Engage 2045 -Future Growth’s Environmental Impact on James City County’s Watersheds

“Growth is not a certainty like death and taxes but in James City, it is not likely to be a passing fad, either.”

Jack Edwards, Chairman James City County Board of Supervisors 1985

James City County is on a precipice; that a continuation of past zoning and land use policies will bring about a fiscal, economic and environmental crisis long before 2045

Executive Summary

As James City County embarks upon another revision of its Comprehensive Plan – Engage 2045 – the Hampton Roads Transportation Planning Organization Traffic Analysis Zone (TAZ) model projects that county population will increase by 60% from today’s 76,000 to 120,741 in 2045. This places the county on a precipice, facing a fiscal, economic and environmental crisis long before 2045 unless zoning and land use policies are changed significantly.

For the first time, this revision process will include likely growth scenarios for the county in the next thirty years by utilizing the Hampton Roads Transportation Planning Organizations Model and its three components – the Traffic Demand Model, a Land Use Model, and the Transportation Economic Model, TREDIS.

Five of the Citizen Survey questions show a significant gap between the following issues that citizens deem important and with which they are not satisfied. All are interwoven with population growth. While this paper will address two of those issues – preserving the rural character and protecting the environment – all five of these gap areas should be considered as we evaluate the efficacy of the three growth scenarios.

Affordable housing – 33% gap (83% important vs. 50% satisfied)
Roads & highways – 24% gap (98% important vs. 74% satisfied)
Attracting jobs& businesses – 20% gap (88% important vs. 68% satisfied)
Preserving rural character – 16% gap (85% important vs. 69% satisfied)
Protecting environment – 15% gap (85% important vs. 70% satisfied)

If citizens are not satisfied now, they will be less so if no changes are made to the county’s land-use policies.

The TAZs data projects 2045 population, households, and vehicle trips which overlay at the sub-watershed level. These, along with new buildings, homes, roads, driveways, and parking lots, allow us to project future increases in impervious cover and to assess the cumulative impact on the county’s environment and rural character. To date that impact has not been cheap: the county has spent about $9.4M from 2008- 2015 and plans to spend another $21.3M over the next five years. Without a significant change in the county’s growth policies, these costs are certain to grow. This paper will examine the current and future land usage for economic development and the impact that usage had and will have on the county’s environment and rural character.

TAZ projections show a very high population and impervious surface growth in the Yarmouth Creek, Skimino, Ware Creek, and the Diascund Creek watershed driven by the buildout of the Barhmasville 227 Interchange and the Toano- Anderson Corner Economic Opportunity Areas, among other areas.

The Skimino Creek and Yarmouth watersheds will also be subject to rapid population growth if the Hill Pleasant Farm/Mooretown Road Economic Opportunity Area is buildout. Immediately to the east, York County’s portion of Lightfoot is also undergoing a rapid transition from farmland to apartments, single-family residential, and commercial. The impacts on both Skimino and Yarmouth watersheds from increased impervious cover with the corresponding loss of forest and agricultural lands coupled with the current and future traffic congestion from economic and residential development by both James City and York County in the same area requires a re-examination of why the Mooretown Road/Hill Pleasant Farm Area is designated as an economic opportunity area in the Engage 2045 Comprehensive Plan.

There are opportunities that the watershed paper discuss and there are set of consistent themes throughout each of the watershed papers –

Conservation and preservation programs protect the ecosystem services that our watershed provides for wildlife and plant habitat.

Each section talks about the PDR, AFD, and other conservation programs’ contributions and their cost to conserve and protect the environment and rural character. Between 1997 and 2016 the county spent $30.1M on 27 PDR and Green-space projects placing 2,035 acres in a conservation easement of one type or another. ( Mill AFD/PDR, Powhatan AFD/PDR, Yarmouth AFD/PDR, Gordon AFD/PDR, Skimino AFD/PDR, Ware AFD/PDR )

There are significant areas of the Gordon, Yarmouth and Ware Creek that are rated as outstanding and very high for their environmental and ecologically habitat by the Commonwealth.

There is a section on Ecotourism as an economic opportunity for the Lower Chickahominy. It says “in James City County for every $1.00 spent annually in the provision of public services to support land with conservation easements, revenues to James City County were estimated to be $1.53.”

There is a look at the three economic opportunity areas form the 2035 Comp Plan and suggests a land-use change for the Mooretown/Hi Pleasant Farm EO areas. There is a caution and need for balance as the Barhamsville Interchange and the Toano/Anderson’s Corner EO Areas are developed with a review of current zoning and land-use policies surrounding these EO areas.

Sea-level rise will alter the future freshwater tidal ecosystem of the six watersheds. There is an inland migration of their marshlands, changes to resource protections areas, and increased salinity levels. Mill Creek, Powhatan Creek, Yarmouth Creek, Gordon Creek, Skimino Creek, and Ware Creek.

The combination of sea-level rise and the increasing amount of rainfall may increase incidents of flooding along the Powhatan Creek Watershed

The last paper, Engage 2045 – So What? is a proposal that the Engage 2045 Comprehensive Plan develops a County Watershed Map overlaid on the 2045 Comprehensive Land Use Map. There is the suggested consideration of a Watershed-zoning chapter addition to Chapter 8 Erosion and Sediment Control, Article II Virginia Stormwater Management Program county ordinance. The paper designate sub-watershed areas within a watershed that are environmentally sensitive areas with recommended impervious cover ceilings that would form the basis of the County Watershed Map overlay on the Comprehensive Land Use Map.

Introduction

James City County has embarked on an update of the county’s next Comprehensive Plan – Engage 2045. The process for the first time is attempting to examine likely growth scenarios for the county in the next thirty years by utilizing the Hampton Roads Transportation Planning Organizations Model. The model has three components – the Traffic Demand Model, a Land Use Model, and the Transportation Economic Model, TREDIS.

The model has the ability to asses a likely growth scenario’s cumulative impact in terms of traffic congestion and the cumulative cost of county support services.

The model does not appear to provide a cumulative impact on the environment or a cumulative impact on the rural character.

The intent of this series of papers is to describe the quantitative impact on the environment and by inference, the qualitative impact on the rural character as well as community character. As a result, we may identify opportunities that will close the gap between important and satisfied. The six individual watershed analysis are here below –

Mill Creek Watershed
Powhatan Creek Watershed
Yarmouth Watershed
Gordon Creek Watershed
Ware Creek Watershed
Skimino Creek Watershed

The Three additional paper are here –

Engage 2045 – JCC’s 3 Economic Opportunity Zones Development and 2045 population growth.
Engage 2045 – Economic Development, Preserving the Rural Character and Protecting the Environment thru Ecotourism
Engage 2045 – So What?

The quantitative measures are from the six county’s watershed management plans. The data maps the relationship between growth and its relationship to an increasing percentage of impervious surface in a watershed with its impacts on aquatic systems, hydrology, habitat structure, water quality, and biodiversity.

The intended purpose of these papers is to describe the quantitative impact on the environment and by inference, the qualitative impact on the rural character as well as community character. As a result, we may identify opportunities that will close the gap between important and satisfied. starts with the Mill Creek and Powhatan Creek Watersheds as the most developed and which have the highest percentage of impervious cover in the county. The next two in the series are the Gordon and Yarmouth Creek Watersheds which are the least developed to have the lowest percentage of impervious cover. The Ware and York/Skiminio Watersheds are potentially on the brink of increased development in the next thirty years and both have low percentages of impervious cover.

Along with this is an assessment of the three Economic Opportunity Zones in the 2035 Comprehensive Plan.

The county Watershed Management Plans provide an environmental assessment and paired with the Transportation Analysis Zones (TAZ) from the Traffic Demand Model. The TAZ socio-economic data is focusing on population, households and vehicles increases between 2015 and 2045. This socio-economic data is used as a measure of the projected build-out of an area based on the comprehensive plan and indicates the level of increased acres of impervious surface in a particular watershed.

Impervious surfaces consist of two primary components: the rooftops under which we live, work and shop, and the transport system (roads, driveways, and parking lots). Increasing amounts of impervious surface will have an adverse impact on the health of the watershed (Figure 1)

The Impervious Cover Model (Schueler, 1994) Figure1, classifies any watershed with between 10 percent and 25 percent cover as IMPACTED, which means runoff from urbanized areas is triggering stream channel and stream bank erosion. This degrades in-stream habitat such that biodiversity decreases. Any watershed with greater than 25 percent impervious cover is considered to be NON-SUPPORTING, which is typically characterized by severe stream channel and bank erosion, further degradation in-stream habitat, high nutrient and sediment loads, and bacteria levels that may prohibit recreational activities.

The three watershed plans were developed between 2001 and 2008 and the other three between 2011 and 2018. They are a historical record of the impacts of growth for a county. In 1980 the county had a population of 22,763, today a population of 76,397 and a projected 2045 population estimated at 120,741.

The watershed plans are in fact management strategies to mitigate the impacts of growth, increasing levels of impervious cover and to protect future water quality.

For those watersheds in the Sensitive 0-10%, impervious strategies employed ranged from zoning, site impervious restrictions, stream buffers, and stormwater practices that were applied to maintain predevelopment stream quality.
For those watersheds that are Impacted in the 11%-25%, range strategies were applied that mitigated impacts to the greatest extent possible, by employing effective stormwater management practices.
None of the county’s watersheds are in the No-Supportive range above 25% impervious surface cover

To mitigate the effects of increasing levels of impervious surface cover the county-funded between 2008 -2015 104 project for stream restoration, water quality improvement, retrofits, and outfalls at a total cost of $8,313,918.

In the FY 20-24 Capital Investment Program (CIP) there15 projects for stream restoration, water quality improvement, drainage improvement, water quality upgrade, and retrofit over a five year period at a total cost of $12,544,000.

In 2016 the county initiated a Neighborhood Drainage program to assist Home Owners Association with the maintenance of their stormwater facilities. 32 Neighborhoods participate with 57 projects over the last three years. The county’s matching share was $473,435 with a total cost of the 57 projects of $1,112948. An additional 25 projects are identified for funding in 2019.

From 2008 to 2024 the county will have spent $21,331,353 to mitigate the effects of growth on her watershed.

The six watershed plans besides being a historical record of the impacts of growth provide are a baseline for what future impacts growth will have on our watersheds. If a future aspiration for the county is to preserve the rural character and protect the environment, management strategies are required to prevent any meaningful degradation to Sensitive impervious levels or in those areas that are already Impacted continue to with those mitigation strategies. There are parts of our watershed that are in the 0.1%-0.3% impervious range that are described as “nearly pristine” and representing some of the most impressive fresh tidal vegetation in the Mid Atlantic.” There are future opportunities to protect and preserve and at the same time manage the growth that is not inevitable but no a passing fad.

The development of the new Comprehensive Plan is also about balance and management of growth. The new tools that will be used to develop the 2045 Comp Plan by the examination of likely growth scenarios require that balance of weighing how we preserve the rural character and preserve the environment of the county.

A little about the format for each of the six watershed papers. The intro you just read is the same for all six papers. All of the papers have this outline –

Watershed Overview
A discussion of the significant sub-watersheds with its accompanying TAZ data.
An Assessment Summary of Impervious Surface for the Watershed
A Summary Assessment and Conclusion
A 1.5 ft Sea Level Rise discussion for the watershed
A section called “Stay the Course” which discuss the policies and programs that are working centered around the AFD, PDR an Other Conservation Easement Programs
A section on “Opportunities” for the watershed
And a Closing paragraph

The reference documents used, are at the end and as a note, most of what is written in these papers is a direct lift or a paraphrasing of the specific watershed plans.

Engage 2045 – Mill Creek Watershed

Mill Creek Watershed Overview

The Mill Creek watershed is approximately 5.7 square miles in extent. It is 61 percent urbanized and, based on zoning information, it is close to its maximum level of development and is the most developed of all watersheds.

A substantial 27% (973 acres) of the Mill Creek watershed Figure 2 below) lies within a Resource Protection Area (RPA), with 26% of the watershed being forested.

Figure 2 Mill Creek Watershed Impervious cover Structures and Roads in red, RPAs in green and conservation easements in tan and purple

The majority of the impervious cover in the Mill Creek watershed is associated with neighborhoods populated by single-family homes, and 71 subdivisions are present and are concentrated in the northern two-thirds and in non-tidal areas, with the dividing line roughly coincident with Lake Powell Road (SR 618).

As a whole, 15.3 percent of the Mill Creek watershed is covered by 553 acres of impervious surfaces, including roads, buildings, parking lots, and other features such as recreational courts. However, 81 percent of these surfaces are located within the northern two-thirds of the watershed, which consists of four separate sub-watersheds – 201, 202, 203, and 204 (Figure 3)

Figure 3-Mill Creek Watershed with Sub-watersheds 201, 202, 203, and 204

The Mill Creek Traffic Analysis Zones (TAZs) (Figure 4) for the Mill Creek Watershed are below and the sub-watersheds 201,202, 203, and 204 correspond roughly to TAZs 1844, 1811, 1845 and 1810 respectfully. When taken as a whole the TAZs for the Mill Creek Watershed provides an insight into the future state of the watershed in 2045 in-terms of forecasted Population, Household, and Vehicles (Figure 5)

Figure 5 – Future state of the watershed in 2045 in-terms of forecasted Population, Household and Vehicles

Assessment of Impervious Surface for the Powhatan Creek Sub-watershed 201, 202, 203, and 204

Impervious cover within these sub-watersheds ranges from 18.8% to 26.4%. The Impervious Cover Model (Schueler, 1994) classifies any watershed with between 10 percent and 25 percent cover as IMPACTED, which means runoff from urbanized areas is triggering stream channel and stream bank erosion. This degrades in-stream habitat such that biodiversity decreases and most sensitive fish and aquatic insects cannot tolerate the conditions.

Three of the four sub-watersheds in the upper Mill Creek watershed (202, 203, and 204, (Figure 3) fall into this category.

Any watershed with greater than 25 percent impervious cover is considered to be NON-SUPPORTING, which is typically characterized by severe stream channel and bank erosion, further degradation in-stream habitat, high nutrient and sediment loads, and bacteria levels that may prohibit recreational activities. Sub-watershed 201 falls into this category.

Sub Watershed 201 Figure 6

Total impervious cover is 64.9 acres or 26 percent. Approximately half of the impervious cover is represented by roads and parking lots

Pollutant loading is forecast to change very little from existing conditions. Approximately 3 acres, or 1% of the sub-watershed, of open urban land and forest, is projected to be developed as residential land use. Residential subdivisions within the sub-watershed include the Foxes, Westray Downs, Baron Woods, Brandon Woods, and Village Square (Figure 7). The Governor’s Green Shopping Center and the John Tyler Commercial Park are also located in the sub-watershed and represent significant concentrations of impervious surfaces. Given that this is a small number of acres relative to the area of the sub-watershed and the fact that 26% of the sub-watershed is already impervious, it is likely that future development will have little impact on the subwatershed’s pollutant loads.

Figure 7 – TAZ 1844 & 201 Sub-watershed with Impervious cover Structures and Roads in red, RPAs in green.

Sub-watershed 202

Sub-watershed 202 is the largest sub-watershed in the Mill Creek watershed at 895.2 acres (Figure 8). It represents the upper non-tidal main stem of Mill Creek. Route 199 bisects the far northern portion of the sub-watershed. (Figure 6)

The impervious coverage is substantial, comprising 19% of the total area (168 acres), it is actually the least impervious of the four evaluated sub-watersheds. However, this degree of imperviousness still falls within the Impacted category on the Impervious Cover Model

Figure 9 – TAZ 1811 202 Sub-watershed with Impervious cover Structures and Roads in red, RPAs in green.

About 59 acres (7%) of the sub-watershed is zoned as business or business/industrial, with the vast majority of the area (829 acres) being zoned as residential. Residential subdivisions within the sub-watershed include The Foxes, Westray Downs, The Meadows, Mill Creek Landing, Jamestown Farms, Indigo Park, Graylin Woods, White Oaks, Canterbury Hills, Brook Haven, and The Midlands (Figure9). Ironbound Road Mini Storage is located at the head of Mill Creek, and some small business space is provided in The Midlands off Strawberry Plains Road in the northeast corner of the sub-watershed. Pollutant loading is forecast to change very little from existing conditions. Approximately 15 acres, or 2% of the sub-watershed, of open urban land and forest, is projected to be developed as residential land use. Given that this is a small number of acres relative to the area of the sub-watershed and the fact that 19% of the sub-watershed is already impervious, it is likely that future development will have little impact on the subwatershed’s pollutant loads

Sub-Watershed 203 Figure 10

Subwatershed 203 (Figure 8 is 406 acres in size with 83 acres (20%) of impervious cover, placing it in the Non-Supporting category of the CWP’s Impervious Cover Model. John Tyler Parkway crosses through the northwestern portion of the watershed. Only 10 acres of sub=watershed 203 consist of wetlands while 55 acres are included as RPA. The vast majority of the sub-watershed is zoned as residential, though there is a considerable area (81 acres or 20%)zoned for businesses located in the north. Residential subdivisions within the sub-watershed include Marywood, Kingswood, Hollybrook, Druid Hills, Indigo Park, La Fontaine, and Winston

Terrace. The Williamsburg Crossing commercial area and a Riverside medical facility are also located in the sub-watershed.

Pollutant loading is forecast to change very little from existing conditions. Approximately 14 acres, or 3% of the sub-watershed, of open urban land and forest, are projected to be developed as residential land use. residential subdivisions within the sub-watershed include Marywood, Kingswood, Hollybrook, Druid Hills, Indigo Park, La Fontaine, and Winston Terrace (Figure 11).

Given that this is a small number of acres relative to the area of the sub-watershed and the fact that 20% of the sub-watershed is already impervious, it is likely that future development will have little impact on the sub-watersheds pollutant loads.

Figure 11 – TAZ 1845 & 202 Sub-watershed with Impervious cover Structures and Roads in red, RPAs in green.

Sub-watershed 204

Sub-watershed 204 (Figure 12) is 554 acres in size with a substantial 132 acres (24%) of impervious cover, placing it just within the Impacted category of the CWP’s Impervious Cover Model. Jamestown Road bisects the western side of the sub-watershed. Approximately 19 acres of

wetlands and 95 acres of RPA lands fall within the sub-watershed boundary. The vast majority of the sub-watershed is zoned as residential (491 acres), though there is some business zoning (approximately 44 acres) in the north consisting of Colony Square and Williamsburg Office Park.

Residential subdivisions and within the sub-watershed include Rolling Woods, Kingswood, Springdale, Boughsprings, Winston Terrace, Hollybrook, Lake Powell Pointe, and Birchwood Park and Marlboro (Figure 13). Like sub-watershed 203, most of the impervious cover is in the upper

watershed, though this development is considerably older, and as such, there is relatively little stormwater treatment.

The sub-watershed is about 23 percent impervious overall. Of the total of 167.9 impervious acres, about 40 percent is made up of pavement such as roads and parking lots, and a similar amount is from buildings.

Pollutant loading is forecast to change very little from existing conditions. Approximately 2 acres, or less than 1% of the sub-watershed, of open urban land and forest, is projected to be developed as residential land use. Given that this is a small number acre relative to the area of the sub-watershed and the fact that 24% of the sub-watershed is already impervious, it is likely that future development will have little impact on the sub-watersheds pollutant loads.

Figure 13- TAZ 1810 & 204 Sub-watershed with Impervious cover Structures and Roads in red, RPAs in green.

*Assessment Summary of Impervious Surface for the Mill Creek Watershed

Sub-watershed 201, 202, 203, and 204 in 2011 future assessment was based on “Given that this is a small number of acres relative to the area of the sub-watershed” and its current Impacted rating “it is likely that future development will have little impact on the sub-watersheds pollutant loads.”

Ate the time of the study in 2011 the watershed was rated as Impacted and the known issues identified were-

* Bacteria levels in Mill Creek are too high for recreational swimming or food consumption.

* Headwater streams throughout the watershed show signs of deterioration due to increased stormwater flows from development. Sediment from the eroding streams is causing problems for downstream properties throughout the watershed, by clogging available drainage areas and altering stream flow channels. Streambank erosion occurs from upstream urbanization.

* Often during hurricanes, nor’easters, and other severe rainstorms, garage and yard flooding occurs in the lower watershed, with some lots flooding in a typical rainstorm.

* Assessments of the Mill Creek neighborhoods determined that about half the lawns are high-maintenance, which can add excess nutrients into the waterways.

* Neck O’ Land Road area is vulnerable to James River tidal flooding. On-going sea-level rise will contribute to increased impacts from tidal flooding.

To date in the Mill Creek Watershed the county has invested in 22 stormwaters projects, 8 of which were stream restorations projects at a total cost of $2,806,692 to mitigate these 2011 known issues. In the FY 20-24 Capital Investment Program (CIP) the Mill Creek Watershed has two more stream restoration projects at a cost of $800,000.

The Neck-O’Land will see increased impacts from tidal flooding with the 1.5Ft sea level rise (additional information is in the Sea Level Rise 1.5ft and the Ware Creek Watershed section)

As to the future condition of “ …that future development will have little impact on the sub-watersheds pollutant loads.” Mill Creek Watershed in 2045 is forecasted as a plus 1,185 Household. The most impervious portions of the watershed – sub-watersheds 201, 202, 203, and 204 currently has 78 parcels with the addition of the Promenade which was not in the 2011 study. The forecast for these four watersheds which inclusive of TAZs 1810, 1811,1 844 and 1845 is a plus 496 Households in 2045 (Figure 14).

Figure 14- TAZs 1810, 1811, 1844 and 1845 is a plus 496 Households in 2045 for Sub-watersheds 201, 202, 203, and 204

Not included in the study was the section at the mouth of Mill Creek where there are six subdivisions with 81 vacant parcels and a forecast of plus 689 Households in 2045 which are in TAZs 1813 and 1817 Figure 15

Figure 15- Sub-watershed at the mouth of Mill Creek 689 Households in 2045 which are in TAZs 1813 and 1817

Summary Assessment Conclusion

The total Mill Creek Watershed has 519 vacant parcels in 2019. It is hard to imagine an additional 1,185 Households in the Mill Creek Watershed but if it does that means more impervious surface with the concurrent ill-effects to the habitat. The last 12 years of stormwater projects will have mitigated the future health of the watershed but not completely given future development and growth.

Sea Level Rise 1.5ft and the Mill Creek Watershed

The Planning District Commission’s (HRPDC) Sea Level Rise Planning Policy and Approach, use for planning purposes for the period 2018-2050: 1.5 feet of sea-level rise above current MHHW (mean higher high water. The impact of sea-level rise in the watershed at the mouth in the tidal main stem of Mill Creek. The mouth of the Mill Creek Watershed today 2018 Figure 16. There is a significant inland migration as far as Jamestown Road as it crosses Lake Powell with an unobstructed expansion of the tidal marshlands.

Figure 16 – *The mouth of the Mill Creek Watershed* today 2018

*Figure 17- Sea Level Rise 1.5ft and the mouth of the Mill Creek Watershed*

The 2011 Mill Creek Watershed Management Plan makes no mention of any salinity issues, unlike the 2003 Yarmouth Creek Management which documented increasing saltwater concentration in the freshwater tidal ecosystem.

It is reasonable to assume that with a sea-level rise that salinity and vegetation changes will occur in the dark blue areas of the tidal main stem of Mill Creek (Figure 17). Sea-level rise will alter the future freshwater tidal ecosystem of the tidal portion of the watershed.

Neck-O’Land at the mouth of the Mill Creek on the east side of Mill Creek will see increased impacts from tidal flooding with the 1.5Ft sea level rise.

The extent of these changes, while unknown requires further study and investigation. One of the ongoing research projects by Karinna Nunez, Virginia Institute of Marine Science (VIMS) is a modeling effort of tidal marshes to simulate and assess the evolution and persistence of tidal marshes under different sea-level rise scenarios. The intended outcome is “highly resolved outputs that will allow coastal planners to more accurately identify the potential future location of marsh habitats where protection and restoration activities can be focused to increase tidal marsh resilience.” The initial development of her model prototyped the Taskinas Creek marshlands.

Stay the course

This assessment was undertaken to describe the quantitative impact on the environment and by inference, the qualitative impact on the rural character as well as community character. The assessment outcome was to identify opportunities that would close the gap between what we think is important and what we are not satisfied with.

Preserving rural character – 16% (85% important vs. 69% satisfied)
Protecting environment – 15% (85% important vs. 70% satisfied)

A large part of this paper is a deep dive into the specific areas of a sub-watershed to determine the future state of its water quality and habitat health by examining the range of their impervious surface cover 0%-10% sensitive but ok 10%-25% impacted and degradation of water quality and habitat health. Increasing development means increasing impervious cover surface but there are mitigation strategies, policies, and ordinances that the county adheres too.

AFD, PDR an Other Conservation Easement Programs

Another part of this paper was examining areas within the watershed that are unique and are defining parts of our rural character. Protecting, Preserving, and Conserving these areas through the Agricultural and Forestry Districts (AFD), Purchase of Development Right (PDR), programs and other conservation easement programs is the other half of the strategy to limit development and protect the Sensitive impervious surface rating for the other sub-watersheds.

AFD

Figure 12 below shows the watersheds only AFD the Gospel Spreading Church in dark purple There are 4 of the 8 the AFD parcels that are also PDR conservation easements and one parcel that is only in the PDR program The five parcels in the PDR program are a permanent conservation easement. Four of the AFD parcels are in a temporary conservation easement for the renewal five-year period. The two largest AFD parcels east of Mill Creek and that is a temporary conservation easement, total 861 acres and border the Colonial Parkway overlooking the James River the Upper ware Creek sub-watershed. Figure 18 shows the impact of 1.5ft SLR on the Gospel Spreading Church AFD

Figure 18 – AFD Gospel Spreading Church in dark purple

*Figure 19- AFD Gospel Spreading Church in dark purple* impacted by 1.5 ft SLR

The Mill Creek Watershed AFD tax rate totals $22,331 annually. The difference from the full tax rate that county forgoes in tax revenue is $493,225 for the 5yr life cycle of the AFD parcel.

The AFD program in the Mill Creek Watershed preserves the environment at the mouth of Mill Creek and with sea-level rise allow for an unobstructed migration inland of the marshlands (Figure 19 ) In the case of the Gospel Spreading Church AFD it acts as a buffer for the Colonial Parkway providing a rural and historical backdrop.

PDR & Greenspace

The county to date has spent $30.1M for the PDR and Green-space and there is an initiative to resume the program. Figures 20 shows the PDR parcel tan in the Mill Creek Watershed. The Gilley parcels is in both the PDR and Green-space program and in 2013 the county purchased a conservation easement for the parcel for $1.19M

Figure 20 – Mill Creek Watershed PDR parcels in gold

Opportunities

The two largest Gospel Spreading Church AFD parcels east of Mill Creek are in a temporary conservation easement and have a total of 861 acres. The parcel borders the Colonial Parkway overlooking the James River providing a rural and historical backdrop as it looks out over Jamestown Island

The conservation and preservation of this area to the ecosystem services it provides to wildlife and plant habitat are significant.

In Closing

Sea-level rise will alter the future freshwater tidal ecosystem at the mouth of Mill Creek. The extent of these changes, while unknown requires further study and investigation. Prototyping work by VIMS on modeling tidal marshes to simulate and assess the evolution and persistence of tidal marshes under different sea-level rise scenarios. Further study should be actively pursued by the Commonwealth or in partnership with the county since it has interests on the effects of sea-level rise on county marshlands along the Lower Chickahominy and James River

References

Mill Creek Watershed Plan Vanasse Hangen Brustlin, INC and KCI Technologies Jul 2011

(Schueler, 1994)

Schueler, T.R. 1994. The Importance of Imperviousness. Watershed Protection Techniques. 1(3): 100-111.

The GIS data is that makes up the majority of the graphics in all six papers is from the Hampton Roads Transportation Planning Organization (HRTPO), Janes City County GIS, and the Department of Conservation and Recreation’s Virginia Conservation Lands Database The remains graphics used are from the specific watershed plan

Engage 2045 – Powhatan Creek Watershed

Powhatan Creek Watershed Overview

Figure 2 – Impervious surface cover in red consisting of structures and roads in the Powhatan watershed.

The Powhatan Creek Watershed Management Plan of November 2001 by the Center for Watershed Protection (CWP) described the 22 square mile Powhatan Creek watershed as

“… truly a state and national treasure with its historic past and present biodiversity.”

The impervious assessment of the Powhatan Creek Watershed is unique in that it is the most urbanized of all eight watersheds and its impervious surface cover was documented at two separate time frames 1998 and 2008. From the 2001 study using the 1998 data it said, “In 1970, the watershed impervious cover was estimated to be 3%, but grew to 8% in 1998, 9.8% in 2000, and is projected to reach a maximum of 15.5% in the future.” The 2001 CWP study determined that the 2001 impervious surface was 10.95% and the predicted future was 16.78%. The 2008 Powhatan Creek Flood Plain Study by the Williamsburg Environmental Group (WEG) said based on updated rainfall data and reexamination of the hydrology of the watershed’s impervious surface in 2008 was 16.42% and the future was 21.18%. Figure 2 above shows in red the current impervious cover of structures and roads in the Powhatan watershed.

We are now 10 plus years into the future from that 2008 WEG study and the question is what is the current impervious surface cover? It was predicted at 21.18% or is it greater? Either way, the percentage is in the Impacted range of 10% -25%. The question is whether the watershed has moved closer to the Non -Supporting, a range of 25% -100%?

The rapid development seen in the last three decades poses a threat to water quality and natural habitats in the Powhatan Watershed. Prior research has shown that stream and wetland quality begins to decline when the amount of impervious cover in a watershed exceeds 10%.

The 2001 CWP study pointed out that –

“The principal effects of impervious cover in Powhatan Creek include:

* Changes in the hydrology of streams, wetlands, and floodplains

* Increased pollutant loads delivered in urban stormwater (bacteria, sediment, nutrients)

* Channel erosion in headwater streams

* Water level fluctuations that degrade wetlands and rare, threatened, or endangered plant species

habitat

What the WEG 2008 study has projected for a future overall impervious surface for the watershed is 21.8%, Two of the sub-watersheds were over the 25% threshold and into the non-supporting range and five were in the 19%-23% range. The details are in Figure 3 below which are the 2001CWP sub-watersheds locations and Figure 4 is from the WEG 2008 study that compares 2007 and Future impervious cover with the previous 2001 CWP study sub-watersheds 2000 and Future.

It is probably fair to say that those future projections are the current status for the Powhatan Watershed and its 10 sub-watersheds in 2019.

To date in the Powhatan watershed, the county has invested in 30 stormwaters projects, 5 of which were stream restorations. Still unknown is if these mitigation projects have helped the downstream wetlands and rare, threatened, or endangered plant species. The county has undertaken to fund an updated Powhatan Watershed Management Plan in the county’s next 5-year Capital Improvement Program (CIP) FY 20-25.

Figure 3 – CWP 2001 Powhatan Watershed Plan Study Area

Figure 4 – From the WEG 2008 study that compares 2007 and Future impervious cover with the previous 2001 CWP study sub-watershed 2000 and Future

Assessment of Impervious Surface for the Powhatan Creek Sub-watershed

The Powhatan Creek Watershed Management Plan of November 2001 by the Center for Watershed Protection (CWP) described the 22 square mile Powhatan Creek watershed as

“… truly a state and national treasure with its historic past and present biodiversity.”

The impervious assessment of the Powhatan Creek Watershed is unique in that it is the most urbanized of all eight watersheds. This impervious surface cover was documented at two separate time frames 1998 and 2008. From the 2001 study using the 1998 data it said, “In 1970, the watershed impervious cover was estimated to be 3%, but grew to 8% in 1998, 9.8% in 2000, and is projected to reach a maximum of 15.5% in the future.” The 2001 CWP study determined that the 1998 survey that impervious surface was 10.95% and the predicted future was 16.78%. The 2008 Powhatan Creek Flood Plain Study by the Williamsburg Environmental Group (WEG) stated that based on updated rainfall FEMA data and reexamination of the hydrology of the watershed’s impervious surface in 2008 was 16.42% and the future was 21.18%. Figure 3 shows in red the current impervious cover of structures and roads in the Powhatan watershed.

The 2001 CWP study said –

“The principal effects of impervious cover in Powhatan Creek include:

* Changes in the hydrology of streams, wetlands, and floodplains

* Increased pollutant loads delivered in urban stormwater (bacteria, sediment, nutrients)

* Channel erosion in headwater streams

* Water level fluctuations that degrade wetlands and rare, threatened, or endangered plant species habitat

It is probably fair to say based on increased development that those future projections in 2008 are the current status in 2019 for the Powhatan Watershed and its 10 sub-watersheds in 2019.

The percentage of the impervious cover has exceeded the 10% threshold and has impacted water, streams and wetland quality. But on the other hand, the county has taken steps to mitigate channel erosion in streams and pollutant loads delivered in urban stormwater (bacteria, sediment, nutrients). To date in the Powhatan watershed the county has invested in 30 stormwaters projects, 5 of which were stream restorations. Still unknown is if these mitigation projects have helped the downstream wetlands and rare, threatened, or endangered plant species. The county has undertaken to fund an updated Powhatan Watershed Management Plan in the county’s next 5-year Capital Improvement Program (CIP) FY 20-25.

If we assume that the 2019 overall impervious cover is the WEG’ study’s Future impervious cover of 21.8% and that two of the sub-watersheds are in 2019 over the 25% threshold and into the non-supporting range and five were in the 19%-23% Impacted range what is the prognosis for 2045?

Figure 5 – Powhatan watershed’s 11 TAZs 2015 compared to the projected 2045 population, households and vehicles

Figure 5 indicates a 33% increase in population for the watershed over 2015, a 37% increase for households and a 31% increase in vehicles. That means 4,123 new households either in a new home or apartment with supporting roads with more impervious cover in the watershed.

The highest 2045 growth occurs in 4 out of the 11 TAZs and continues to occur in those same 5 sub-watersheds where 2 were over 25% and 3 were in the 20%-23% impacted range.

Figure 6 – 207 Upper Chisel Run sub-watershed

The 207 Upper Chisel Run sub-watershed (Figure 6)with a 29.30% Impervious cover is in TAZ 1832 and 1831. When comparing 2015 to 2045, TAZ 1832 will have 519 less in population and 208 less in the number of households. TAZ 1831 for the same timeframe will have105 less in population and 7 less in the number of households by 2045.

Good news except there is still a 111-acre vacant parcel own by The Colonies Williamsburg Timeshares. There are two already developed timeshare properties the Williamsburg Plantation, The Colonies Williamsburg Timeshares, besides the other neighborhoods of Williamsburg West, Windsor Forrest, Chisel Run and Regency On Longhill. These timeshares are at the headwaters of the Upper Chisel Run Creek of the Powhatan watershed. Also, the Prime Outlets, Ewel Station shopping center and New Town’s rainwater from the Lower Chisel Run Creek drains into the main stem of Chisel Run Creek. The combination of these three, the timeshares, Prime Outlet/Ewell Station and New Town are likely to continue to impact water quality and unintended consequences on the habitat.

Flooding

Another unintended consequence is increased flooding in areas within the watershed. Chisel Run Creek joins with Longhill Swamp to form the start of Powhatan Creek between the neighborhoods of Windsor Forrest and Fords Colony. Where the Powhatan crosses Edinburgh Drive in Ford’s Colony flooding is occurring more frequently. Downstream as the Powhatan exits Ford’s Colony at News Road the county is planning a stormwater project to armor the area to mitigate flooding issues across News Road (Figure 8).

Sub-watershed 206 (Figure 7) contains the neighborhoods of Village at Westminster, Forrest Heights, Scots Pond, Seasons Trace, Heron Run Rain Tree, Rain Tree Village, and the shopping centers Prime Outlet and Ewell Station. The impervious cover is 21.30%, the fifth-highest in the Powhatan watershed. The sub-watershed is in 1836 and 1837 TAZs – which by 2045 will see an additional 363 households. The2045 impervious cover should remain in the lower 20% range. The neighborhoods of Village at Westminster, Forrest Heights, Scots Pond, Seasons Trace, Heron Run drain into the upper headwaters of a branch of Long Hill Swamp creek. The other branch of Long Hill Swamp in adjoining TAZ 1835 merges into the main stem of Long Hill Swamp across from Lafayette High School on Longhill Rd and continue to join with the Chisel Run Creek to form the start of the Powhatan Creek.

Figure 8 – Upper Powhatan Sub Watersheds Impervious Cover flooding impact on Long Hill Road, Edinburgh Drive and News Road

The flooding is likely to occur where both branches of the Long Hill Swamp Creek cross Longhill Road by the entrance of Season’s Trace and on the west side of Lafayette High School (Figure 8). The upper reaches of the LongHill Swamp Creek branch in the 1835 TAZ is not likely to see an increase in development with a substantial section in the Warhill Sports Complex except if the 312-acre Armistead AFD property that is in The PSA is developed. The combination of the increasing impervious cover with more rainwater draining into Long Hill Swamp Creek and Chisel Run Creek exacerbates flooding issues near Edinburgh Drive and News Road. (Figure 8)

The second highest impervious cover at 27.13% is the sub-watershed 208 (Figure 9) which contains Eastern State and Newtown. Development is still ongoing with 124 vacant parcels as of 2019 TAZ 1812. There is in the 1812 TAZ a 1,192 increase in population, a 61% increase along with a 608 household plus up, a 68% increase by 2045. We should expect to see a higher percentage of impervious cover and consequences on water quality

TAZ 1833 contains sub-watershed 209 (Figure 10) neighborhood’s Ford’ s Colony, Spring Hill, Windsor Meade, Founders, Village Monticello, Windsor Mead, and Monticello Market Place. It is the fifth-highest growth TAZ in the county with a 3,745 gain in population by 2045. The impervious cover is 21.88% and with the 2045 additional 1,315 households, we will see accompanying increases in impervious surface and water quality issues.

210 sub-watershed (Figure 11) contains the neighborhood’s Powhatan Plantation, Powhatan Secondary Powhatan Woods Powahatan Crossing and has a 21.18% Impervious cover. The subwatershed is in TAZ1819 which by 2045 will see an increase in the population of 2,526 and see an additional 1,426 household. The 2045 impervious cover is likely to increase into the mid 20 percentile.

Assessment Summary of Impervious Cover for Powhatan Creek Watershed

It is reasonable to believe that the of 5 sub-watersheds – 2 over 25% and 3 in the 20%-23% impacted range will stay about the same by 2045 but this is conjecture based on a 2007 prediction on their future state and the projected increase in households. With the 0%-25% level of impious cover in the 5 sub-watershed, there is the issue of flooding. On average the county gets 47 inches of rain a year the number of days of 1 inch of rain or more is on the increase. Where there is more rain runoff, heavy rain will lead to more flooding. 1 inch of rain in the Powhatan watershed of 22.5 square miles is enough to fill 584 Olympic swimming pools or would cover 10,927 football fields (Figure 12)

Figure 12 – How Much is an inch of Rain?

To date in the Powhatan Creek Watershed the county has invested in 35 stormwaters projects, 1 of which were stream restorations projects at a total cost of $1,080,128 to mitigate these 2001 known issues.
In the FY 20-24 Capital Investment Program (CIP) the Powhatan Creek Watershed has flood mitigation, drainage, and water quality improvement projects at a cost of $1,100,000.
Also, the Neighborhood Drainage program from 2016-2018 had 35 projects that in total came to $725,094 of which the county paid $327,988 of that total.
From 2008 to 2024 the county will have spent $2,508,116 to mitigate the effects of growth on her watershed.

The study will provide an update to verify the impervious surface cover as well as the state of water quality habitat and wetlands.

Attempts to maintain the Armistead and Gordon Creek AFD in a temporary or permanent conservancy is to the county benefit not to add more impervious cover.

Sea Level Rise -Powhatan Creek

The Planning District Commission’s (HRPDC) Sea Level Rise Planning Policy and Approach, use for planning purposes for the period 2018-2050: 1.5 feet of sea-level rise above current MHHW (mean higher high water. The impact of sea-level rise in the watershed in the 2045 timeframe is along the main stem of Powhatan Creek and shows significant inland migration and expanse of the non-tidal marshlands as far as the by the neighborhood of St. Georges 100 near John Tyler Highway, Route 5. In this area, it does not appear to be any impediments to the inland migration or expansion of what might now become tidal marshland with sea-level rise

Figure 13 – Extent of Sea Level Rise in Tidal area of Powhatan Creek from John Tyler to below Jamestown Road with conservation easements

Figure 14 – The Inland extent of Sea Level Rise 1.5Ft in dark blue by StGeorge 100 near John Tyler Highway with conservation easements

Figure 15 – Sea Level Rise 1.5Ft in dark blue by Jamestown 1607, Landfall at Jamestown and Powhatan Shores with conservation easements

Figure 16 – SLR1.5 in dark blue showing 2050 Powhatan Creek with 2020 Powhatan Creek in light blue and 2020 Resource Protection area in Green and Red hash area is the 2020 marshlands most of it in a permanent conservation easement

The most significant impact of sea-level rise is in the area around the neighborhoods of Jamestown 1607, Landfall at Jamestown and Powhatan Shores. Figure 16 shows the new Powhatan Creek in 2050 with a sea-level rise of 1.5ft. In light blue is the current 2020 Powhatan Creek and current 2020 Resource Protection (RPA) area in Green. County ordinance defines RPA as “a buffer *area* not less than 100 feet in width located adjacent to and landward of the components of Tidal Wetlands, Non-Tidal wetlands and Tidal Shores along both sides of any water body with the perennial flow.” Given a new 2050 stream geometry, the 2050 RPA will buffer will extend 100feet on both sides of the new 2050stream. Also, Figure 16 shows the 2020 tidal marsh area in a red hash marking. It is reasonable to assume that the current marshlands will migrate landward were not impeded by bulkheads.

The last area of concern with sea-level rise is the bridge across Powhatan Creek on Jamestown Road (Figure 16 and 15). The bridge can act as a “dam” during flooding conditions on the Powhatan. With the sea-level rise and flooding conditions that “dam” may cause flooding conditions in neighborhoods on both sides of Jamestown Road. The flooding conditions in 2003 with Isabel, a category 1 hurricane, flooded the Jamestown 1607 neighborhood causing widespread property damage.

The same conditions of a “dam “exist with the narrow culverts across the Powhatan at Route 5, News Road, Edinburgh Drive, Longhill

Road and Seasons Trace. The Route 5 Culvert Crossing Flooding Study 2008 Revised: December 2008 by Williamsburg Environmental Group, Inc. documents the issue of Route 5, News Road and Longhill Rd and Seasons Trace.

Stay the Course

* Preserving rural character – 16% (85% important vs. 69% satisfied )
Protecting environment – 15% (85% important vs. 70% satisfied)

As we said at the beginning the Powhatan Watershed is the most urbanized and has the highest Impacted percentage of all the subwatershed -5 sub-watersheds – 2 over 25% and 3 in the 20%-23% all impacted range of 10% – 25%.

AFD, PDR an Other Conservation Easement Program

AFD

Figure 17 shows the location of the Armistead AFD in TAZ 1835 and Gordon Creek AFD in TAZ 1840.

Figure 17 – Armistead AFD in TAZ 1835 and Gordon Creek AFD in TAZ 1840

The 1835 TAZ for 2045 shows both a reduction in population and households. There are no vacant developmental type parcels in the TAZ. The exception is the 312-acre Armistead AFD property that is in the PSA if it would be withdrawn from its current temporary conservation easement.

The 1840 TAZ see a doubling in population and household s by 2045 –

1079 to 2102 for population and 483 to 979 for households more than likely by the Greenspings properties. The withdrawal of the 109 acres Gordon Creek parcel off of News Road and in the PSA would more than likely move the 12.3% impervious cover higher into the Impacted range 10%-25%

The Cost – Agricultural and Forestall Districts (AFD)

The Powhatan Watershed AFD’s tax rate totals $3,125 annually. The difference from the full tax rate that county forgoes in tax revenue is $221,765 for the 5yr life cycle of the AFD parcel. The AFD program in the Powhatan Creek Watershed preserves the environment and provides wildlife and plant habitat, water resources protection, erosion control, and sediment retention eco-services to the sub-watersheds.