a drainage district the conversion act is attributed to the owner of the farmed wetland. However, the farm program rules also clearly provide that the owner of the converted farmed wetland may remain eligible for farm program benefits by opting to not farm the converted farmed


wetland. If for some reason mitigation is delayed, this can be a temporary solution for the farmed wetland owners in a drainage district. It is also an option for those who choose not to provide certified farmed wetland determinations and end up with a converted farmed wetland.

Wetland Mitigation Policy

How drainage districts address mitigation is relatively new and a statewide standard practice has not yet evolved. This includes how the costs of the mitigation are paid. In several counties the mitigation costs have been shared between the district and the owners of the converted farmed wetlands, when wetland mitigation credits were available. In some counties mitigation has been left entirely to the owners of the converted farmed wetlands. Each drainage district’s circumstances are different and the boards of supervisors in other counties have exercised flexibility in addressing mitigation on a case by case and district by district basis.

In some other counties, the Board of Supervisors have adopted resolutions that spell out how farmed wetlands will be dealt with for drainage districts under their supervision when drainage improvements are considered.

The resolution provides that if an improvement project is authorized the drainage district will exercise the third mitigation alternative described above. The owners of all farmed wetlands known at the time of the hearing and which the USDA eventually determines will be converted by the drainage district project will be credited or paid up to $7,500 per acre of converted farmed wetland. This is intended to offset a part of the cost of mitigation.

In order to retain farm program eligibility, the converted farmed wetland owner may need to forego cropping of the converted farmed wetland until mitigation becomes available. In the future the landowner could purchase mitigation and resume farming of the converted farmed wetland, or opt to leave the converted wetland site permanently idle.

VII. CLEAN WATER ACT COMPLIANCE

Dredging and filling of “waters of the United States” (WOTUS) is regulated under Section 404 of the Clean Water Act. In the 1990’s the USEPA & USACE adopted rules to extend section 404 jurisdiction to isolated wetlands, including farmed wetlands. For a few years it became necessary to get CWA Sec 404 permits for drainage district improvements where farmed wetland conversions were expected. Drainage districts were helped at the time with the issuance of a memorandum of understanding entered into by 4 regulatory agencies. This agreement gave the NRCS primacy in mapping and regulating wetlands on agricultural land. Great relief came in 2001 when the U.S. Supreme Court ruled that isolated wetlands were not subject to CWA Sec 404 jurisdiction.

However, in 2012 the USEPA launched an aggressive rulemaking procedure to reestablish jurisdiction of isolated wetlands by revising the definition of “waters of the United States” (WOTUS) to include isolated wetlands. This massive rule change became effective on August 28, 2015. However, a temporary stay was imposed by the Sixth Circuit Court of Appeals in October 2015 and that stay remains in effect at this time and for an unknown period.

It is all but certain that if it were to be unleashed the WOTUS rule would 1) expand CWA Sec 404 jurisdiction to include all isolated farmed wetlands and even drained prairie potholes, 2) identify


more jurisdictional wetland than has the USDA identified under the farm program and 3) demand more stringent and costly mitigation for the conversion of farmed wetland. That is assuming drainage improvements will be allowed at all – a scary thought but one that is applicable from a plain reading of the CWA Section 404(b)(1) guidelines which requires proof of inability to avoid draining a wetland before it can be drained and mitigated.

We are reasonably confident that until the WOTUS rule stay is lifted there are no CWA Section 404 jurisdictional wetlands found in the benefited area and that only the farm program wetland rules are in play. In addition, the new EPA chief has announced that the EPA will abandon the WOTUS rule and launch a new rule-making effort. Hopefully that rule will be less intrusive for drainage district landowners in the prairie pothole region. However, the open ditch improvement will require the application for a permit from the Corps of Engineers and the Iowa DNR as well as local agencies.

VIII. WATER QUALITY

The hydrologic impacts to tile drainage entails a complex interaction of processes dependent upon landscape, climatic and human influences, watershed scale, soil permeability and rainfall event size. There is a popular and often accepted idea that an increase in subsurface drainage facilities adds to an increase in both peak and total rainfall values thereby increasing flooding. Recently published research from the University of Iowa’s IIHR – Hydroscience and Engineering Center refutes that perception. This University of Iowa report was the result of a water model study of the Clear Creek Watershed in Iowa and Johnson Counties and found that an increase in field tile and subsurface drainage decreases peak flows for most storm events. The field scale DRAINMOD model was used in the research in conjunction with a simplified routing equation to analyze the impact of tile drains in the Clear Creek Watershed.

However, additional steps are required to slow, impound, or infiltrate water in order to receive benefits in water quality. Water quality is a growing topic throughout the nation and more recently throughout Iowa. The particle loads and nutrient levels within drainage water is a concern that is receiving increased scrutiny. Processes and reduction practices are being developed and incorporated on farms and into projects throughout Iowa which reduce nitrogen loss and improve water quality. Enhancement of water quality is possible through many different drainage applications that can see both immediate and long term benefits.

We encourage the landowners of this District to consider multi-purpose drainage management, which incorporates Best Management Practices (BMPs) which utilize effective measures aimed at reducing sediment and nutrient loading, and improving water quality. These BMPs are divided into three (3) areas: preventative measures, control measures, and treatment measures.

Preventative measures that can be applied throughout the watershed include crop rotation, cover crops, residue management, and nutrient management. These measures are aimed at controlling sediment, minimizing erosion and nutrient loss, and sustaining the soils health, all without dramatically changing the current land use of the landscape.

Control measures are practices aimed at improving water quality directly associated with the flow of water by reducing peak flows, providing in stream storage, sedimentation, and nutrient uptake. Examples of control measures include alternative tile intakes, grassed waterways, two (2) stage ditches, water control structures, and controlled subsurface drainage. These practices are directly linked to the conveyance of subsurface tile water or open channel ditch flow.


The function of treatment measures is to improve water quality by directly removing sediment and nutrients from the subsurface or surface water flow throughout a watershed. Examples of treatment measures include surge basins (storage ponds), filter/buffer strips, wetland restorations, woodchip bioreactors, and water and sediment control basins (WASCOBs).

These practices may be incorporated to either the public or private drainage systems.

Funding options are available to land owners through the Environmental Quality Incentives Program (EQIP) and the Iowa Water Quality Initiative. EQIP is a voluntary program that provides financial assistance to individual land owners for various conservative practices as identified above. Also, the State of Iowa through the Iowa Water Quality Initiative provides cost share funds to participating landowners to voluntarily install nutrient reduction practices.

A unique opportunity may exist when a wetland is created within the district for the treatment of the tile and/or surface waters of the watershed. A properly sized and created wetland may be able to be utilized as a mitigation site for any farmed wetlands that are found within the drainage district. With the possibility of a large share of the created wetland being funded by the Iowa Water Quality Initiative program, any potential farmed wetlands could be mitigated at a much reduced cost.

If there is landowner interest in any of these water quality features and funding options, further study and review would be required to select, site and fund the water quality measures appropriate for the area.

IX. ANNEXATION

Upon the review of the existing watershed and assessment boundary, it was found that lands that are benefiting from the existing district facilities are not assessed for the benefit that they receive. Additionally, the petition specifically requests that additional drainage be provided for areas that aren’t currently part of DD33. Therefore, there are areas that were found to be benefiting from the existing district facility as well as areas that would only be benefited from the construction of an additional facility. The district plat in Appendix E shows the approximately 47.5 acres of land that are benefited by the existing facilities and the approximately 591.0 acres of land that would be benefited by the proposed facility. These lands are not currently assessed for benefit in any adjacent drainage district and should be added to the schedule of DD33. The Board of Supervisors are able to annex these lands under Section 468.119 of the Iowa Code states "...if the board becomes convinced that additional lands contiguous to the district, and without regard to county boundaries, are benefited by the improvement to said district as contemplated in Section 468.126, the board may adopt with or without a petition from owners of the proposed annexed lands, a resolution of necessity for annexation of such additional land."

We recommend annexation of all those materially benefiting areas as they have the specific benefits of being able to drain their land to the facilities of the district and have surface drainage which flows to the facilities of the district.

X. RECLASSIFICATION

If the Board approves the construction of the proposed Lateral 9 and the subsequent annexation of lands benefited Lateral 9, these lands will need to be classified. Additionally, because of the single district schedule, reclassification would be recommended for the remainder of the district to separate all district facilities onto separate schedules. This separation occurs because landowners


which only utilize one of the district facilities may be assessed for repairs to a lateral tile system which they may not utilize. Individual schedules would be prepared for the Open Ditch and all Branch Tiles. Lastly, if the improvement option is approved, reclassification is required as stated in Section 468.131 of the Iowa Code: “When an assessment for improvements…exceeds twenty-five percent of the original assessment and the original or subsequent assessment or report of the benefit commission as confirmed did not designate separately the amount each tract should pay for the main ditch and tile lateral drains then the boards shall order a reclassification.”

Additionally, even without the addition of Lateral 9, the current assessment schedule does not assess approximately 47.5 acres of “benefited” land. These 47.5 acres of land have not been paying for maintenance and repairs to the facilities of DD33 since the creation of the district even though these lands have materially benefited from said facilities.

XI. SUMMARY & DISCUSSION

This report has confirmed the need for drainage relief for Drainage District No. 33 The work described herein can accomplish that relief. We recommend proceeding with the Improvement Option. The proposed improvement is considered to be of public benefit and are conducive to the public health, convenience or welfare.

Recommendations

Open Ditch & Lateral 9 Improvements Recommended

The existing private tile that outlet to the Open Ditch is shallow, damaged, and undersized based on today’s drainage standards and need improvement. This private tile acts as a district facility and drains lands that are not currently included in any other drainage district. Therefore, it is recommended that this facility be constructed and adopted into Drainage District No. 33. However, this improvement would only be possible if the Open Ditch is also improved. Additionally, any areas of damaged side-slopes and surface drain pipes would be repaired. Rusted and damaged CMP tile extensions should be repaired. The proposed improvements are considered to be of public benefit and is conducive to the public health, convenience or welfare.

Right-of-Way Recommended

Because the existing right-of-way is not currently defined, it is recommended that right-of-way be established as 40’ each side of centerline in order to facilitate maintenance of the Open Ditch now and into the future.

Annexation Recommended

Approximately 47.5 acres of lands within the watershed materially benefit from the existing facilities of DD33 but have not been assessed for the maintenance of those facilities. Additionally, if Lateral 9 is approved, 591.0 acres would benefit from the construction of Lateral 9. In order to fairly distribute the costs of future maintenance, as well as any repair or improvements, it is recommended that the annexation procedure be implemented.

Reclassification Recommended

There are material inequities in the current assessment schedule used by the district. A single schedule exists for all facilities within DD33. This schedule does not account for lands that only use a select portion or length of facility. This single schedule requires landowners to pay for repair on facilities that they have never used, and will never use. Additionally, if Lateral 9 is constructed it will need to be classified to determine benefit for construction and all future maintenance costs. The Iowa Code Section 468.65 states: “When, after a drainage or levee


district has been established… or when a repair, improvement, or extension has become necessary, the board may consider whether the existing assessments are equitable as a basis for payment of the expense of maintaining the district and of making the repair, improvement or extension. If they find the assessments to be generally inequitable they shall order a reclassification of all property subject to assessment.”

Installment Payments

Iowa drainage law allows for drainage district costs for large projects to be spread over between ten to twenty years at the discretion of the Board of Supervisors. Typically, the board would spread assessments of the magnitude contemplated in this report over twenty years. Be reminded that final individual assessments are based upon benefits and that some parcels will likely bear two to three times the average per acre costs.

Recommended Steps

It is recommended that the Board of Supervisors acting as trustees for Drainage District No. 33 take appropriate action, with legal guidance, to accomplish the following:

1. Tentatively approve this engineer’s report and schedule a public hearing to receive and

consider the input of the district landowners.

2. Adopt the improvement alternate recommended for construction, modified as deemed

appropriate, to satisfy the desires of the District.

3. Establish a uniform width of ROW and direct the Assessor to make the necessary

adjustments in property records.

4. Direct the engineer to prepare final plans and specifications for the adopted plan and

proceed toward a bid letting.

5. Initiate annexation of benefited lands not on the assessment schedule. A separate

report on annexation and public hearing on the annexation report would be required.

6. Initiate reclassification of benefits for DD33. A separate commissioners’ report on

reclassification and public hearing on commissioners’ report would be required.

Respectfully submitted, Bolton & Menk, Inc. Kent L. Rode, P.E. Senior Project Manager

Appendix A: Petitions

Appendix B: Tile Capacities

1/2"

Dra

inag

e

Co

effi

cie

nt

3/4"

Dra

inag

e

Co

effi

cie

nt

1" D

rain

age

Co

effi

cie

nt

10+

00

28+

69

12

0.54

00.

012

0.00

54

0.7

93

.14

0.2

52

.84

75

9.3

0.0

89

17.8

%2

42

73

0

228

+69

65+

44

12

0.40

00.

012

0.00

40

0.7

93

.14

0.2

52

.45

70

0.0

0.0

83

16.6

%2

43

03

6

365

+44

96+

23

12

0.50

00.

012

0.00

50

0.7

93

.14

0.2

52

.74

43

8.6

0.1

49

29.7

%2

12

42

7

P (

ft)

A (

ft)

S (f

t/ft

)n

Gra

de

(%)

DIS

TRIC

T FA

CIL

ITY

CA

PA

CIT

Y

DR

AIN

AG

E C

OEF

FIC

IEN

T

DR

AIN

AG

E D

ISTR

ICT

NO

. 33

CER

RO

GO

RD

O C

OU

NT

Y, I

OW

A

Req

uir

ed S

ize

For:

Exis

tin

g P

riva

te T

ile C

apac

ity

Segm

ent

Stat

ion

Sta

rtSt

atio

n E

nd

Size

(in

)%

of

1/2"

Co

effi

cie

nt

Dra

inag

e C

oef

fici

en

t (i

n/d

ay)

Dra

inag

e A

rea

Flo

w C

apac

ity

(cfs

)R

(ft

)

1/2"

Dra

inag

e

Co

effi

cie

nt

3/4"

Dra

inag

e

Co

effi

cie

nt

1" D

rain

age

Co

effi

cie

nt

19+

83

10+

75

34

0.43

00.

012

0.00

43

6.3

18

.90

0.7

14

0.7

91

44

8.3

0.6

70

134.

1%3

43

64

0

210

+75

19+

90

24

0.43

00.

012

0.00

43

3.1

46

.28

0.5

16

.11

76

4.6

0.5

02

100.

3%2

43

03

3

319

+90

38+

72

24

0.45

00.

012

0.00

45

3.1

46

.28

0.5

16

.48

72

7.9

0.5

39

107.

8%2

43

03

3

438

+72

58+

15

24

0.55

00.

012

0.00

55

3.1

46

.28

0.5

18

.22

70

0.0

0.6

20

123.

9%2

42

73

0

558

+15

62+

36

21

0.50

00.

012

0.00

50

2.4

15

.50

0.4

41

2.1

74

92

.60

.58

811

7.6%

21

24

27

662

+36

74+

55

21

0.40

00.

012

0.00

40

2.4

15

.50

0.4

41

0.8

94

91

.50

.52

710

5.4%

21

24

27

774

+55

84+

24

21

0.35

00.

012

0.00

35

2.4

15

.50

0.4

41

0.1

84

38

.60

.55

311

0.5%

21

24

27

884

+24

100

+07

15

0.57

00.

012

0.00

57

1.2

33

.93

0.3

15

.30

24

9.6

0.5

05

101.

0%1

51

82

1

910

0+0

71

05+1

41

20.

580

0.01

20.

005

80

.79

3.1

40

.25

2.9

51

40

.00

.50

110

0.2%

12

15

18

10

105+

14

120

+33

12

0.68

00.

012

0.00

68

0.7

93

.14

0.2

53

.19

13

5.5

0.5

61

112.

1%1

21

51

5

11

120+

33

129

+82

12

1.20

00.

012

0.01

20

0.7

93

.14

0.2

54

.24

53

.21

.89

737

9.3%

12

12

12

12

129+

82

131

+23

12

1.60

00.

012

0.01

60

0.7

93

.14

0.2

54

.90

33

.03

.53

170

6.2%

12

12

12

13

131+

23

133

+06

12

2.00

00.

012

0.02

00

0.7

93

.14

0.2

55

.47

28

.84

.52

390

4.7%

12

12

12

Flo

w C

apac

ity

(cfs

)

DIS

TRIC

T FA

CIL

ITY

CA

PA

CIT

Y

DR

AIN

AG

E C

OEF

FIC

IEN

T

DR

AIN

AG

E D

ISTR

ICT

NO

. 33

CER

RO

GO

RD

O C

OU

NT

Y, I

OW

A

Pro

po

sed

Lat

era

l 9 C

apac

ity

Segm

ent

Stat

ion

Sta

rtSt

atio

n E

nd

Size

(in

)G

rad

e (%

)n

S (f

t/ft

)A

(ft

)P

(ft

)R

(ft

)D

rain

age

Are

aD

rain

age

Co

effi

cie

nt

(in

/day

)%

of

1/2"

Co

effi

cie

nt

Req

uir

ed S

ize

For:

Appendix C: Opinions of Probable Cost

Item Unit Quantity Unit Price Total

Open Ditch Excavation CY 1,895 $5 $9,475

Spoil Bank Leveling (Two Sides) STA 8 $200 $1,600

Seeding & Fertilization Open Ditch STA 8 $500 $4,000

Geotextile Fabric SY 115 $3.50 $403

Riprap TN 95 $45 $4,275

Fence Cuts EA 3 $1,000 $3,000

Mobilization LS 1 $1,100 $1,100

Construction Contingency LS 1 $2,147 $2,147

Main Open Ditch Improvement $26,000

Item Description Unit Quantity Unit Price Total

Lateral Tile Connections, 10" Dia or Smaller EA 12 $300 $3,600

24" Dia. R.C.P. Elbow Section, Fabrication Only EA 6 $450 $2,700


15" Dia. R.C.P. Elbow Section, Fabrication Only EA 2 $300 $600


Exploritory Excavation HR 8 $150 $1,200

Trench Foundation and Bedding TN 850 $30 $25,500

Drain Tile, Trenched, 2000D R.C.P., 24" Dia. LF 4,643 $38 $176,434




Drain Tile, Trenchless Steel, 0.40625" Wall, 26" Dia. LF 100 $600 $60,000

SW 401N Manhole 96" Dia. EA 1 $12,500 $12,500

Fence Cuts EA 6 $1,000 $6,000

Silt Fence, Installation and Removal LF 100 $5 $500



Lateral 9 Tile Improvement $589,000

Engineer's Opinion of Probable Cost

Main Open Ditch & Proposed Lateral 9

Facility Improvements

Drainage District No. 33

Cerro Gordo County, Iowa

2019

Estimated Construction Costs 0.50" Drainage CoefficientMain Open Ditch Improvement

Description

Proposed Lateral 9 Tile Improvement






2019



Traffic Control LS 1 $1,500 $1,500




Lateral 9 Tile Improvement - 150th Street $71,500

Trench Foundation and Bedding Stone TN 7 $30 $210

Trench Compaction Testing LS 1 $1,000 $1,000

Drain Tile, Trenched, 3000D RCP, 21" Dia. LF 66 $35 $2,310



Mobilization LS 1 $300 $300

Construction Contingency LS 1 $680 $680










Total Estimated Project Construction Cost $699,200

Proposed Lateral 9 Tile Improvement - Work in County Road Right-of-Way

150th Street - Bored

160th Street - Open Cut







2019

Construction Related Damages $6,000

Basic Engineering Services

Survey, Study & Report. Meetings & Hearing $20,000

Annexation $5,000

Reclassification $20,000

Construction Plans, Specifications, & Bid Letting $50,400

Construction Engineering Services, Staking, and Inspection $54,200

Legal Services, Publications, Mailings, Etc.. $1,500

Finance, Interest & Contingency $34,600

Total Estimated Assessable Project Cost $890,900

Open Ditch Average Cost Per Acre $40

Proposed Lateral 9 Average Cost Per Acre $970

Estimated Non-Construction Costs






Riprap TN 95 $45 $4,275

Fence Cuts EA 3 $1,000 $3,000





















Fence Cuts EA 6 $1,000 $6,000










2019

Estimated Construction Costs 0.75" Drainage CoefficientMain Open Ditch Improvement

Description







2019


































2019




Annexation $5,000






Total Estimated Assessable Project Cost $986,602


Proposed Lateral 9 Average Cost Per Acre $1,090







Riprap TN 95 $45 $4,275

Fence Cuts EA 3 $1,000 $3,000

















Drain Tile, Trenched, 2000D R.C.P., 18" Dia. LF 507 $33 $16,731





Fence Cuts EA 6 $1,000 $6,000










2019

Estimated Construction Costs 1" Drainage CoefficientMain Open Ditch Improvement

Description







2019


































2019




Annexation $5,000






Total Estimated Assessable Project Cost $1,055,400


Proposed Lateral 9 Average Cost Per Acre $1,170


Appendix D: Right-of-Way Tabulation

80.00

SIMON,JAMES M

COBB, DAVIDLLOYD & NETT,

LISA ANNSIMON,JAMES M

FERN HARMONFAMILY, LLC

150TH ST

Drainage District No. 33Cerro Gordo County, Iowa

Right-of-Way MapMa

p Doc

umen

t: H:\C

ERRO

GIA\P

1311

5455

\GIS\

ESRI

\ROW

_Plat

.mxd

| Date

Save

d: 2/1

1/201

9 9:56

:13 AM

Legend!I

Proposed Ditch ROWDitch CenterlineParcelsWatershed

0 100Feet

Source:

Landowner Parcel ID Section-Township-Range Legal Description

Total

Established

Width (ft)

Proposed

ROW (ac)

COBB, DAVID LLOYD & NETT, LISA ANN 150820000700 8-T94N-R20WPCL "B" LOC IN NE1/4 08-94-

20 BEG AT SE COR NE1/4*80 1.49

Total 1.49

Open Ditch Right-of-Way



Appendix E: Preliminary Plans

engineer’s report drainage district no. 33

Documents